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For the discussion of catfish systematics. Post here to draw our attention to new publications or to discuss existing works.
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Morphology & behavior of sound production in Pterygoplichthys pardalis

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Slusher, Monique Renee. (2018). "Morphological Correlates and Behavioral Functions of Sound Production in Loricariid Catfish, With a Focus on Pterygoplichthys pardalis (Castelnau, 1855)". Dissertations and Theses. Paper 4155.
https://pdxscholar.library.pdx.edu/open ... _etds/4155
http://dx.doi.org/10.15760/etd.6043
Persistent Identifier: http://archives.pdx.edu/ds/psu/23894
Slusher wrote:Abstract
The Neotropical catfish produces a harsh stridulation sound upon manual capture. This stridulation sound is made on the abduction of the pectoral fin spine, and is accomplished by friction of a ridged dorsal condyle against a rough spinal fossa of the cleithrum in the pectoral girdle. The sound produced has an average frequency of 121 Hz, and is used with other anti-predator adaptations such as bony subdermal armor and defensive fin-spreading. Pterygoplichthys pardalis does not display behavioral modification in response to conspecific stridulation sound, and therefore it is likely that stridulation sound in P. pardalis is being used as a predator deterrent.
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Reproduction of Hypostomus hemicochliodon, cave effects

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Pacaya Flores, F. (2018). Reproduction in captivity of the "brown carachama" Hypostomus hemicochliodon (loricariidae), in the "Carlos Miguel Castañeda Ruíz" research center. IIAP. San Martín.

Pacaya Flores, F. (2018). Reproducción en cautiverio de la “carachama parda” Hypostomus hemicochliodon (loricariidae), en el centro de investigaciones “Carlos Miguel Castañeda Ruíz”. IIAP. San Martín.

http://renati.sunedu.gob.pe/handle/sunedu/210679
The present study was carried out at the "Carlos Miguel Castañeda Ruiz" Research Center of the IIAP - San Martín Headquarters, located in the Bello Horizonte hamlet of Banda de Shilcayo district, during the months of May 2014-January 2015; aiming to establish a captive reproduction mechanism of the "Brown Carachama" by proposing three treatments: T1 (PVC nests), T2 (Bamboo stem nests) and a control treatment (natural nests), each treatment with 3 replicas, randomly distributed, each replicate in an area of ​​250 m2, with 180 reproducers of Hypostomus hemicochliodon, randomly distributed 20 individuals per experimental unit. After an adaptation period of 60 days, the experimental phase began. The reproductive samplings and physical-chemical parameters of the water in the ponds were carried out every two weeks. 32 reproductive events were obtained, with T0 (59%) being the most responsive, followed by T2 (25%) and T1 (16%). It was concluded statistically (p> 0.05) that there is a significant difference (value p = 0.0191), indicating in the number of individuals obtained, T1 was better (T1> T2> T0). There is also a significant difference in the weight (g) of eggs obtained, indicating that T1 and T2 are equal, and both are greater than those obtained from T0. The results of the physico-chemical parameters of the water indicate that the Hypostomus hemicochliodon reproducers have a wide range of tolerance compared to their natural environment, achieving their reproduction in captivity.
El presente estudio se realizó en el Centro de Investigaciones “Carlos Miguel Castañeda Ruiz” del IIAP – Sede San Martín, ubicado en el caserío Bello Horizonte del distrito Banda de Shilcayo, durante los meses de Mayo del 2014-Enero del 2015; teniendo como objetivo establecer un mecanismo de reproducción en cautiverio de la “Carachama parda” Hypostomus hemicochliodon mediante el planteamiento de tres tratamientos: T1 (Nidos de PVC), T2 (Nidos de tallo de Bambú) y un tratamiento testigo (Nidos naturales), cada tratamiento con 3 réplicas, distribuidas al azar, cada replica en un área de 250 m2, con 180 reproductores de Hypostomus hemicochliodon, repartidos al azar 20 individuos por unidad experimental. Luego de un periodo de adaptación de 60 días, se inició la fase experimental. Se realizó quincenalmente los muestreos de reproducción y de parámetros físico-químicos del agua de los estanques. Se obtuvieron 32 eventos reproductivos, siendo el de mayor respuesta el T0 (59%), seguida del T2 (25%) y el T1 (16%). Se concluyó estadísticamente (p > 0.05) que existe diferencia significativa (valor p = 0,0191), indicando en el número de individuos obtenidos, el T1 fue mejor (T1>T2>T0). Además existe diferencia significativa en el peso (g) de ovas obtenidas, señalando que el T1 y T2 son iguales, y ambos mayores a los obtenidos del T0. Los resultados de los valores de parámetros físico-químicos del agua nos indican que los reproductores de Hypostomus hemicochliodon tienen un amplio rango de tolerancia en comparación a su medio natural, logrando su reproducción en cautiverio.
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Molecular biodiversity of Hypancistrus zebra

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MAGALHÃES, Maithê Gaspar Pontes. 2018. Description of Molecular Biodiversity of Hypancistrus zebra (Loricariidae: Siluriformes), a Species of Ornamental Fish Threatened with Extinction. Dissertation (Master's Degree in Computational Biology and Systems) - Instituto Oswaldo Cruz, Oswaldo Cruz Foundation, Rio de Janeiro, 2018.

MAGALHÃES, Maithê Gaspar Pontes. 2018. Descrição da Biodiversidade Molecular de Hypancistrus zebra (Loricariidae: Siluriformes), uma Espécie de Peixe Ornamental Ameaçada de Extinção. 2018. 77 f. Dissertação (Mestrado em Biologia Computacional e Sistemas)-Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, 2018.

https://www.arca.fiocruz.br/handle/icict/28446
ABSTRACT
The impact of human activities on Earth is so deep that a new geological epoch, the Anthropocene, has been widely debated. In this new epoch, biodiversity loss stands out among the key features affecting global health. The construction of dams for hydroelectric power generation has the potential to have a major impact on local fauna, especially in regions with high biodiversity and endemism, such as the Brazilian Amazon. is a species of fish endemic to the Big Bend of the Xingu River, in the Amazon basin, threatened with extinction due to the impact of the Belo Monte Power Plant dam and illegal capture for international fish aquarium. However, until the beginning of this work, only two nucleotide sequences were available from Genbank and the BOLD System, the main public databases of this type of information In this work, seven transcripts of different organs of Hypancistrus zebra were sequenced. We produced more than 200 million readings used to assemble over half a million transcripts. In the generated database, we identified more than 35,000 single nucleotide variants (SNVs) and almost four thousand insertions and deletions (indels) distributed among the seven organs of H. zebra. From the analysis of these data, we developed pairs of primers for amplification of indels identified in six transcripts and of frames with at least three SNVs identified in seven other transcripts. We suggest this set of transcripts as the most suitable for application in works aiming the conservation of this species. Mobile genetic elements of several families were found and expressed in the seven organs. The frequency of transcripts with mobile genetic elements varied from 12% in the transcriptome of the heart to 33% in the gill. In addition, we assembled the mitochondrial genome, with 16,330 bp, of this species. The information and the database produced in this work reduces the knowledge gap on the genetic diversity of Hypancistrus zebra and can be used for population genetics studies and the conservation of this and other phylogenetically close species. This information, especially those related to genetic genetic elements, can also support research on the karyotype variation found in the Loricariidae family, of which H. zebra is a part.
  • KEYWORDS: Transcriptome, Mitochondrial Genome, Catfish, Biodiversity
RESUMO
Os impactos das atividades humanas na Terra são tão profundos que a proposta de definição de uma nova época geológica, o Antropoceno, tem sido amplamente debatida. Nesta nova época, a perda da biodiversidade destaca-se entre as principais características que afetam a saúde global. A construção de barragens para geração de energia hidrelétrica tem potencial de causar grande impacto na fauna local, especialmente em regiões com elevada biodiversidade e endemismo, como a Amazônia brasileira. O é uma espécie de peixe endêmico da Volta Grande do rio Xingu, na bacia amazônica, ameaçada de extinção devido ao impacto da construção da barragem da Usina de Belo Monte e à captura ilegal para aquariofilia internacional. Apesar disso, até o início desse trabalho, apenas duas sequências de nucleotídeos eram disponíveis no Genbank e no BOLD System, principais bancos de dados públicos desse tipo de informação. Neste trabalho, foram sequenciados sete transcriptomas de diferentes órgãos de Hypancistrus zebra Produzimos mais de 200 milhões de leituras utilizadas para montar mais de meio milhão de transcritos. Neste banco de dados produzido, identificamos mais de 35 mil variantes de nucleotídeo único (SNVs) e quase quatro mil inserções e deleções (indels) distribuídos entre os transcriptomas dos sete órgãos de H. zebra. A partir da análise desses dados, desenvolvemos pares de iniciadores para amplificação de indels identificados em seis transcritos e de janelas contendo pelo menos três SNVs identificadas em sete outros transcritos. Sugerimos esse conjunto de transcritos como os mais adequados para aplicação em trabalhos visando a conservação dessa espécie. Foram encontrados elementos genéticos móveis de diversas famílias e expressos nos sete órgãos. A frequência de trancritos com elementos genéticos móveis variou de 12% no transcriptoma do coração a 33% na brânquia. Além disso, montamos o genoma mitocondrial, com 16.330 pb, dessa espécie. As informações e o banco de dados produzidos neste trabalho reduzem a lacuna de conhecimento sobre a diversidade genética do Hypancistrus zebra e podem ser usados para estudos de genética de população e da conservação dessa e de outras espécies filogenéticamente próximas. Essas informações, em especial às relacionadas a elementos genéticos móveis, também podem dar apoio à investigação sobre a variação cariotípica encontrada na família Loricariidae, da qual o H. zebra faz parte.
  • PALAVRAS-CHAVE: Transcriptoma, Genoma Mitocondrial, Peixes-Gato, Biodiversidade
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Diversity of Trichomycterus in the Rio Doce basin

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EDIT: 20/11/22 - This is now published here.

Ten new species proposed:
  • sp. nov.
  • T. barrocus sp. nov.
  • T. brucutu sp. nov.
  • T. illuvies sp. nov.
  • T. melanopygius sp. nov.
  • T. ipatinguensis sp. nov.
  • T. pussilipygius sp. nov.
  • T. sordislutum sp. nov.
  • T. vinnulus sp. nov.
  • T. tantalus sp. nov.
Reis, V. J. C. (2018). Diversity of the genus Trichomycterus Valenciennes, 1832 (Siluriformes, Trichomycteridae) in the Rio Doce basin: a systematic study integrating phenotypes, DNA and classical taxonomy. Master's Dissertation, Museu de Zoologia, University of São Paulo, São Paulo. doi:10.11606/D.38.2018.tde-08102018-132640. Retrieved 2019-07-08, from www.teses.usp.br

http://www.teses.usp.br/teses/disponive ... 640/en.php

Reis, V. J. C. (2018). Diversidade do gênero Trichomycterus Valenciennes, 1832 (Siluriformes, Trichomycteridae) na bacia do Rio Doce: um estudo sistemático integrando fenótipos, DNA e taxonomia clássica. (Dissertação, Museu de Zoologia, Universidade de São Paulo).
ABSTRACT
The diversity of the genus Valenciennes 1832 in the Rio Doce basin is investigated using conventional and modern morphology and DNA analyses. The work is presented in two Chapters. Chapter One, entitled Diversity of the genus Trichomycterus Valenciennes, 1832 (Siluriforms, Trichomycteridae) in the Rio Doce basin: a systematic study integrating phenotypes, DNA and classical taxonomy integratively analyzes specimens of the genus from the entire Rio Doce drainage and adjacent basins, both from available world-wide collections and from active sampling efforts. A combination of phenotypic and DNA (COI barcoding analysis) provides evidence for the existence of 14 species in the basin, 10 of which are new: T. alternatus Eigenmann, 1917; T. argos Lezama et al., 2012; T. astromycterus sp. nov.; T. barrocus sp. nov.; T. brucutu sp. nov.; T. brunoi Barbosa & Costa, 2010; T. immaculatus (Eigenmann & Eigenmann, 1889)] T. illuvies sp. nov.; T. melanopygius sp. nov.; T. ipatinguensis sp. nov.; T. pussilipygius sp. nov.; T. sordislutum sp. nov.; T. vinnulus sp. nov; and T. tantalus sp. nov. . In addition, a lectotype is designated for T. immaculatus and the species is considered as a senior synonym of Sarmento-Soares et al., 2005. Although remarkable, such increase in species number of Trichomycterus in a single drainage matches similar recent increments in some other Southeastern Brazilian basins, such as the Paraíba do Sul and Iguaçu. The kind of differentiation among species herein recognized varies, with some of them being well-differentiated in morphology but not in barcoding data, and others showing the opposite phenomenon. The geographical distribution of each of the 14 species is plotted in the Rio Doce basin. The wide geographical distribution of some species (T. alternatus and T. immaculatus) is explained against data from geomorphological processes and comparative information on their biology. Chapter two, The type specimens of (Eigenmann, 1917) and T. zonatus (Eigenmann, 1918), with elements for future revisionary work (Teleostei, Siluriformes, Trichomycteridae) focuses on the complex taxonomy, nomenclature and type material status of T. alternatus and T. zonatus. The type series of the two species are analyzed in detail, both in morphology and locality data. Osteological information was obtained with conventional and a new technique of radiographic stereo-triplets. Our new data elucidates their species distinctiveness, diagnostic characteristics, type localities and show that T. zonatus does not occur in the Rio Doce basin.
  • Keywords: barcoding, biogeographical dispertion, Integrative taxonomy, Neotropical catfish, species delimitation
RESUMO
A diversidade do gênero Valenciennes 1832 na bacia do Rio Doce é investigada utilizando métodos convencionais e modernos em análises morfológicas e moleculares. Os resultados desta dissertação são apresentados em dois capítulos. Capítulo um, intitulado Diversity of the genus Trichomycterus Valenciennes, 1832 (Siluriforms, Trichomycteridae) in the Rio Doce basin: a systematic study integrating phenotypes, DNA and classical taxonomy examinou espécimes pertencentes a este gênero encontrados no Rio Doce e em bacias adjacentes disponíveis em coleções nacionais e internacionais e coletados durante esta dissertação. O conjunto de dados obtidos através de análises morfológicas e moleculares (COI, DNA barcoding) revelou a existência de 14 espécies na bacia do Rio Doce, das quais 10 novas: T. alternatus Eigenmann, 1917; T. argos Lezama et al., 2012; T. astromycterus sp. nov.; T. barrocus sp. nov.; T. brucutu sp. nov.; T. brunoi Barbosa & Costa, 2010; T. immaculatus (Eigenmann & Eigenmann, 1889)] T. illuvies sp. nov.; T. melanopygius sp. nov.; T. ipatinguensis sp. nov.; T. pussilipygius sp. nov.; T. sordislutum sp. nov.; T. vinnulus sp. nov; and T. tantalus sp. nov. Além disso, é designado um lectótipo para T. immaculatus, espécie aqui proposta como sinônimo sênior de Sarmento-Soares et al., 2005. O acentuado incremento em número de espécies de Trichomycterus para uma única bacia segue um padrão de crescimento em biodiversidade conhecida do gênero para outras drenagens do sudeste brasileiro a exemplo do rio Paraíba do Sul e Iguaçu. Os tipos de diferenciação detectada entre as espécies aqui tratadas variam, com algumas bem corroboradas morfologicamente, porém muito similares ou indiferenciáveis em análise de DNA barcoding, e outras apresentando o fenômeno oposto. As distribuições geográficas de cada uma das 14 espécies são mapeadas com base em todo o material examinado. A ampla distribuição geográfica de algumas espécies (T. alternatus and T. immaculatus) é explicada através de processos geomorfológicos e informações comparativas sobre suas biologias. O capítulo dois, The type specimens of (Eigenmann, 1917) and T. zonatus (Eigenmann, 1918), with elements for future revisionary work (Teleostei, Siluriformes, Trichomycteridae) se concentra em esclarecer a complexa taxonomia, nomenclatura e o status do material tipo de T. alternatus e T. zonatus. As séries tipos das duas espécies foram minuciosamente analisadas tanto para morfologia como para suas respectivas localidades de proveniência. Informações osteológicas foram obtidas através de técnicas de radiografia convencionais e uma nova metodologia chamada stereo triplets. Os dados obtidos corroboram as respectivas espécies como distintas, e permitem uma avaliação precisa de seus respectivos caracteres diagnósticos e localidades tipo. Também se chegou à conclusão que T. zonatus não ocorre na bacia do Rio Doce.
  • Keywords: bagres neotropicais, barcoding, delimitação de espécies, dispersão biogeográfica, Taxonomia integrativa
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Physicochemistry of water at Panaque nigrolineatus holding facilities

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Diaz, Ana Milena. (2018). Evaluation of the physicochemical parameters of the water and the condition of the fins in the real fish (), during the storage in the export warehouse of Bogotá. De La Salle University, Animal Husbandry Program. Bogotá D.C., June 2018.

http://repository.lasalle.edu.co/handle/10185/28740
Full PDF: http://repository.lasalle.edu.co/bitstr ... sAllowed=y

Diaz, Ana Milena. (2018). Evaluación de parámetros fisicoquímic0s del agua y del estado de las aletas en el pez cucha real (), durante el acopio en bodega de exportación de Bogotá. Universidad De la Salle, Programa De Zootecnia. Bogotá D.C., Junio De 2018.

Milena wrote:ABSTRACT
The family of loricariid fish is typically South American, very diverse in forms, sizes and even in eating habits, there are about 500 species, most are for ornamental use. They are very popular fish in aquariums around the world, as they act as cleaners of the glasses of aquariums, by consuming the algae that adhere to them. The genus or cucha real is a species of singular beauty, desired by aquarists from all over the world. In Colombia they are called buckets and in the world they are called plecos or sucker mouth catfish.

The export of fish is based on the capture, stockpiling, handling in the winery and export, which leads to failures on the part of the fishermen in the way they are caught and the bad handling that is given to the fish, which leads to losses of animals or mistreatment of them at the fins level. The present work seeks to analyze whether water quality and post-capture management affects the survival and quality of the fins in individuals stocked in warehouses, prior to being sent abroad.
Milena wrote:Resumen
La familia de los peces loricáridos es típicamente suramericana, muy diversa en formas, tallas
e incluso en hábitos alimentarios, existiendo cerca de 500 especies, la mayoría son de uso
ornamental. Son peces muy populares en los acuarios de todo el mundo, pues actúan como
limpiadores de los vidrios de los acuarios, al consumir las algas que se adhieren a estos. El
género o cucha real es una especie de singular belleza, apetecida por acuarófilos de
todo el mundo. En Colombia se les llama cuchas y en el mundo se les denomina plecos o sucker
mouth catfish.

La exportación de peces se basa en la captura, acopio, manejo en bodega y exportación, lo cual
conlleva fallas por parte de los pescadores en la forma como los capturan y el mal manejo que
se les da a los peces, lo que acarrea pérdidas de animales o maltrato de los mismos a nivel de
aletas. El presente trabajo busca analizar si la calidad del agua y el manejo postcaptura, afecta
la supervivencia y la calidad de las aletas en individuos acopiados en bodegas, previos a ser
enviados al exterior.
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Nudging: A new social behavior described in Corydoras aeneus cory catfish

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Riley, R. J. (2019). Keeping it together: the effect of familiarity, personality, and active interactions on group coordination. Doctoral thesis, Department of Zoology, University of Cambridge. Doi: 10.17863/CAM.35774

https://www.repository.cam.ac.uk/handle/1810/288486
https://doi.org/10.17863/CAM.35774
ABSTRACT
Group coordination is a universal feature of social life. Animals form social groups for a variety of reasons, including predator evasion and more efficient foraging, and individuals living in social groups must coordinate their activities in order for groups to function. Consequently, the factors that facilitate or impede group coordination are of great interest in understanding the lives of social animals. Familiarity between individuals has well-documented effects on group coordination, with familiar groups outperforming unfamiliar ones in predator evasion, foraging, and cohesion. Individuals also generally prefer to coordinate with familiar conspecifics over unfamiliar ones. Despite these advantages, the mechanisms through which familiarity might aid group coordination are poorly understood. Similarly, the individual personalities of group members have well-documented effects on group performance: bold individuals are more likely to be ‘leaders’ and determine the direction of group movements, and groups comprised of individuals of differing personalities outperform groups of all bold or all shy individuals. While the effect of individual personalities on group behaviour has been recorded extensively, the ways in which individuals affect each other’s behaviour are still poorly documented. In particular, active interactions where one individual can directly affect the behaviour of others have received limited attention, as it is difficult to distinguish such actions from passive effects. I used two systems to investigate how individual behaviours can lead to group coordination. In three-spined sticklebacks (), well-established boldness assays allowed me to assess the effects of personality and familiarity on 1) coordination between pairs of fish; I found that individuals in unfamiliar pairs exhibited coordination patterns consistent with their individual personalities, with bold individuals more likely to leave cover independently, while in familiar pairs, individuals behaved in ways seemingly unrelated to their boldness scores. I also investigated how personality and familiarity affect 2) group coordination and individual performance in a problem-solving paradigm. I found that familiarity, relative individual personality, and group mean personality interact to affect individual foraging success, and that group cohesion was affected by the interaction of group familiarity and group mean personality. These results suggest that individual characteristics can impact the behaviour of groups, and that the characteristics of an individual’s group can in turn affect an individual’s behaviour and success. In the Bronze Cory catfish (), I described a novel tactile interaction style termed ‘nudging’ that individuals use during group coordination. I investigated 3) the effect of familiarity on nudging and coordination in pairs and triplets. These results show that nudging can be used to overcome the disadvantages of familiarity, which has important implications for how communication can underlie group coordination in the absence of familiarity. I then investigated how 4) nudging affects group coordination following a flight response to a potential threat. I demonstrated that nudging leads to a higher likelihood of group cohesion and longer group flight times. This shows how active interactions can mediate group responses and affect the ecologically relevant scenario of predator evasion. Finally, I investigated 5) the development of this nudging behaviour. My results show that Bronze Cory catfish larvae develop toleration for tactile stimulation with age alongside their propensity to nudge conspecifics. This suggests that Bronze Cory catfish larvae require social feedback to develop appropriate responses to nudges from conspecifics and supports the important role of nudging in Bronze Cory catfish sociality. The presence of active interactions in the Bronze Cory catfish` modifies the way that social behaviour manifests in this species and has great potential for further questions about social behaviour and group functioning.
  • Keywords: Social behaviour, familiarity, group coordination
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Developmental and functional analysis of scutes in the armored catfish Corydoras aeneus,

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Developmental and functional analysis of scutes in the armored catfish Corydoras aeneus

Be careful : Not a science news, but a Thesis !

Author : Emily Volk
Source : Undergraduate Honors These , University of Colorado, Boulder, April 4 2019
HTML : https://scholar.colorado.edu/honr_theses/1832/
PDF : https://scholar.colorado.edu/cgi/viewco ... onr_theses
Abstract wrote: Fish scales are specialized biological structures of current interest in innovative materials design because of the combination of protective function, flexibility, and light weight they offer. This study presents a developmental and functional investigation of a particular fish scale structure, the scutes (bony external plates) of the armored Bronze Corydoras Catfish (Corydoras aeneus). Scutes in this model fish species were analyzed via three complementary approaches. First, scutes were documented throughout fish development via high-quality microscope images. These images were subsequently used to inform fabrication of synthetic models to characterize the relationship between scute overlap and overall bending stiffness of scute assemblies. These models indicated that scute overlap resulted in a 318% increase in bending stiffness. My study also presents insight into how increased bending stiffness could influence the swimming strategy of live larval C. aeneus. By synthesizing the insight from these developmental and functional investigations of the scutes of C. aeneus, my study aims to contribute to a better functional understanding of the evolutionary pathway of C. aeneus as well as inform fabrication of future innovative designs utilizing the unique structure and dynamics of scute assemblies.
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Revision of the Genus Mastiglanis (Bockmann, 1944)

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Modertor's note, Mastiglanis sp(1) was described in July 2020 and is now . (link here: viewtopic.php?f=14&t=49301)

Fuster, D. R. F. (2019). Revisión taxonómica del género Mastiglanis (Bockmann, 1994)(Siluriformes: Heptapteridae) en Perú. Thesis for a Professional Degree in Biology, Universidad Nacional Mayor de San Marcos, Universidad del Perú, Decana de América. Escuela Profesional de Ciencias Biológicas.

http://cybertesis.unmsm.edu.pe/handle/cybertesis/10514
PDF: http://cybertesis.unmsm.edu.pe/bitstrea ... sAllowed=y

NOTE: I've added the two undescribed fish to the CLOG as and .
ABSTRACT
is a monotypic genus, with the type species M. asopos, belonging to Heptapteridae. This freshwater species is widely distributed along the Amazon and Orinoco River basins. In this research, a taxonomic review of specimens collected from the Putumayo and Nanay River, Amazon rivers basin in Peru. The morphological analysis was carried out taking morphometric (36 measurements) and meristic (20 counts) data, with the help of a digital caliper and stereo microscope; some osteological counts and descriptions were made of clear and stained material. This study revealed two new species of Mastiglanis. The two new species of Mastiglanis differ from M. asopos by having short snout. Mastiglanis sp1 is differentiated from its congeners by having eight branched anal fin rays and a large pelvic fin large; additionally, Mastiglanis sp1 is differentiated from M. asopos by having more number of vertebrae, epibranchial spines, ceratobranchial spines, by having a short process in the sinfisial region of the premaxila, thin body, broad interorbital space, big eyes, head tall, and thin. Mastiglanis sp2 differs from all its congeners by having a lower caudal peduncle; additionally, it differs from M. asopos by having a larger eye diameter; and from Mastiglanis sp1 by having more branched anal fin rays, short pelvic-fin, broader head, smaller interorbital space and smaller posterior nostrils space. The two new species are distributed in the Yaguas River, tributary of the Putumayo River; and in the Nanay River tributaries from the Amazon basin, from the Loreto Department, Peru.
  • Keywords: small catfish, morphology, freshwater, Peruvian Amazon.
RESUMEN
es un género monotípico, con la especie tipo M. asopos, que pertenece a Heptapteridae, esta especie de agua dulce se encuentra ampliamente distribuida a lo largo de los ríos Amazonas y Orinoco. En la investigación se realizó una revisión taxonómica de ejemplares colectados en las cuencas del Putumayo y Amazonas en Perú. El análisis morfológico fue realizado considerando datos morfométricos (36 medidas) y merísticos (20 conteos), con ayuda de un calibrador digital y estéreo microscopio; algunos conteos y descripciones osteológicas fueron realizados de material diafanizado. En este estudio se revelan dos nuevas especies de Mastiglanis. Las dos especies nuevas de Mastiglanis se diferencian de M. asopos por tener el hocico corto. Mastiglanis sp1 se diferencia de sus congéneres por presentar 8 radios ramificados en la aleta anal, aleta pélvica grande, adicionalmente Mastiglanis sp1 es diferenciado de M. asopos por presentar mayor número de vertebras, espinas epibranquiales, espinas ceratobranquiales, por tener el proceso en la región sinfisial de la premaxila corto, cuerpo delgado, espacio interorbital amplio, ojo grande, cabeza alta y delgada. Mastiglanis sp2, se diferencia de todos sus congéneres por presentar el pedúnculo caudal bajo; adicionalmente se diferencia de M. asopos por tener un mayor diámetro del ojo; y de Mastiglanis sp1 por tener más radios anales ramificados, aleta pélvica corta, cabeza ancha, espacio interorbital menor y el espacio entre las narinas posteriores menores. Las dos nuevas especies se encuentran distribuidas en los ríos Yaguas, tributario del rio Putumayo; y en el río Nanay tributario de la cuenca del Amazonas, en el departamento de Loreto, Perú.
  • Palabras claves: bagres menudos, morfología, agua dulce, Amazonia Peruana
Attachments
Figure 9. Distribution map of Mastiglanis asopos (white triangles), Mastiglanis sp.1 (red circles) and Mastiglanis sp.2 (yellow star) in the neotropical region. The star symbol represents the type locality of each species. Each symbol can represent more than one lot.
Figure 9. Distribution map of Mastiglanis asopos (white triangles), Mastiglanis sp.1 (red circles) and Mastiglanis sp.2 (yellow star) in the neotropical region. The star symbol represents the type locality of each species. Each symbol can represent more than one lot.
Mastiglanis sp.1, new species, MUSM 66612, 49.1 mm LE
Mastiglanis sp.1, new species, MUSM 66612, 49.1 mm LE
Mastiglanis sp.2, MUSM 55055, Holotype, 43.7 mm LE
Mastiglanis sp.2, MUSM 55055, Holotype, 43.7 mm LE
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Two new Hypostomus species from the Rio Maranhao and Rio Sao Bartolomeu, Central Brazil

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Moderator's note: these two species are described now: viewtopic.php?t=50042
Hypostomus sp. nov. A =
Hypostomus sp. nov. B =



SOARES, Yan Felipe Figueira. (2019). Description of new species of Hypostomus (Siluriformes: Loricariidae) for Central Brazil. Dissertation (Master in Zoology). University of Brasilia, Brasilia.

https://repositorio.unb.br/handle/10482/35787
PDF: https://repositorio.unb.br/bitstream/10 ... Soares.pdf
ABSTRACT:
We described two new species of from central Brazil based on morphological data sets, with lineages previously identified in genomic studies. A machine learning classification procedure (random forest) was used to investigate the morphological variation and to identify species diagnostic characters. The new species Hypostomus sp. nov. A is characterized by the reduced size, dark spots under a light background, deeper caudal peduncle, smaller first ray of the pectoral fin and smaller base of the dorsal fin when compared to its congeners. Hypostomus sp. nov. A is known for the headwaters of the river Maranhão, upper Tocantins river basin, Federal District, Brazil. The second new species Hypostomus sp. nov. B is characterized by dark spots under a light background, absence of plaques in the abdomen, smaller first ray of the pelvic fin, smaller first ray of the pectoral fin and smaller body size. Hypostomus sp. nov. B is known for the headwaters of the São Bartolomeu river, upper Paraná river basin, Federal District Brazil.
RESUMO:
Descrevemos duas novas espécies de do Brasil central que foram identificadas previamente em estudos genômicos, promovendo uma descrição com a diagnose baseada em conjuntos de dados morfológicos. Foi utilizado um procedimento de classificação de aprendizado de máquina (random forest) para investigar a variação morfológica e identificar caracteres diagnósticos para as espécies. A nova espécie Hypostomus sp. nov. A é caracterizada pelo tamanho reduzido, pontos escuros sob um fundo claro, altura do pedúnculo caudal maior, primeiro raio da nadadeira peitoral menor e base da nadadeira dorsal menor, quando comparada aos seus congêneres. Hypostomus sp. nov. A é conhecida das cabeceiras do rio Maranhão, bacia do alto rio Tocantins, Distrito Federal, Brasil. A segunda nova espécie Hypostomus sp. nov. B é caracterizada por possuir pontos escuros sob um fundo claro, ausência de placas na região do abdômen, primeiro raio da nadadeira pélvica menor, primeiro raio da nadadeira peitoral menor, tamanho corporal menor. Hypostomus sp. nov. B é conhecida das cabeceiras do rio São Bartolomeu, bacia do alto rio Paraná, Distrito Federal Brasil.
Attachments
Distribution of Hypostomus sp. nov. A (blue square) and Hypostomus sp. nov. B (pink rhombus). Triangle represents the type locale. The acronyms AP, AT and MSF mean Alto Parana, Alto Tocantins and Mid São Francisco, respectively
Distribution of Hypostomus sp. nov. A (blue square) and Hypostomus sp. nov. B (pink rhombus). Triangle represents the type locale. The acronyms AP, AT and MSF mean Alto Parana, Alto Tocantins and Mid São Francisco, respectively
Hypostomus sp. nov. A, CIUNB 1490, paratype, upper Tocantins river basin
Hypostomus sp. nov. A, CIUNB 1490, paratype, upper Tocantins river basin
Hypostomus sp. Nov B, Taquara Stream, Upper Parana River Basin
Hypostomus sp. Nov B, Taquara Stream, Upper Parana River Basin
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Re: The Dissertations Sticky

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Martine, G. (2019). Distribuição do ictioplâncton em diferentes micro-habitats do médio Rio Uruguai, Brasil. Dissertação de Mestrado, Programa de Pós Graduação em Ambiente e Tecnologias Sustentáveis da Universidade Federal da Fronteira Sul.

https://rd.uffs.edu.br/handle/prefix/3098
PDF: https://rd.uffs.edu.br/bitstream/prefix ... ARTINE.pdf
ABSTRACT
Research related to ichthyoplankton provides relevant information about its initial development, but for the Uruguay River basin, little is known about which environments are preferred by fish larvae during the early stages of their life cycle. From this, the objective of this work was to evaluate five microhabitats in three sample stations in the middle Uruguay River, located in the municipalities of Porto Mauá, Porto Vera Cruz and São Nicolau, RS, respectively. Monthly collections were carried out at night, from November 2017 to January 2018, totaling 180 samplings. The spatial distribution of the sampling stations lies in a stretch of approximately 150 km. Each sampling station presents four microhabitats in the Uruguay River: rapids, island, margin and well; and one near the mouth of a tributary river: Santa Rosa River (PM), Amandaú River (PVC) and Rio Piratinim (SN). At all points, active collections were carried out from trawls with a mesh of 500 μm conical-cylindrical plankton. The variables: transparency, velocity, temperature, dissolved oxygen, electrical conductivity, pH, depth and river level were measured monthly. The samples collected were fixed in 4% formaldehyde, sorted and identified at the species level. The larval stages considered were: vitelline larval (LV), pre-flexion larval (LP), larval flexion (LF) and post-flexion larval (OLP). 1,523 larvae were captured, four orders, 14 families, 27 genera and 19 species. Of these, 92.12% belong to the Siluriform order, with the Pimelodidae family (89.43%) being the most abundant, being (50.10%), (15.30%) and (8.14%). Migratory fish species were also captured: the Characiformes and and the Siluriformes , , and . There was no statistically significant difference in larval distribution in the collection months (p> 0.05). Regarding the total larvae / 10m3 and the sampling stations, PVC had the highest densities (p <0.05). As for the larval stages and the sampling stations, LV presented the highest density in the PM station (p <0.05). For the larval stages of pre-flexion, flexion and post-flexion, there was a significant statistical difference (p <0.05), in which PVC presented the highest densities. The CCA revealed the most grouped and segregated wells and rapids of the island, margin and tributary (P <0.05) microhabitats. The CCA1 showed that water velocity (p <0.05), depth (p <0.05) and water transparency (p <0.05) were the most important factors for the distribution of larval stages. The LV stage (p <0.05) was positively correlated with water velocity and the greatest depth of the environment. Post-flexion larvae (p <0.05) were mainly related to greater transparency and inversely related to water depth and velocity. The NMDS revealed clear spatial segregation between the channel and island microhabitats of the margin and the tributary. According to the results, it is concluded that the PVC sampling station had the highest densities of fish larvae, and the micro-habitat Ilha represents the site of higher incidence of total larvae, which characterizes it as a nursery of fish larvae in initial stages, mainly Siluriformes.
Keywords: Reproduction of fish. Eggs and larvae. Spatial distribution. Nursery areas. Medium river Uruguay.
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Bacterial and fungal symbionts in the guts of woodlice and Panaque nigrolineatus

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Marden, Caroline Louise. (2019). Characterisation of the microbial communities in the gastrointestinal tract of wood-eating organisms. Doctoral dissertation, University of Portsmouth.

https://ethos.bl.uk/OrderDetails.do?uin ... hos.800220
https://researchportal.port.ac.uk/porta ... d395).html
PDF: https://researchportal.port.ac.uk/porta ... r_viva.pdf
ABSTRACT
Wood recycling is key to biogeochemical cycling and largely driven by microorganisms, with bacteria and fungi naturally coexisting together in the environment. Terrestrial isopods Oniscus asellus and Porcellio scaber have adaptations to enable them to colonise diverse terrestrial environments and scavenge on dead and decaying organic matter that is rich in cellulose. The Amazonian catfish, have physiological adaptions enabling the scraping and consumption of wood, facilitating a detritivorous dietary strategy. Substrates high in lignocellulose are difficult to degrade and as yet, it is unclear whether these organisms obtain any direct nutritional benefits from ingestion and degradation of lignocellulose. However, there are numerous systems that rely on microbial symbioses to provide energy and other nutritional benefits for host organisms via lignocellulose decomposition. Whilst previous studies on the microbial communities of O. asellus, P. scaber and P. nigrolineatus, have focused upon the bacterial populations, the presence and role of fungi in lignocellulose degradation has not yet been examined. These studies describe the bacterial and fungal communities within the gastrointestinal tracts using next generation sequencing. The hepatopancreas of O. asellus and P. scaber was predominantly colonised by one bacterial species and had more fungal diversity. The hindgut was colonised bymore diverse bacterial and fungal communities. Due to the woodlouse inhabiting diverse environments, including those with heavy metal pollution, culture methods were used to detect antimicrobial resistance in the gastrointestinal tract of woodlice. The effects of diet on enteric fungal populations were examined in each gastrointestinal tract region of P. nigrolineatus and fungal species were found to vary in different regions of the gastrointestinal tract as a function of diet. This is the first study to investigate the bacterial and fungal communities within the hepatopancreas and hindgut from two species of woodlice, using the same individual woodlouse, using next generation sequencing. This is the first study to detect fungi in the digestive tract of any woodlice. This study is the first to examine the fungal community in a xylivorous fish and results support the hypothesis that diet influences fungal distribution and diversity within the gastrointestinal tract of P. nigrolineatus. This study provides new insights into the microbial communities that may have a symbiotic role involved in wood degradation in the GI tracts of woodeating organisms. This study also highlights the need for further research into fungi inhabiting many diverse environments to give more complete and balanced information about the absence and presence of microorganisms.
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Larviculture of acari bread Hypancistrus sp. L333

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REIS, Ryuller Gama Abreu Reis. (2020). Larviculture of acari bread Hypancistrus sp. L333 (Siluriformes Locariidae): food management and stocking density. Dissertation (Master in Aquaculture and Tropical Aquatic Resources) - Federal Rural University of the Amazon, Belém, 2020.

http://repositorio.ufra.edu.br/jspui/ha ... 456789/961
Abstract:
Acari Pão (Hypancistrus sp.) is an Amazonian species, endemic from the Xingu River, with an important potential for ornamental aquaculture, because its colors and the high value in the market of ornamental aquatic organisms. However, there is little scientific information about the ideal breeding conditions for the species, such as reproduction, larviculture, feed management and nutrition. In this context, one of the major gaps to the captive production of ornamental aquatic organisms is the lack of knowledge about the requirements and food management of the species. The present study aimed to evaluate some managements in the intensive larviculture of Acari Pão L333, more specifically to determine the amount of live food (Artemia nauplii), the stocking density and the time for the food transition from live food to the formulated diet (weaning). The first study was divided into two experiments, where the objective were to evaluate four initial prey concentrations (T100 -100, T200 - 200, T300 - 300 and T400 - 400 nauplii / larvae / day), with amount of prey doubling every six days of the experiment. The second experiment was carried out to determine the ideal stocking density (1, 5, 10, 15 larvae / L) for the species. In the second study, the best time for the weaning was evaluated, in which the substitution was tested after 5, 10, 15 and 20 days of live food supplied. In addition, two treatments were added, in which the larvae received the live food and the formulated diet throughout the experimental period. The results showed that for the larviculture of the species the initial prey concentration of 400 artemia nauplii / larvae / day and the stocking density of 5 larvae / L are recommended. The best period for the weaning was after five days of live food supplied; however, the results of survival with the exclusive use of the formulated diet emerges as a great possibility for future studies on the topic.
  • Keywords: Acari bread L333 - Larviculture, Ornamental fish
    Acari bread L333 - Food, Siluriformes Lori, Hypancistrus sp., Ornamental fish culture, Ornamental fish species
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Structure of the rheophilic ichthyofauna of the Xingu River

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COMMENT: This thesis has some great maps of the area, and also many good photographs of the habitats present along the Xingu. Many diverse rocky and sandy surfaces are shown where loricariids were collected, any of which would probably look neat in an aquarium

Gonçalves, A. P. (2020). Structure of the rheophilic ichthyofauna of the Xingu river, Brazilian Amazon: environmental, spatial and temporal effects on the species distribution pattern. Doctoral Thesis, Biologia de Água Doce e Pesca Interior - BADPI.

Gonçalves, A. P. (2020). Estrutura da ictiofauna reofílica do rio Xingu, Amazônia Brasileira: efeitos ambientais, espaciais e temporais no padrão de distribuição das espécies. Tese, Doutora. Biologia de Água Doce e Pesca Interior - BADPI Doutorado - BADPI.

https://repositorio.inpa.gov.br/handle/1/13016
https://repositorio.inpa.gov.br/bitstre ... cavels.pdf
ABSTRACT
Rapids and waterfalls are environments that have extreme and peculiar environmental characteristics when compared to other river stretches. These sites harbor fish species with unique ecological characteristics, with remarkable morphological and behavioral specializations related to the life in structurally complex environments with fast and turbulent waters. In this study we evaluated the structure of the ichthyofauna in the rapids of Xingu River, aiming to a better understanding of the fish assemblage composition and its spatial and temporal variations. We recorded 160 fish species in the rapids, belonging to 97 genera, 25 families and seven orders. Characiformes presented the highest number of families, and Siluriformes the highest number of species. Fifty-two species are endemic to the Xingu River, 11 species are officially considered under some degree of extinction risk, and not all species are protected by the large mosaic of conservation units in the Xingu River basin. The stretch corresponding to the Volta Grande do Xingu harbors the highest diversity of rheophilic fishes along the analyzed stretch of the river, and some species apparently occur only in that stretch. The Volta Grande do Xingu is one of the largest continuous rapids in the world, but the structure of the fish assemblages of this region varies both seasonaly and regarding local habitat characteristics. The largest variations were observed between the main channel rapids of the Xingu and Bacajá rivers, and between the flooding period compared to the receding and dought periods. Although some species occurred in just a few sites or were more abundant in some periods of the hydrologic cycle, several species occurred in all sampling sites and periods, highlighting the possible role of habitat connectivity along the rapids continuum. However, additional analyses of the distribution and abundance of Loricariidae species in Volta Grande evidenced the role of spatial factors acting at different distance scales, which together with the local structure of microhabitats are essential for the maintenance of the loricariid diversity. Food availability did not have a major influence on the structure of Loricariid assemblages, apparently due to the high availability of food items from epilithic and benthic macroinvertebrates. Despite the biological importance of waterfalls and rapids environments, especially those of Volta Grande, a hydroelectric megadam is installed in the region and a huge gold mining project is being licensed, threatening one of the world's most spectacular river rapids.
RESUMO
As corredeiras e cachoeiras são ambientes que apresentam características ambientais extremas e diferentes da maior parte do curso dos rios. Esses locais abrigam espécies de peixes com características ecológicas peculiares, com especializações morfológicas e comportamentais relacionados à vida em ambientes estruturalmente complexos e com águas rápidas e turbulentas. Neste estudo avaliamos a estrutura da ictiofauna associada aos ambientes de corredeiras do rio Xingu, buscando um melhor entendimento da composição das assembleias de peixes e suas variações espaciais e temporais. Foram registradas 160 espécies de peixes abrigando as corredeiras do rio Xingu, pertencentes a 97 gêneros, 25 famílias e sete ordens. Characiformes apresentou o maior número de famílias e Siluriformes o maior número de espécies. Cinquenta e duas espécies são endêmicas do rio Xingu, 11 espécies são oficialmente consideradas sob algum grau de ameaça de extinção, e nem todas as espécies estão protegidas pelo grande mosaico de unidades de conservação presentes na bacia do rio Xingu. O trecho da Volta Grande do rio Xingu apresenta a maior diversidade de espécies de peixes reofílicos, e algumas espécies ocorrem apenas naquele trecho. A Volta Grande é um dos maiores contínuos de corredeiras do mundo, mas a estrutura das assembleias de peixes dessa região apresenta diferenças em relação aos períodos sazonais e em função das características locais dos sítios de amostragem. As maiores variações foram observada entre as corredeiras do canal principal do rio Xingu e as corredeiras do rio Bacajá, e entre os períodos de enchente em relação à vazante e seca. Embora algumas espécies tenham ocorrido em apenas alguns sítios ou tenham sido mais abundantes em alguns períodos, a Volta Grande apresenta um conjunto de espécies que ocorrem em todos os sítios e períodos, evidenciando o possível papel da conectividade de hábitats ao longo do contínuo de corredeiras. Uma análise mais aprofundada da distribuição e abundância de espécies de Loricariidae na Volta Grande demonstrou que fatores espaciais em diferentes escalas de distância, bem como a estrutura local de micro-hábitats são essenciais para a manutenção das espécies dessa família. Disponibilidade de alimento não apresentou grande influência na estruturação das assembleias de Loricariídeos, aparentemente devido à alta disponibilidade de itens alimentares do epilíton e de macroinvertebrados bentônicos. Apesar da importância biológica dos ambientes de cachoeiras e corredeiras, em especial as da Volta Grande, um megaprojeto hidrelétrico está sendo finalizado nessa região e há projetos de mineração de ouro sendo licenciados, colocando em risco uma das áreas de corredeiras mais excepcionais do mundo.
Attachments
Xingu rocks.png
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Morphological variation of Transancistrus santarosensis

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Valverde Tobar, C. L. (2020). Morphological aspects of Transancistrus santarosensis (Loricariidae) present in the trans-Andean basins of the Andes Mountains of Ecuador. Thesis, University of Guayaquil.

http://repositorio.ug.edu.ec/handle/redug/48681
PDF: http://repositorio.ug.edu.ec/bitstream/ ... 0%20CD.pdf
ABSTRACT
Geometric morphometry is the application of statistical analysis about the variation in the real shape of organisms and can be used to differentiate populations or species. This study focuses on comparing the morphological and bone variations of in different locations in the western part of the Andes Mountains of Ecuador. The samples of T. santarosensis were obtained in the basins of the Caluma, BuluBulu, Tenguel and Santa Rosa rivers in a range of 100 to 280 masl. A total of 65 specimens of T. santarosensis were analyzed and the size ranges ranged from 5.1 to 12.5 mm in total length. Regarding the consensus form of the specimens from each locality, significant differences p <0.0005 were observed. The northern specimens presented a reduction between the anal fin and the caudal fin, as well as between the dorsal and adipose fins; in addition, a reduction in the abdomen was observed in the southern specimens. The specimens from the four localities showed no differences in the morphology of the cephalic plates. The morphology of the plates is characteristic at the gender level since the same morphological characters are observed in T. aequinoctialis.
  • Keywords: Geometric morphometry, Morphological variations, Consensus shape, Cephalic plates, Alizarin red.
Valverde Tobar, C. L. (2020). Aspectos morfológicos de Transancistrus santarosensis (Loricariidae) presentes en las cuencas transandinas de la Cordillera de los Andes de Ecuador. Tesis, Universidad de Guayaquil.
RESUMEN
La morfometría geométrica es la aplicación de análisis estadísticos acerca de la variación de la forma real de los organismos y puede ser utilizada para diferenciar poblaciones o especies. Este estudio se enfoca en comparar las variaciones morfológicas y óseos de en distintas localidades de la zona occidental de la Cordillera de los Andes de Ecuador. Las muestras de T. santarosensis fueron obtenidos en las cuencas de los Ríos Caluma, BuluBulu, Tenguel y Santa Rosa en un rango de 100 a 280 msnm. Se analizaron en total 65 especímenes de T. santarosensis y los rangos de tallas oscilaron entre 5.1 a 12,5 mm de longitud total. En cuanto a la forma consenso de los especímenes de cada localidad, se observó diferencias significativas p < 0.0005. Los especímenes del norte presentaron una reducción entre la aleta anal y la aleta caudal, así mismo entre la aleta dorsal y la adiposa; además se observó una reducción en el abdomen en los especímenes del sur. Los especímenes de las cuatro localidades no mostraron diferencias en la morfología de las placas cefálicas. L a morfología de las placas es característica a nivel de género ya que, en T. aequinoctialis se observan los mismos caracteres morfológicos.
  • PALABRAS CLAVES:
    Morfometría geométrica, variaciones morfológicas, forma
    consenso, placas cefálicas, rojo alizarina
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Noodling kills

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Dwyer, T. W. (2020). Human Mortality Rate of Noodling Catfish in Oklahoma (Doctoral dissertation, University of Central Oklahoma).

https://search.proquest.com/docview/245 ... nview=true
Noodling is a legal method of catching certain species of fish in the state of Oklahoma and in other states in the South and Midwest. Unlike other forms of angling, noodling requires that the angler be in the same physical aquatic environment as the targeted animal without the aid of equipment such as rods, reels, and nets. The peril of this method of fishing is apparent in the numerous injuries reported annually in Oklahoma. In addition, anglers are sometimes killed while noodling. Other forms of fishing, both sport and commercial, are much more common and have better documentation and regulations pertaining to their dangers. For example, commercial fishing in the Pacific Northwest carries great risk associated with the occupation; long hours at sea, hazardous environments, sleep deprivation, and heavy equipment account for the lives of commercial fisherman each season. Prior research has shown that some commercial fishing occupations are, per capita, among the deadliest jobs in the world (Davis, 2012). Through statistical analysis and case studies of noodling deaths, this research sought to determine if, in comparison to the well-documented deadly occupation of commercial fishing, noodling ranks as one of the most hazardous types of fishing on the planet. While far fewer people participate in hand-fishing, the data indicate that, per capita, it is extremely dangerous when compared to other types of fishing. Thus, the regulating authorities should educate participants of the risks, and perhaps formulate additional policies to prevent the further unnecessary loss of life.
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Feeding habits and morphological relationships of Loricariids from the Volta Grande region of Rio Xingu

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Jesus, T. S. (2020). Feeding habits and morphological relationships of species of Loricariidae (Actinopterygii: Siluriformes) from the Volta Grande region of the Xingu River, Pará, Brazil. Dissertation, Masters of Biological Sciences, National Institute of Amazonian Research.

Jesus, T. S. (2020). Hábitos alimentares e relações morfológicas de espécies de Loricariidae (Actinopterygii: Siluriformes) da região da Volta Grande do rio Xingu, Pará, Brasil. Dissertação, Mestre em Ciências Biológicas, Instituto Nacional de Pesquisas da Amazônia.

https://repositorio.inpa.gov.br/handle/1/36384
PDF: https://repositorio.inpa.gov.br/bitstre ... 0Jesus.pdf
The relationship between morphological attributes and foraging habits was analyzed in 13 species of Loricariidae from Volta Grande do Xingu. We investigated the degree of similarity of morphological characteristics related to obtaining and processing food; and whether the composition of the species' diet is associated with the morphological features. Field collections were carried out between the years 2012 and 2013, including the receding water (July) and low water (September, October, and November) periods in the Volta Grande do Xingu region. The fish capture was carried out throughout direct search, through diving sessions, gillnets, and nets. A total of 185 individuals were used for morphological and diet analysis. 21 morphological attributes associated with food capture and assimilation were selected and analyzed by ordering methods, (Principal coordinate analysis (PCoA) and grouping (Cluster)), which allowed the visualization of morphological patterns between the species of the subfamilies Hypoptopomatinae, Hypostominae and Loricariinae. The analysis of the species diet indicated a broad diet spectrum, with 33 types of alimentary items identified. The Alimentary Importance Index (IAi) was used to identify the main alimentary items for each species, and according to the results, the species were classified into five trophic categories: detritivore, algivore, carnivore, omnivore, and xylophage. The non-metric multidimensional scaling (nMDS) and Cluster identified different trophic patterns and the use of alimentary resources by the species. The correlations between morphology and diet were tested by the Mantel test and a correlation was found between them, indicating that the morphological patterns are related to the feeding habits of the analyzed species, meaning that, the more different the morphologies, the more distinct the diets. Overall, our results show that the diversity of identified alimentary items demonstrated that diet among loricariids can be quite distinct, the importance of rapids environments for the trophic dynamics of these species and that the morphological variety of the digestive tract among species of Loricariidae may have allowed the success in the exploration of different food resources.
As relações entre atributos morfológicos e hábitos alimentares foram analisadas em 13 espécies de Loricariidae da Volta Grande do rio Xingu. Foi investigado o grau de similaridade de características morfológicas relacionadas à obtenção e processamento do alimento, e se a composição da dieta das espécies está associada às características morfológicas mensuradas. As coletas foram realizadas entre os anos de 2012 e 2013 compreendendo os períodos de vazante (julho) e seca (setembro, outubro e novembro) na região da Volta Grande do Xingu. A captura dos peixes foi realizada através da busca direta, por meio de sessões de mergulho, redes de emalhar e tarrafas. Um total de 185 exemplares foram utilizados para análises morfológicas e de dieta. Foram analisados 21 atributos morfológicos associados à captura e assimilação de alimentos e analisados por métodos de ordenação (Análise de coordenadas principais (PCoA) e agrupamento (Cluster)), o que permitiu a comparação de padrões morfológicos entre as espécies das subfamílias Hypoptopomatinae, Hypostominae e Loricariinae. A análise da dieta das espécies indicou um amplo espectro alimentar, tendo sido identificados 33 tipos de itens alimentares. O Índice de Importância Alimentar (IAi) foi utilizado para identificar os principais itens consumidos por cada espécie, e de acordo com os resultados, as espécies foram classificadas em cinco categorias tróficas: detritívora, algívora, carnívora, onívora e xilófaga. As análises de escalonamento multidimensional não-métrico (nMDS) e de agrupamento identificaram diferentes padrões tróficos e de uso dos recursos alimentares pelas espécies. As correlações entre morfologia e dieta foram testadas pelo teste de Mantel e constatada correlação entre elas, indicando que os padrões morfológicos são relacionados aos hábitos alimentares das espécies analisadas, ou seja, quanto mais diferentes as morfologias, mais distintas são as dietas. Finalmente, a diversidade de itens alimentares identificados demonstra a importância dos ambientes de corredeira para a dinâmica trófica dessas espécies e que a variedade morfológica do trato digestório entre as espécies de Loricariidae pode ter permitido o sucesso na exploração de diferentes recursos alimentares.
Attachments
Figura 2 - A) Ancistrus ranunculus (95,0 mm); B) Baryancistrus xanthellus (86,2 mm); C) Panaque armbrusteri (182,8 mm); D) Parancistrus nudiventris (152 mm); E) Peckoltia vittata (88,6 mm); F) Pseudancistrus asurini (121,9 mm); G) Scobinancistrus pariolispos (84,1 mm); H) Spectracanthicus zuanoni (92,2 mm); I) Limatulichthys griseus (134,8 mm); J) Loricaria birindellii (231,9 mm); K) Pseudoloricaria laeviuscula (180,2 mm); L) Spatuloricaria tuira (134,7 mm); M) Hypoptopoma inexspectatum (88,5 mm). Fotos: A, I &amp; K – Taís de Jesus; B – Renildo R. Oliveira; C, D, E, F, H, M – Leandro M. Sousa; J &amp; L – Mark S. Pérez.
Figura 2 - A) Ancistrus ranunculus (95,0 mm); B) Baryancistrus xanthellus (86,2 mm); C) Panaque armbrusteri (182,8 mm); D) Parancistrus nudiventris (152 mm); E) Peckoltia vittata (88,6 mm); F) Pseudancistrus asurini (121,9 mm); G) Scobinancistrus pariolispos (84,1 mm); H) Spectracanthicus zuanoni (92,2 mm); I) Limatulichthys griseus (134,8 mm); J) Loricaria birindellii (231,9 mm); K) Pseudoloricaria laeviuscula (180,2 mm); L) Spatuloricaria tuira (134,7 mm); M) Hypoptopoma inexspectatum (88,5 mm). Fotos: A, I & K – Taís de Jesus; B – Renildo R. Oliveira; C, D, E, F, H, M – Leandro M. Sousa; J & L – Mark S. Pérez.
Figure 14 - Heat map generated from the cluster analysis (Cluster) for the composition of the diet of the 13 species of Loricariidae from Volta Grande on the Xingu River: P. nudiventris, A. ranunculus, P. vittata, H. inexspectatum, B. xanthellus, S. zuanoni (detritivores and algivores), P. armbrusteri (xylophage); P. laeviuscula, L. birindellii, L. griseus, S. pariolispos, S. tuira (carnivores and omnivores). The different shades indicate the relative importance of each food item in the species' diet.
Figure 14 - Heat map generated from the cluster analysis (Cluster) for the composition of the diet of the 13 species of Loricariidae from Volta Grande on the Xingu River: P. nudiventris, A. ranunculus, P. vittata, H. inexspectatum, B. xanthellus, S. zuanoni (detritivores and algivores), P. armbrusteri (xylophage); P. laeviuscula, L. birindellii, L. griseus, S. pariolispos, S. tuira (carnivores and omnivores). The different shades indicate the relative importance of each food item in the species' diet.
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Re: The Dissertations Sticky

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Almeida, R. B. D. 2019. Delimitação de espécies e filogeografia molecular comparada para Isbrueckerichthys (Siluriformes: Loricariidae): a influência de captura de rios na história evolutiva.

https://www.acervodigital.ufpr.br/handle/1884/71311
ABSTRACT
The evolution and distribution of Neotropical fish are strictly linked to geologic events of dispersion. An important mechanism that promote the species dispersion and the evolution of fishes is the event known as headwaters capture or river capture. This kind of geological events interconnects adjacent basins and isolate the ones that were previously connected, promoting at same time the isolation (vicariance) and the dispersion (geodispersion) of fish species. In Brazilian south/southeast regions geographical alterations promoted events of river capture and faunal interchange between coastal drainages and higher of the Brazilian crystalline shield. The genus (Loricariidae: Neoplecostominae) is endemic of Brazilian south/southeast, making them a key group to understand the evolutive effects of river capture events in these regions. The aim of this work was to infer patterns of geographic distribution and genetic diversity of Isbrueckerichthys in bordering regions of the Ponta Grossa Arch for the Ribeira de Iguape and Tibagi rivers basins. Also, to prospect the evolutionary history associated with geologic events of river capture in the group diversification. For this purpose, were performed molecular identification and species delimitation analysis of DNA barcoding and GMYC using cytochrome c oxidase subunit I. For the populational investigations were performed Analysis of Molecular Variance and diversity, phylogenetic and phylogeographical inferences, molecular clock, besides the population genetics index, as ΦST, haplotipic diversity, nucleotic diversity, haplotipic diversity, haplotipic network, Mantel Test and bayesian analysis of structuration. I. calvus and I. saxicola behaves as a single taxonomic category both in relation to K2P genetic divergence (1,32% ±0,022%), as in GMYC and phylogenetic inferences. Populational analysis shown a high haplotipic diversity (h) = 0,859 and nucleotic diversity (π) = 0,05026. Mantel Test shown a strong positive correlation among geographic distribution and genetic diversity. Analysis also shown a scenario where the Isbrueckerichthys ancestral reaches the higher lands from the coastal Drainages through a river capture process about 12 million years ago. The results confirm the hypothesis that driver capture events in Ponta Grossa Arch region contributes for the diversity and shape their distribution in Tibagi river basin, and proposes the incipient speciation among I. saxicola e I. calvus in this region.
Key-words: biogeography, headwaters capture, species delimitation, GMYC
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Ontogeny, Homology and Heterochrony in the Siluriform Skeleton

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Kubicek, Kole Matthew (2020). Investigation of Ontogeny, Homology and Heterochrony in the Siluriform Skeleton. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /193002.

https://oaktrust.library.tamu.edu/handle/1969.1/193002
Catfishes (Otophysi: Siluriformes) is a remarkably diverse assemblage (~4000 spp) that is distributed across the globe in fresh and marine waters. Catfishes are united by several modifications of the skeleton, including the extreme modification of certain elements (e.g., the pectoral-fin spine) and the presence of several bones that are currently presumed to be the result of fusion (e.g., the parieto-supraoccipital). In light of this, there have been a vast number of anatomical investigations of the adult skeleton in catfishes; however, comprehensive information on early development of the skeleton remains scarce. This dissertation reports detailed information on the development of the skeleton in catfishes to address issues of homology, provide ontogenetic information on a systematically important character complex, and assess the role that heterochrony may have played in the evolution of the skeleton. I provide a detailed description of skeletal development for two species of North American catfish, Ictalurus punctatus and Noturus gyrinus. Development of the skeleton was complete by 22.4 mm SL in I. punctatus and 14.1 mm SL in N. gyrinus, excluding the dorsal- and anal-fin distal radials in the latter. No major differences were identified between the ossification sequences compiled for each species. No signs of ontogenetic fusion were observed in previously purported compound elements. I also examined the development of the pectoral-fin spine across the order to determine if it develops from a single ontogenetic pathway and standardize terminology of the spine ornamentation for use in systematic studies. The earliest stages of pectoral-fin spine development were highly conserved across the order and most of the morphological diversity of the structure can be attributed to the presence/absence of five traits (distal rami, anterior/posterior serrae, denticuli, and odontodes). Finally, I compare the ossification sequences of four catfishes and 3 non-siluriform otophysans in order to determine what heterochronic shifts (changes in the relative timing of developmental events), if any, are characteristic of catfishes. Eight different bones were found to be shifted in their appearance within the ossification sequence of catfishes, including the morphologically diverse and functionally important pectoral-fin spine.
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Parotocinclus jumbo is a species complex of at least 5 species

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Dantas, O. B. (2022). Geographic distribution of Parotocinclus jumbo complex species (Loricariidae, Hypoptopomatinae) in drainages in northeastern Brazil. Bachelor's thesis, Universidade Federal do Rio Grande do Norte, Natal.

Dantas, O.B. (2022). Distribuição geográfica das espécies do complexo de Parotocinclus jumbo (Loricariidae, Hypoptopomatinae) nas drenagens do nordeste do Brasil. Trabalho de conclusão de curso (Graduação em Ciências Biológicas) – Universidade Federal do Rio Grande do Norte, Natal.

https://repositorio.ufrn.br/handle/123456789/46847
PDF: https://repositorio.ufrn.br/bitstream/1 ... s_2022.pdf
Abstract
The genus Parotocinclus has many beetle species described from the watersheds of Northeastern Brazil, mainly in the Caatinga. Most of these fish have a restricted geographic distribution, usually occurring in a single basin, including endangered species. However, has a wide geographic distribution, known in several basins in the Northeast region. In an integrative taxonomy study of this beetle from six of the eight basins in which it occurs, it was indicated that P. jumbo is a species complex with at least four new species [emphasis added], which are in the description phase. Thus, in this work we address some taxonomic uncertainties involving morphological and molecular data of two P. jumbo lineages, which occur in the Coruripe and Capibaribe river basins. The results here suggest that these two lineages belong to the species already identified and in the description phase, with the lineage that occurs in the Capibaribe River belonging to P. jumbo, which also occurs in the Rio Paraíba do Norte, and the lineage present in the Rio Coruripe belonging to Parotocinclus sp. n. 3, present in the basins of the Paraíba do Meio and Ipojuca rivers. Therefore, we suggest the expansion of the geographic distribution of these species so that P. jumbo registers occurrence in the basins of the rivers Paraíba do Norte and Capibaribe; and Parotocinclus sp. n. 3 records occurrence in the basins of the Ipojuca, Paraíba do Meio and Coruripe rivers, being the only species of the group with presence in basins inserted in the Atlantic Forest and Caatinga biomes, which includes relevant information to assess their conservation status.
Keywords: Integrative taxonomy; Caatinga fishes; Morphology; Genetics; Coastal basins
Resumo
O gênero Parotocinclus possui muitas espécies de cascudinhos descritas das bacias hidrográficas do Nordeste do Brasil, principalmente na Caatinga. A maioria desses peixes apresenta distribuição geográfica restrita, geralmente ocorrendo em uma única bacia, incluindo espécies ameaçadas de extinção. No entanto, , possui uma ampla distribuição geográfica, conhecida em diversas bacias da região do Nordeste. Em um estudo de taxonomia integrativa desse cascudinho de seis das oito bacias em que ocorre, indicou que P. jumbo se trata de um complexo de espécies com pelo menos quatro espécies novas, que estão em fase de descrição. Com isso, neste trabalho tratamos algumas incertezas taxonômicas envolvendo dados morfológicos e moleculares de duas linhagens de P. jumbo, as quais ocorrem nas bacias dos rios Coruripe e Capibaribe. Os resultados aqui sugerem que essas duas linhagens pertencem às espécies já identificadas e em fase de descrição, sendo a linhagem que ocorre no Rio Capibaribe pertencente a P. jumbo, que também ocorre no Rio Paraíba do Norte, e a linhagem presente no Rio Coruripe pertencente a Parotocinclus sp. n. 3, presente nas bacias dos rios Paraíba do Meio e Ipojuca. Portanto, sugerimos a expansão da distribuição geográfica dessas espécies de modo que P. jumbo registra ocorrência nas bacias dos rios Paraíba do Norte e Capibaribe; e Parotocinclus sp. n. 3 registra ocorrência nas bacias dos rios Ipojuca, Paraíba do Meio e Coruripe, sendo as únicas espécies do grupo com presença em bacias inseridas nos biomas de Mata Atlântica e Caatinga, o que contempla com informações relevantes para avaliar o seu estado de conservação.
Palavras chaves: Taxonomia integrativa; Peixes da Caatinga; Morfologia; Genética; Bacias costeiras
Attachments
Figura 1 – Mapa de distribuição das linhagens de P. jumbo nas drenagens do Nordeste do Brasil.
Figura 1 – Mapa de distribuição das linhagens de P. jumbo nas drenagens do Nordeste do Brasil.
Figura 3 – Árvore parcial de Máxima verossimilhança demonstrando as relações de Parotocinclus jumbo na subfamília Hypoptopomatinae. Número acima dos ramos são valores de bootstrap para 1.000 pseudoréplicas. Destacado da cor amarelo os espécimes de P. jumbo da bacia do rio Capibaribe. Destacado da cor rosa os espécimes de P. jumbo da bacia do rio Coruripe. Siglas: PjumbJAG – P. jumbo do rio Jaguaribe, PjumbPIA – P. jumbo do rio Piranhas-Açú, PjumbPBN – P. jumbo do rio Paraíba do Norte, PjumbPBM – P. jumbo do rio Paraíba do Meio, PjumbIPO – P. jumbo do rio Ipojuca, PjumbSFR – P. jumbo do rio São Francisco, e PjumbCAP – P. jumbo do rio Capibaribe.
Figura 3 – Árvore parcial de Máxima verossimilhança demonstrando as relações de Parotocinclus jumbo na subfamília Hypoptopomatinae. Número acima dos ramos são valores de bootstrap para 1.000 pseudoréplicas. Destacado da cor amarelo os espécimes de P. jumbo da bacia do rio Capibaribe. Destacado da cor rosa os espécimes de P. jumbo da bacia do rio Coruripe. Siglas: PjumbJAG – P. jumbo do rio Jaguaribe, PjumbPIA – P. jumbo do rio Piranhas-Açú, PjumbPBN – P. jumbo do rio Paraíba do Norte, PjumbPBM – P. jumbo do rio Paraíba do Meio, PjumbIPO – P. jumbo do rio Ipojuca, PjumbSFR – P. jumbo do rio São Francisco, e PjumbCAP – P. jumbo do rio Capibaribe.
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Descriptions and Phylogenetic Relationships of the Guiana Shield Pencil Catfishes

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Akin, D. (2022). Descriptions and Phylogenetic Relationships of the Guiana Shield Pencil Catfishes. Master's Thesis, Auburn University.

https://etd.auburn.edu/handle/10415/8300
The systematics of the catfish genus Valenciennes 1832 are complicated and unresolved. This genus is paraphyletic, containing all members of the Trichomycterinae that cannot be adequately placed into an established genus due to the paucity of clearly defining characters that separated the lineages within this subfamily. The complete revision of is a daunting task, and one that cannot be undertaken until most of the diversity within geographically relevant clades are described. This study describes six new species of of the Pakaraima Mountains and nearby Kusad Mountain of the Guiana Shield region of South America. Additionally, I explore the phylogenetic relationships of these species and construct a time-calibrated phylogeny of the lineage within the Trichomycterinae. The results presented here suggest that there are two clades of in the Guiana Shield, one species described in this study may constitute a species complex, that the diversification within the lineage occurred concurrently with the rise of the Andes Mountains, and that upper portion of the Ireng River may have flown north into the Grand Pakaraima River before being captured by the modern-day Rio Branco.
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Evolutionary Ecology of Loricariid Catfishes

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MODERATOR'S NOTE: This paper was published on 2 November 2022: viewtopic.php?t=51252

Black, C. (2022). Evolutionary Ecology of Loricariid Catfishes. Ph.D. dissertation, Auburn University.

https://etd.auburn.edu/handle/10415/8312

PDF: https://etd.auburn.edu/bitstream/handle ... sAllowed=y
Abstract
How extrinsic (like functional constrains and ecological interactions) and intrinsic (like modularity and integration) interactions drive diversification is a formative area of evolutionary biology. In this dissertation, I explore the phenotypic diversification of the armored catfishes using geometric morphometrics, stable isotope analyses, and phylogenetic comparative methods. I found that the armored catfish body is highly modularized, with varying degrees of integration between each module, suggesting that interactions within and between modules influence morphological evolution. Additionally, slight changes in modularity and integration patterns in clades may have allowed for diversification along a specific trajectory. When focused on the oral jaw shape, I found that traditional and automated processes captured shape more effectively when all jaw components were combined. Although ecological traits do not play a role in jaw shape, there was a correlation between clades with diverse diets and fast evolutionary rates of shape. These results suggest that shape is not constrained to diet and that similarly shaped jaws coupled with different types of teeth could allow the fishes to feed on a wide range of materials. Finally, I built a vector-based analysis, baseline‐standardized isotopic vector analysis (BaSIVA) to visualize dietary variation while accounting for isotopic discrepancies between locations. Results from BaSIVA delineate trophic groups better than traditional trophic positioning methods while accounting for variation in basal resources, suggesting BaSIVA should be the standard for vector‐based stable isotope analysis in riverine environments with similar baseline resources.
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Re: Diversity of Trichomycterus in the Rio Doce basin

Post by Jools »

bekateen wrote: 17 Oct 2018, 05:37 Ten new species proposed:
  • sp. nov.
  • T. barrocus sp. nov.
  • T. brucutu sp. nov.
  • T. illuvies sp. nov.
  • T. melanopygius sp. nov.
  • T. ipatinguensis sp. nov.
  • T. pussilipygius sp. nov.
  • T. sordislutum sp. nov.
  • T. vinnulus sp. nov.
  • T. tantalus sp. nov.
This one now published. What do I do - create a new post?

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Re: Diversity of Trichomycterus in the Rio Doce basin

Post by bekateen »

Jools wrote: 20 Nov 2022, 12:15 [
This one now published. What do I do - create a new post?

Jools
That's what I've been doing, then I link the two posts together with a moderators note. Perfect example is my thesis post immediately above yours here. Take a look:
bekateen wrote: 01 Aug 2022, 14:44 MODERATOR'S NOTE: This paper was published on 2 November 2022: viewtopic.php?t=51252

Black, C. (2022). Evolutionary Ecology of Loricariid Catfishes. Ph.D. dissertation, Auburn University.

https://etd.auburn.edu/handle/10415/8312
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Re: The Dissertations Sticky

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OK, I will do, I didn't see that as I was at the original post a bit back up the thread. All should be done now,

Cheers,

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Two new species of Pariolius; New genus on the horizon

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new species
new species
Coming soon (maybe): new genus
may get a new generic designation, but is not yet renamed.

Fuster, D. R. F. (2022). Análise filogenética de Heptapteridae gill, 1861 e taxonomia integrativa de Heptapterus bleeker, 1858 (Heptapterinae: heptapterini). Ph.D. Dissertation. Graduate Program in Animal Biology, Instituto de Biociências da Universidade Federal do Rio Grande do Sul. Porto Alegre, Brazil.
https://www.lume.ufrgs.br/handle/10183/245860
PDF: https://www.lume.ufrgs.br/bitstream/han ... sequence=1
ABSTRACT
The Heptapteridae family contains 23 genera and 231 valid species that are specific in a wide range of freshwater habitats from southern Mexico to northern Argentina. A current phylogenetic systematics of Heptapteridae is significantly shaped by an unpublished morphology-based analysis of most extant genera carried out over 20 years ago. We provide a new multilocus molecular phylogenetic hypothesis encompassing 19 of 23 valid genera in Heptapteridae, including all valid genera of Brachyglaniini (4 of 4), 11 of 14 valid genera of Heptapterini and 66% of all valid species of Heptapterini (58 of 88, plus many new species). The analysis includes 15 type species from the 23 valid genera of Heptapteridae. The present work is based on a multilocus analysis of five molecular markers, being three mitochondrial markers (COI, cytochrome oxidase subunit I; Cyt b: cytochrome be ND2: NADH dehydrogenase subunit 2) and two nuclear markers (RAG2: recombination activating 2, and Glyt: glycosyltransferase), and have recovered generally well-resolved and consistently supported phylogenies. Based on these results, we provide a new suprageneric classification within Heptapteridae, subdivided into: Heptapterinae (comprising Brachyglaniini and Heptapterini) and Rhamdiinae (containing Rhamdiini and Goeldiellini); five new subtribes were recovered within Heptapterini. This work includes an integrative analysis of the genus , type genus of the family, that is redefined and limited to four valid species. It includes the description of a new genus sister of Heptapterus and containing two new species. Finally, we present the description of new species within Heptapteridae.
RESUMO
A família Heptapteridae contém 23 gêneros e 231 espécies válidas que são encontradas em uma ampla gama de habitats de água doce do sul do México ao norte da Argentina. A sistemática filogenética atual de Heptapteridae é significativamente moldada por uma análise baseada em morfologia da maioria dos gêneros existentes, realizada há mais de 20 anos e não publicada. Nós fornecemos uma nova hipótese filogenética molecular abrangendo 19 dos 23 gêneros válidos em Heptapteridae, incluindo todos os gêneros válidos de Brachyglaniini (4 de 4), 11 dos 14 gêneros válidos de Heptapterini e 66% de todas as espécies válidas de Heptapterini (58 de 88; além de muitas espécies não descritas). A amostragem inclui 15 espécies tipo dos 23 gêneros válidos de Heptapteridae. O presente trabalho, baseado em uma análise multilocus de cinco marcadores moleculares, 3 marcadores mitocondriais (COI, cytochrome oxidase subunit I; Cyt b: cytochrome b e ND2: NADH dehydrogenase subunit 2), e dois marcadores nuclear (RAG2: recombination activating 2, e Glyt: glycosyltransferase), produziu filogenias geralmente consistentes, bem resolvidas e fortemente suportadas. Com base nesses resultados, fornecemos uma nova classificação supragenérica dentro de Heptapteridae subdividida em: Heptapterinae (contendo Brachyglaniini e Heptapterini) e Rhamdiinae (contendo Rhamdiini e Goeldiellini); dentro de Heptapterini foram reconhecidas cinco subtribos novas. O trabalho inclui uma análise integrativa do gênero espécie tipo da família onde o gênero foi redefinido e limitado a 4 quatro espécies validas, com a descrição de um gênero novo irmão de Heptapterus contendo duas espécies novas. Finalmente apresentamos descrições de novas espécies de Heptapteridae.
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Systematics of the genus Rhyacoglanis

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Rodrigues, Jefferson Luan Crispim. (2023). Systematics of the genus Rhyacoglanis Shibatta & Vari, 2017 (Siluriformes: Pseudopimelodidae). Paulista State University (Unesp). Available at: < http://hdl.handle.net/11449/239252 >.

https://repositorio.unesp.br/handle/11449/239252
Abstract
Within the great diversity of Neotropical fish, we can highlight the Pseudopimelodidae family, a group of catfish widely distributed throughout South America, whose representatives have been characterized by the presence of a yellow body color with dark bars, which associates them with the popular name of bumblebee. catfishes, covering two subfamilies, namely, Batrochoglaninae and Pseudopimelodinae, which includes the genus . In order to improve understanding and understanding, this Course Completion Work is divided into two chapters: In the first, the molecular delimitation of the species of the genus Rhyacoglanis was carried out using the cytochrome c oxid markerase subunit I (COI) to carry out a delimitation analysis of species of the genus. Fourteen samples of muscle tissue from species of the genus Rhyacoglanis, from the hydrographic basins of the Paraná, Paraguay, Xingu, Tapajós and Madeira rivers, covering a wide geographic distribution for the genus, were used. For the species delimitation analysis, we used the ASAP program, which, in its first partition, indicated the existence of four independent lineages and in its second partition it indicated five lineages, namely, R. annulatus, R. pulcher, R. variolosus and two new species, one for the Tapajós river basin and another for the Xingu river basin. In the second chapter, a new species of Rhyacoglanis is described for the rio Jamanxim, rio Tapajós basin.
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Re: The Dissertations Sticky

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Obafunmiso, H. (2023). Behavioral response to conspecific sounds in Loricariid catfishes (Pterygoplichtys pardalis and Otocinclus vittatus). Master's thesis, 3661, Biology Department, Western Kentucky University. Online Aug 2023.

https://digitalcommons.wku.edu/theses/3661/
Abstract
Sound production is a means of communication among many fish species. In fishes, sound is produced through various mechanisms, but in the family Loricariidae, known as armored suckermouth catfishes, sound is produced primarily through pectoral fin spine stridulation. Previous experiments have described the sounds produced and shown the mechanism of sound production in two species of loricariid catfishes, and , but the functional significance of loricariid sounds is still unknown. To address this question, I examined the behavioral responses of Pterygoplichthys pardalis and Otocinclus vittatus to conspecific calls. Individual fish (N=10 for P. pardalis) or groups of 20 fish (N=4 groups for O. vittatus) were acclimated to an aquarium for at least 24 h. Individual P. pardalis were video recorded for 2 minutes with no sound, plus another 2 minutes with a playback of either a 500 Hz tone control or conspecific call through an underwater speaker. In contrast, O. vittatus was video recorded for 5 minutes with no sound, with an additional 5 minutes of either conspecific call or 500 Hz tone stimuli. This procedure was repeated for each individual or group using either a 500 Hz tone and conspecific call for playback so that each individual or group received both stimuli. I hypothesized that P. pardalis would avoid, while O. vittatus would be attracted to, the conspecific sound-emitting speaker, respectively. The rationale for this hypothesis is that P. pardalis produces calls when it is under duress, so it may be an alarm call, while O. vittatus produces calls spontaneously in large groups of fish, suggesting it may be a cohesion call or involved in other intraspecific interactions. P. pardalis showed an increased activity level to conspecific sound compared to the 500 Hz tone, although movement in general was minimal, while O. vittatus exhibited a short-lived response to conspecific calls by moving toward the speaker with the sound source. Since both species showed a minimal behavioral change to sound playbacks, more research is needed to better understand the function of sound production in loricariid catfishes.
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Reproductive biology of Loricariichthys anus

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Selle, D.C. (2023). Characterization of the reproductive biology of fiddle (Loricariichthys anus). Master's Dissertation in Zootechnics – Animal Production, Faculty of Agronomy, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. (69 p.) March, 2023. Creative Commons license by-nc-sa 2.5

Selle, D.C. (2023). Caracterização da biologia reprodutiva de violinha (Loricariichthys anus). Dissertação de Mestrado em Zootecnia – Produção Animal, Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil. (69 p.) março, 2023. Creative Commons license by-nc-sa 2.5

https://lume.ufrgs.br/handle/10183/263176
PDF: https://lume.ufrgs.br/bitstream/handle/ ... sAllowed=y
ABSTRACT - The "violinha" () has been commercially prominent in southern Brazil in the last three decades, becoming a vital fishery resource. Given its high market acceptance in Rio Grande do Sul, it is the second most consumed native fish in the Holy Week in 2021, being seen as a species with great potential for aquaculture. To perform the sexual characterization of the species and elucidate critical biological aspects for the development of captive breeding protocols, the present study was carried out the following analyses aiming to characterize the annual reproductive cycle: sexual dimorphism, gonadosomatic index (GSI), gonadal histology of males and females, sperm kinetics, sperm concentration, and sperm morphology. To analyze the variations of these factors throughout the year, six males and six females were collected monthly in the Guaíba River from November 2021 to October 2022, totaling 144 animals (51.02 ± 16.61 g and 22.3 ± 1.96 cm). The animals were anesthetized, euthanized, measured, and weighed, and their gonads were obtained by dissection and weighed on a precision scale. Part of each male gonad was macerated to get semen (for kinetic, concentration, and morphological analysis), and the other part, along with the female gonads, was fixed in Glutaraldehyde 2,5% for further histological analysis. The morphological evaluation of the animals was based on evaluation studies of the Loricariidae family. Was obtained a single characteristic for dimorphism the lower lip of males (7.8 ± 2.71 mm), which presented elongation of 2 to 3 times its standard size (5.3 ± 0.70 mm), besides showing darkening on the sides and final portion of the lower lip, during the months of November to March. As for the IGS analysis, the data were observed, month by month for males and females, presenting the following variation, respectively: 0.41 ± 0.10 and 4.73 ± 0.51 (November); 0.35 ± 0.11 and 5.53 ± 1.33 (December); 0.41 ± 0.11 and 4.29 ± 1.91 (January); 0.55 ± 0.09 and 3.29 ± 3.57 (February); 0.16 ± 0.09 and 0.68 ± 0.94 (March); 0.17 ± 0.07 and 0.90 ± 0.40 (April); 0.06 ± 0.03 and 0.69 ± 0.59 (May); 0.24 ± 0.05 and 0.94 ± 0.42 (June); 0.18 ± 0.12 and 0.72 ± 0.28 (July); 0.28 ± 0.21 and 0.73 ± 0.59 (August); 0.14 ± 0.03 and 1.53 ± 1.40 (September); 0.21 ± 0.13 and 2.79 ± 3.93 (October). The fixed gonads were embedded in paraplast and sectioned on a manual microtome to assemble slides, stained with hematoxylin and eosin, and analyzed by light microscopy to identify the phases of gonadal maturation over the months. For females, the analyzes indicate that between November and March, they presented mature oocytes, in addition to demonstrating that there is more than one occurrence of total spawning during the reproductive period. On the other hand, males did not present a defined reproductive period, with the occurrence of spermatozoa throughout the year, but with low volumes, and from December on, the testicles are already observed regressing, with a large volume of spermatogonial cells. For the sperm kinetics analysis (Motility - MOT; curvilinear velocity - VCL; straight line velocity - VSL; mean displacement velocity - VAP and progressivity - PROG), performed with the CASA software, the semen samples were diluted in Hank's Solution and later activated with distilled water. There were differences (p>0.05) for MOT between the analyzed periods of November, January, and March (25.58 ± 0.05; 1.97 ± 0.02 and 2.11 ± 0.005 %); VCL (58.8 ± 4.47; 37.59 ± 5.29 and 41.28 ± 6.9 μm/s, respectively) and VAP (40.1 ± 4.99; 20.71 ± 3.04 and 22.87 ± 5.61 μm/s). For sperm concentration, the samples were placed in a Neubauer chamber where a 5-field subjective count was performed. Subsequently, the value found was converted, presenting an average of 9,741,600 ± 1,208,834 spermatozoa/ml of semen, but only during the reproductive period (November to March). In the other months, we did not obtain enough semen volume to perform the analysis. For morphology, 200 spermatozoa were counted in each analysis, getting the following values: normal sperm 103 ± 21.79; loose head 69 ± 14.77; short tail 7 ± 3.68; degenerated head 6 ± 4.16; macrocephaly 4 ± 3.16; microcephaly 2 ± 2.09. With the data obtained from IGS and gonadal histology, it can be stated that the reproductive period of L. anus occurs between November and February in the Guaíba River, corroborating the information that the species presents sexual dimorphism only during the reproductive period. It is also possible to state that the species shows a low amount of viable spermatozoa during the reproductive period, besides a low sperm concentration, when compared to other species of the order Siluriforme or even the family Loricariidae, and this may be a bottleneck for the reproduction of the species in captivity.
Keywords: Sperm kinetics; sperm concentration; sexual dimorphism; IGS; sperm morphology.
RESUMO - A violinha (Loricariichthys anus) vem se destacando comercialmente no sul do Brasil nas últimas três décadas, tornando-se um importante recurso pesqueiro. Visto sua elevada aceitação de mercado no Rio Grande do Sul, é o segundo peixe nativo mais consumido na semana santa em 2021, sendo vista como uma espécie com grande potencial para aquicultura. Com intuito de realizar a caracterização sexual da espécie e elucidar aspectos biológicos importantes para o desenvolvimento de protocolos de reprodução em cativeiro, o presente estudo realizou as seguintes análises com o objetivo de caracterizar o ciclo reprodutivo anual: Dimorfismo sexual; Índice Gonadossomático (IGS); Histologia gonadal de machos e fêmeas; Cinética espermática; Concentração espermática; e Morfologia espermática. Para analisar as variações desses fatores ao longo do ano, foram coletados no rio Guaíba, de novembro de 2021 a outubro de 2022, seis machos e seis fêmeas ao mês, totalizando 144 animais (51,02 ± 16,61 g e 22,3 ± 1,96 cm). Os animais foram anestesiados, eutanasiados, mensurados e pesados e suas gônadas foram obtidas por dissecação, pesadas em balança de precisão. Parte de cada uma das gônadas masculinas foram maceradas afim de se obter sêmen (para as analises cinéticas, de concentração e morfológica), e a outra parte, juntamente com as gônadas femininas, fixadas em glutaraldeído 2,5% para posterior análise histológica. A avaliação morfológica dos animais baseou-se em trabalhos de avalição para Família Loricariidae, obtendo-se um único ponto de dimorfismo, o lábio inferior dos machos (7,8 ± 2,71 mm), que apresentou alongamento de 2 a 3 vezes o seu tamanho normal (5,3 ± 0,70 mm), além de apresentar escurecimento nas laterais e porção final do lábio inferior, durante os meses de novembro a março. Quanto à análise do IGS, os dados foram observados, mês a mês para machos e fêmeas foram, apresentação a seguinte variação, respectivamente: 0,41 ± 0,10 e 4,73 ± 0,51 (novembro); 0,35 ± 0,11 e 5,53 ± 1,33 (dezembro); 0,41 ± 0,11 e 4,29 ± 1,91 (janeiro); 0,55 ± 0,09 e 3,29 ± 3,57 (fevereiro); 0,16 ± 0,09 e 0,68 ± 0,94 (março); 0,17 ± 0,07 e 0,90 ± 0,40 (abril); 0,06 ± 0,03 e 0,69 ± 0,59 (maio); 0,24 ± 0,05 e 0,94 ± 0,42 (junho); 0,18 ± 0,12 e 0,72 ± 0,28 (julho); 0,28 ± 0,21 e 0,73 ± 0,59 (agosto); 0,14 ± 0,03 e 1,53 ± 1,40 (setembro); 0,21 ± 0,13 e 2,79 ± 3,93 (outubro). As gônadas fixadas foram incluídas em paraplast e seccionadas em micrótomo manual para a montagens das lâminas, as quais foram coradas em hematoxilina e eosina e analisadas por microscopia óptica para identificação das fases de maturação gonadal ao longo dos meses. Para fêmeas as análises indicam que entre novembro e março apresentaram oócitos maduros, além de demonstrar que há mais de uma ocorrência de desova total durante o período reprodutivo. Já os machos não apresentaram período reprodutivo definido, com ocorrência de espermatozoides durante todo o ano, porém em baixos volumes e, a partir de dezembro, já se observa os testículos regredindo, com um grande volume de espermatogônias. Para a análise da cinética espermática (Motilidade - MOT; velocidade curvilínear - VCL; velocidade em linha reta - VSL; velocidade média de deslocamento - VAP e progressividade - PROG), realizada com o software CASA, as amostras de sêmen foram diluídas em Solução de Hank's e posteriormente ativadas com água destilada. Houve diferença (p>0,05) para MOT entre os períodos analisados de novembro, janeiro e março (25,58 ± 0,05; 1,97 ± 0,02 e 2,11 ± 0,005 %); VCL (58,8 ± 4,47; 37,59 ± 5,29 e 41,28 ± 6,9 μm/s, respectivamente) e VAP (40,1 ± 4,99; 20,71 ± 3,04 e 22,87 ± 5,61 μm/s). Para concentração espermática, as amostras foram posicionadas em câmara de Neubauer onde realizou-se a contagem de subjetiva de 5 campos e, posteriormente, o valor encontrado foi convertido, apresentando a média de 9.741.600 ± 1.208.834 espermatozoides/ml de sêmen, mas apenas durante o período reprodutivo (novembro a março). Nos demais meses não se obteve volume suficiente de sêmen para realizar a análise. Para morfologia foram contabilizados 200 espermatozoides em cada análise, obtendo-se os seguintes valores: Espermatozoides normais 103 ± 21,79; Cabeça solta 69 ± 14,77; Cauda curta 7 ± 3,68; Cabeça degenerada 6 ± 4,16; Macrocefalia 4 ± 3,16; Microcefalia 2 ± 2,09. Com os dados obtidos de IGS e histologia gonadal, pode-se afirmar que o período reprodutivo de L. anus ocorre entre os meses de novembro e fevereiro no rio Guaíba, corroborando com a informação de que a espécie apresenta dimorfismo sexual apenas durante o período reprodutivo. Também é possível afirmar que a espécie apresenta uma baixa quantidade de espermatozoides viáveis durante o período reprodutivo, além de baixa concentração espermática, quando comparadas à outras espécies da ordem Siluriforme ou, até mesmo, da família Loricariidae, podendo este ponto ser um gargalo para reprodução da espécie em cativeiro.
Palavras-chave: Cinética espermática; concentração espermática; dimorfismo sexual; IGS; morfologia espermática.
Attachments
Figure 1. Illustrative image of a specimen of the yellow-bellied catfish Loricariichthys anus. Photo: Douglas Cosme Selle (Collection carried out in October 2022).
Figure 1. Illustrative image of a specimen of the yellow-bellied catfish Loricariichthys anus. Photo: Douglas Cosme Selle (Collection carried out in October 2022).
Figure 9. Images exemplifying the three groups used to distinguish the color of the upper and lower lips of the viola (Loricariichthys anus): A) specimen with Normal lip; B) specimen with dark edges of the lower and upper lips; and C) specimen with dark Perimeter of the lower and upper lips.
Figure 9. Images exemplifying the three groups used to distinguish the color of the upper and lower lips of the viola (Loricariichthys anus): A) specimen with Normal lip; B) specimen with dark edges of the lower and upper lips; and C) specimen with dark Perimeter of the lower and upper lips.
Figure 3. Image of a male specimen of yellow-bellied catfish (Loricariichthys anus) incubating fertilized eggs on its lower lip. Photo: Daniela Pereira da Rosa.
Figure 3. Image of a male specimen of yellow-bellied catfish (Loricariichthys anus) incubating fertilized eggs on its lower lip. Photo: Daniela Pereira da Rosa.
Figure 6. Image demonstrating the embryonic development of Loricaria coximensis. Photo: IMASUL, 2019.
Figure 6. Image demonstrating the embryonic development of Loricaria coximensis. Photo: IMASUL, 2019.
Figure 4. Larval development of the yellow-bellied catfish (Loricariichthys anus). Photo: Daniela Pereira da Rosa.
Figure 4. Larval development of the yellow-bellied catfish (Loricariichthys anus). Photo: Daniela Pereira da Rosa.
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Ontogeny and phylogeny in Trichomycteridae

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Reis, V. J. C. (2023). Ontogeny and phylogeny in Trichomycteridae (Teleostei, Siluriformes): patterns in the development of morphological complexes. Doctoral Thesis, Museu de Zoologia, University of São Paulo, São Paulo. doi:10.11606/T.38.2023.tde-17082023-144452. Retrieved 2023-09-23, from www.teses.usp.br
https://doi.org/10.11606/T.38.2023.tde-17082023-144452
https://www.teses.usp.br/teses/disponiv ... 452/en.php
Abstract
This thesis offers the first large-scale study on the ontogeny of the musculoskeletal system in Trichomycteridae and its implications for understanding the phylogenetic relationships and evolution of the family. Trichomycteridae is a monophyletic group of neotropical catfish with exceptionally rich morphological diversity. This diversity is reflected in a wide range of habitats and trophic niches. The feeding habits of the group vary from invertivores to strict hematophagy, the latter a unique case in Actinopterygii. Using developmental series and juvenile specimens representing most trichomycterid lineages, detailed descriptions of the development of various musculoskeletal systems of the head, such as the mandibular complex, opercular apparatus, branchial skeleton, suspensorium, and neurocranium are presented. Such information, new for the most part, provides a solid framework for formulating and testing hypotheses of homology, some of which representing long-standing controversies in Siluriformes, such as the supraoccipital, parietal, pterotic, extrascapular, and posttemporal. Observations also permit direct mapping of transformation sequences and connections between highly divergent conditions in adult specimens, such as the mouth apparatus of juveniles and adults of Vandelliinae. Results obtained are incorporated into new morphological and total evidence phylogenetic analyses with broader taxonomic and data density than previously available, allowing a detailed understanding of the diversification history of Trichomycteridae. Those results are combined with developmental information to provide an ontogenetic framework for testing a new method for detecting heterochronies designed to map paedo- and peromorphic phenomena in the family. The most relevant phylogenetic results are that Microcambevinae probably result from long-branched attraction, and the identification of a new clade composed of Stenolicmus ix and Ammoglanis pulex, previously assigned to Sarcoglanidinae, and the removal of Potamoglanis from Tridentinae. The synergism of phylogenetic hypothesis with ontogeny reveals wide-evolutionary patterns, showing that Trichomycteridae is a mostly paedomorphic family, a ground plan upon which numerous internested peramorphic apomorphies have evolved. One major event of miniaturization occurred at the base of a large clade, here named the miniature clade. Within that clade, there are various events of further reduction in size. Surprisingly, within the miniature clade there is also an event of reverse size-increase, a phenomenon detected not only by phylogenetic structure but also by marks left in the structure and development of different anatomical complexes.
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Evolutionary biogeography of catfishes

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Janzen, F. (2023). Evolutionary biogeography of catfishes (Siluriformes, Actinopterygii): The influence of habitat and landscape on gene flow and genetic diversification. PhD Dissertation, Ottawa-Carleton Institute of Biology, University of Ottawa, Canada.
https://ruor.uottawa.ca/handle/10393/45512
Abstract
A fundamental goal of evolutionary biology is to understand what processes have led to the great diversity of organisms we see today. An important factor of diversification is an organism’s environment. Abiotic factors can shape the evolutionary trajectory of species by affecting fundamental mechanisms of evolution, including mutation, gene flow, genetic drift, and natural selection. In my thesis, I investigated how abiotic factors, such as habitat and landscape, have influenced the genetic diversification of catfishes (Siluriformes). More specifically, I compared genetic data within and between species to understand how natural barriers have shaped the origins and evolutionary trajectory of species. In Chapter 1, I investigated whether habitat preferences and segregation of breeding populations in lacustrine-like and fluvial habitats affected the genetic structure of a sympatric population of channel catfish (). In Chapter 2, I elucidated the origins of cave species within North American catfishes (Ictaluridae), determining whether they shared a common ancestor or evolved in parallel from surface-dwelling ancestors. In Chapter 3, I tested whether impermeable and semi-permeable boundaries between South American river basins have restricted gene flow and resulted in potentially new species within the widespread ornate pim catfish (). In Chapter 4, I determined whether orogenesis and river capture corresponded with speciation events and cladogenesis within Neotropical long-whiskered catfishes (Pimelodidae). Throughout my thesis, I observed evolutionary patterns related to gene flow, vicariance, and dispersal. Physical barriers imposed on populations often coincided with genetic diversification and allopatric speciation. These barriers reduced gene flow, allowing populations to genetically diverge in response to unique selective pressures. As these barriers changed over time, dispersal opportunities may have further promoted diversification as species radiated into new areas. I also observed that ecological gradients, such as water chemistry, may have facilitated parapatric speciation; however, differences between habitats do not always restrict gene flow. Given that patterns of genetic diversification and speciation are not uniform across the tree of life, it is important for evolutionary biologists to document trends among different taxa to elucidate macroevolutionary patterns.
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