New Horaglanis

For the discussion of catfish systematics. Post here to draw our attention to new publications or to discuss existing works.
Post Reply
User avatar
Posts: 12298
Joined: 31 Dec 2002, 11:35
My articles: 55
My images: 872
My catfish: 1
My cats species list: 90 (i:0, k:0)
Spotted: 411
Location 1: Singapore
Location 2: Moderator Emeritus

New Horaglanis

Post by Silurus »

Raghavan R, RL Sundar, CP Arjun, R Britz & N Dahanukar, 2023, Evolution in the dark: unexpected genetic diversity and morphological stasis in the blind, aquifer-dwelling catfish Horaglanis. Vertebrate Zoology 73: 57-74.


The lateritic aquifers of the southern Indian state of Kerala harbour a unique assemblage of enigmatic stygobitic fishes which are encountered very rarely, only when they surface during the digging and cleaning of homestead wells. Here, we focus on one of the most unusual members of this group, the catfish Horaglanis, a genus of rarely-collected, tiny, blind, pigment less, and strictly aquifer-residing species. A six-year exploratory and citizen-science backed survey supported by molecular phylogenetic analysis reveals novel insights into the diversity, distribution and population structure of Horaglanis. The genus is characterized by high levels of intraspecific and interspecific genetic divergence, with phylogenetically distinct species recovered above a 7.0% genetic-distance threshold in the mitochondrial cytochrome oxidase subunit 1 gene. Contrasting with this deep genetic divergence, however, is a remarkable stasis in external morphology. We identify and describe a new cryptic species, Horaglanis populi, a lineage that is the sister group of all currently known species. All four species are represented by multiple haplotypes. Mismatch distribution reveals that populations have not experienced recent expansions.
Post Reply