Benthic suction feeding in Callichthyidae and Mochokidae

[Silurus]

Van Wassenbergh, S, T Lieben, A Herrel, F Huysentruyt, T Geerinckx, D Adriaens & P Aerts, 2009. Kinematics of benthic suction feeding in Callichthyidae and Mochokidae, with functional implications for the evolution of food scraping in catfishes. Journal of Experimental Biology 212: 116–125.

Abstract

Food scraping has independently evolved twice from suction feeding in the evolution of catfishes: within neotropical Loricarioidea and paleotropical Mochokidae. To gain insight in the evolutionary transitions associated with the evolution towards scraping, we analyzed prey capture kinematics in two species of benthic suction feeders which belong to taxa that are closely related to the scraper lineages (respectively, Corydoras splendens and Synodontis multipunctatus), and compared it to prey capture in a more distantly related, generalist suction feeder (Clarias gariepinus). Simultaneous ventral and lateral view highspeed videos were recorded to quantify the movements of the lower jaw, hyoid, pectoral girdle and neurocranium. Additionally, ellipse modeling was applied to relate head shape differences to buccal expansion kinematics. Similarly to what has been observed in scrapers, rotations of the neurocranium are minimal in the benthic suction feeders, and may consequently have facilitated the evolution of a scraping feeding mechanism. The hypothesis that fish with a more laterally compressed head rely more heavily on lateral expansion of the buccal cavity to generate suction, was confirmed in our sample of catfish species. Since an important contribution of lateral expansion of the head to suction may avoid the need for a strong, ventral depression of the mouth floor during feeding, we hypothesized that this may have allowed a closer association with the substrate in the ancestors of scrapers. However, our hypothesis was not supported by an ancestral state reconstruction, which suggests that scraping probably evolved from sub-terminal mouthed ancestors with dorsoventrally flattened heads.

[Silurus]

This is the first paper I have seen that uses Corydoras splendens.

[MatsP]

This is the first paper I have seen that uses Corydoras splendens.

That is interesting - one wonders if that is intentional to indicate that they see Brochis and Corydoras as the same species [I presume it is what we call B. splendens that they ARE referring to].

[the article itself appears to be quite interesting too - you don't happen to have a PDF, do you?]

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Mats

[Silurus]

The synonymy of Brochis with Corydoras dates from here, but I have not seen it in the scientific literature until now.

[MatsP]

The synonymy of Brochis with Corydoras dates from here, but I have not seen it in the scientific literature until now.

Ah, ok - I vaguely remember that discussion.

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Mats

[lfinley58]

Hi all.

Ferraris placed the three Brochis species in the genus Corydoras in his 2007 checklist. This should fit well enough as an earlier presentation in the scientific literature.

Lee

[lfinley58]

Hi all. A PDF of the paper is available at: http://webh01.ua.ac.be/funmorph/publica ... p_Biol.pdf

Lee

[Carp37]

I notice the paper refers to Callichthys barbatus for one of the figures- I'm assuming this is a mistake as it certainly looks more like a Scleromystax line drawing than a Callichthys one?

[MatsP]

I notice the paper refers to Callichthys barbatus for one of the figures- I'm assuming this is a mistake as it certainly looks more like a Scleromystax line drawing than a Callichthys one?

I saw that too - which makes one wonder if the "brochis == corydoras" is actually just a mistake, or if it's intentional.

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Mats