Feeding Behaviour of Seven Icefish Species (Channichthyidae) in the Ross Sea, Antarctica

The Channichthyidae, a monophyletic fish group belonging to the suborder Notothenioidei, are uniquely adapted to the polar environment. However, while their physiology has been extensively studied, studies on their ecology are relatively rare. Here, we investigated the trophic ecology of seven icefi...

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Bibliographic Details
Published in:Fishes
Main Authors: Erica Carlig, Davide Di Blasi, Laura Ghigliotti, Andreas Scalas, Andrew L. Stewart, Michela Mortara
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2024
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Online Access:https://doi.org/10.3390/fishes9070247
https://doaj.org/article/3fccdaa5facc475cb00590498474f52a
Description
Summary:The Channichthyidae, a monophyletic fish group belonging to the suborder Notothenioidei, are uniquely adapted to the polar environment. However, while their physiology has been extensively studied, studies on their ecology are relatively rare. Here, we investigated the trophic ecology of seven icefish species ( Chaenodraco wilsoni, Chionobathyscus dewitti, Chionodraco hamatus , Dacodraco hunteri , Neopagetopis ionah , Pagetodes antarcticus and Pagetopsis macropterus ) by using the traditional morphometric approach to assess the relationship between form and feeding function. The suction index (SI), the mechanical advantage in jaw closing (MA) and nine morphological traits related to feeding structures have been analysed. Icefish species are characterised by non-protractible, elongate jaws and a wide gape; such morphological features influence the low values of both MA and SI, supporting their ram-feeding habit. The ecomorphological differences among species resulted mainly determined by the anatomical structures related to SI. Such differences do not seem to be determined primarily by the type of prey, as is the case in other taxonomic groups of Notothenioidei, but rather by phylogenetic proximity. A 3D animation was developed to visualise the different feeding modes of two icefish species ( C. hamatus and P. macropterus ) which are characterised by different approaches to prey.