Royal knifefish generate powerful suction feeding through large neurocranial elevation and high epaxial muscle power

Li, Ellen Y ORCID: 0000-0001-5545-7364, Kaczmarek, Elska B ORCID: 0000-0003-1720-7342, Olsen, Aaron M ORCID: 0000-0003-4398-3126, Brainerd, Elizabeth L ORCID: 0000-0003-0375-8231 and Camp, Ariel L ORCID: 0000-0002-3355-4312
(2022) Royal knifefish generate powerful suction feeding through large neurocranial elevation and high epaxial muscle power. [Preprint]

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<jats:title>ABSTRACT</jats:title><jats:p>Suction feeding in ray-finned fishes involves powerful buccal cavity expansion to accelerate water and food into the mouth. Previous XROMM studies in largemouth bass (<jats:italic>Micropterus salmoides</jats:italic>), bluegill sunfish (<jats:italic>Lepomis macrochirus</jats:italic>), and channel catfish (<jats:italic>Ictalurus punctatus</jats:italic>) have shown that more than 90% of suction power in high performance strikes comes from the axial musculature. Thus, the shape of the axial muscles and skeleton may impact suction feeding mechanics. Royal knifefish (<jats:italic>Chitala blanci</jats:italic>) have an unusual postcranial morphology, with a ventrally flexed vertebral column and relatively large mass of epaxial muscle. Based on their body shape, we hypothesized that royal knifefish would generate high power strikes by utilizing large neurocranial elevation, vertebral column extension, and epaxial shortening. As predicted, <jats:italic>C. blanci</jats:italic> generated high suction expansion power compared to the other three species studied to date (up to 160 W), which was achieved by increasing both the rate of volume change and the intraoral subambient pressure. The large epaxial muscle (25% of body mass) shortened at high velocities to produce large neurocranial elevation and vertebral extension (up to 41 deg, combined), as well as high muscle mass-specific power (up to 800 W kg<jats:sup>-1</jats:sup>). For the highest power strikes, axial muscles generated 95% of the power, and 64% of the axial muscle mass consisted of the epaxial muscles. The epaxial-dominated suction expansion of royal knifefish supports our hypothesis that postcranial morphology may be a strong predictor of suction feeding biomechanics.</jats:p><jats:sec><jats:title>SUMMARY STATEMENT</jats:title><jats:p>Royal knifefish rely on their distinct postcranial morphology--with a curved vertebral column and large dorsal body muscles--to produce large neurocranial elevation and powerful suction feeding.</jats:p></jats:sec>

Item Type: Preprint
Uncontrolled Keywords: 30 Agricultural, Veterinary and Food Sciences, 3005 Fisheries Sciences
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Life Courses and Medical Sciences
Depositing User: Symplectic Admin
Date Deposited: 17 May 2022 09:54
Last Modified: 21 Jun 2024 09:48
DOI: 10.1101/2022.01.17.476172
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