DOI: 10.5061/dryad.2280gb5qh
title: Unprecedented biting performance in herbivorous fish: how the complex biting system of Pomacentridae circumvents performance trade-offs

description: It is well accepted that the complexity of functional systems may mitigate
 performance trade-offs. However, data supporting this theory is hard to
 find because it needs to be based on a functional system with different
 complexity levels in closely-related species. The Pomacentridae
 (damselfishes) provide an excellent opportunity to test the hypothesis
 because most of the species have two mouth-closing systems: the first
 using the adductor mandibulae, as in all teleost fishes, and a second one
 relying on the cerato-mandibular ligament (cmd), a synapomorphic trait of
 the family. Interestingly, some pomacentrids have secondarily lost the cmd
 ligament during evolution and therefore have a less complex mouth-closing
 system. Using dissection, kinematic analysis, and mathematical modeling,
 we demonstrated that the possession of two mouth-closing systems enabled
 grazing damselfishes to have a forceful and extremely fast bite. This
 combination challenges a major functional trade-off in fish jaw dynamics,
 as systems better suited for force transmission are usually less suited
 for speed transmission, and vice versa. The combination of grazing
 behavior, small and robust lower jaws (conferring high biting force), and
 an ultra-fast bite is unusual within actinopterygians. These attributes
 and their associated performance seem to be required conditions to
 colonize the ecological niche of farming, i.e., the maintenance of small
 filamentous algae crops serving as both food and storage.
description: Raw data: The dataset
 contains four tables with the raw data of the study (excel file tables
 S1-S4). I) The table S1 contains the mouth closing
 force and speed in various species of Pomacentridae. The force and
 velocity have been measured thanks to a dynamic biomechanical model. For
 more details about how the model works see: Van Wassenbergh, S., P. Aerts,
 D. Adriaens, and A. Herrel. 2005. A dynamic model of mouth closing
 movements in clariid catfishes: the role of enlarged jaw adductors.
 Journal of Theoretical Biology 234: 49-65. Doi:
 10.1016/j.jtbi.2004.11.007. Different groups were
 compared, the "Group 1" variable opposes the grazing to the
 non-grazing species, and the "Group 2" variable opposes the
 species with and without the cerato-mandibular ligament.
 To calculate the mouth closing force and speed with the
 biomechanical model, sixteen variables were measured by dissection on the
 specimens. See the study abovecited for more details about each
 variable.  II) The table S2 contains the mouth closing
 speed measured <em>in vivo</em> in various species of
 Pomacentridae thanks to a high-speed camera (500 to 1000 fps).
 III) The table S3 contains the mouth closing speed and duration
 in various species of actinopterygians. These data were collected from the
 literature, the references are indicated below the table. For each
 species, the proportions of nekton and hard item preys in their diet habit
 are indicated. These latter data were collected from Fishbase.
 IV) The table S4 contains the closing mechanical advantage (MA
 closing) in various species of actinopterygians. These data were collected
 from the literature, the references are indicated below the table. For
 each species, the proportions of nekton and hard item preys in their diet
 habit are indicated. These latter data were collected from
 Fishbase. Supplemental
 tables: Two supplemental tables are also
 provided (word file tables S5-S6) and give additional information to the
 table 1 and 2 published in the study in The American Naturalist.
description: The R-code to run all the analyses of the study (using the raw
 data in the tables S1-S4) is provided. A .tree file
 corresponding to the phylogenetic tree of the 29 species of Pomacentridae
 investigated is also provided as necessary to run the
 phylogenetic-corrected analyses.