DOI: 10.5061/dryad.gv3r544
title: Data from: Functional coupling in the evolution of suction feeding and gill ventilation of sculpins (Perciformes: Cottoidei)

description: Suction feeding and gill ventilation in teleosts are functionally coupled,
 meaning that there is an overlap in the structures involved with both
 functions. Functional coupling is one type of morphological integration, a
 term that broadly refers to any covariation, correlation, or coordination
 among structures. Suction feeding and gill ventilation exhibit other types
 of morphological integration, including functional coordination (a
 tendency of structures to work together to perform a function) and
 evolutionary integration (a tendency of structures to covary in size or
 shape across evolutionary history). Functional coupling, functional
 coordination, and evolutionary integration have each been proposed to
 limit morphological diversification to some extent. Yet teleosts show
 extraordinary cranial diversity, suggesting that there are mechanisms
 within some teleost clades that promote morphological diversification,
 even within the highly integrated suction feeding and gill ventilatory
 systems. To investigate this, we quantified evolutionary integration among
 four mechanical units associated with suction feeding and gill ventilation
 in a diverse clade of benthic, primarily suction-feeding fishes
 (Cottoidei; sculpins and relatives). We reconstructed cottoid phylogeny
 using molecular data from 108 species, and obtained 24 linear measurements
 of four mechanical units (jaws, hyoid, opercular bones, and branchiostegal
 rays) from micro-CT reconstructions of 44 cottoids and one outgroup taxon.
 We tested for evolutionary correlation and covariation among the four
 mechanical units using phylogenetically corrected principal component
 analysis to reduce the dimensionality of measurements for each unit,
 followed by correlating phylogenetically independent contrasts and
 computing phylogenetic generalized least squares models from the first
 principle component axis of each of the four mechanical units. The jaws,
 opercular bones, and branchiostegal rays show evolutionary integration,
 but the hyoid is not positively integrated with these units. To examine
 these results in an ecomorphological context, we used published ecological
 data in phylogenetic ANOVA models to demonstrate that the jaw is larger in
 fishes that eat elusive or grasping prey (e.g., prey that can easily
 escape or cling to the substrate) and that the hyoid is smaller in
 intertidal and hypoxia-tolerant sculpins. Within Cottoidei, the relatively
 independent evolution of the hyoid likely has reduced limitations on
 morphological evolution within the highly morphologically integrated
 suction feeding and gill ventilatory systems.
description: Trees, data files, and R
 scriptbesttree_icz022.tree =
 maximum clade credibility tree from best MrBayes run; cottoidei.run1.t =
 posterior distribution of trees from best MrBayes run; Functional Couping
 Stats icz022.R = R Script for all analyses in this study;
 ctdata_icz022.txt = morphological measurements from micro-CT scans of 45
 species; CSV files = ecological dataicz022_dryad.zip