Meeting Abstract
Fish gills are composed of elongate gill filaments that support microscopic gill lamellae, which are the primary site of gas and ion exchange. To understand how the morphology of these complex three-dimensional structures evolve within clades of closely-related fishes, especially in response to ecological and physiological demands, we studied the sculpins (superfamily Cottoidea). Sculpins are found in freshwater and marine habitats, and marine species can be found in the intertidal, subtidal, or deep-sea. We examined 12 sculpin species from the Pacific Northwest using scanning electron microscopy to take six measurements of the gill microstructures that capture the variation in their complex branching shape. We used phylogenetically corrected ANOVAs to test for relationships among our six measurements and two ecological parameters (tendency to be found in the intertidal and to exhibit air-breathing). We found no significant relationship among these morphological and ecological variables. However, a phylogenetically corrected principal component analysis revealed that strictly subtidal fishes occupy a morphospace defined by shorter gill filaments and shorter lamellae.
