Hundt, Peter2017-10-092017-10-092016-06https://hdl.handle.net/11299/190557University of Minnesota Ph.D. dissertation.June 2016. Major: Conservation Biology. Advisor: Andrew Simons. 1 computer file (PDF); vi, 91 pages.This research examines the evolution of diet, trophic morphologies and habitat transitions in combtooth blennies. Blennies are small marine fishes found in many different habitats through out the tropics and temperate zones. Chapter 1 provided the first molecular phylogeny of blennies and used it to explore the evolution of habitat association and transitions. This highly resolved and thoroughly sampled blenniid phylogeny redefines the taxonomy of the group and supports the use of 13 unranked clades for the classification of blenniids. Ancestral state reconstructions identified four independent invasions of intertidal habitats and subsequent invasions into supralittoral and freshwater habitats from these groups. In chapter 2 I describe the diet of 30 blenny species from Japan. Blennies were divided into seven feeding groups: omnivores, herbivores, detritivores, molluscivores, corallivores, worm-like invertebrate feeders, and fish mucus/scale/ray feeders. The largest cluster, detritivores, contained 17 blenny species from all habitat zones and both climate zones. The findings suggest closely related species fill similar feeding niches and detritus is an important component of many blenny diets. Chapter three examines the evolution of trophic morphology and diet using more through well-sampled phylogeny (142 species), diet data (130 species) and morphological data (118 species). Results strongly suggested that numerous, thin, blunt, flexible, and long teeth with narrow spacing is correlated with a diet consisting largely of detritus. Despite their position at a morphological extreme of teleost tooth morphology, the long teeth of blennies still exhibit substantial, measurable variation in tooth shape, count, and attachment, as well as substantial variation in diet.enThesis or Dissertation