Meeting Abstract

33.7  Friday, Jan. 4  Phylogeny of the brachyuran crab superfamily Majoidea: a comparison of molecular and morphological characters HULTGREN, K.M.*; PALERO, F.; GUERAO, G.; MARQUES, F.P.L.; Smithsonian Institution; University of Barcelona; University of Barcelona; University of San Paulo, Brazil khultgren@ucdavis.edu

Phylogenies are invaluable tools to trace the evolution of morphological, behavioral, and physiological diversity in decapod crustaceans. Here we compare a recent molecular phylogeny of the superfamily Majoidea to phylogenies based on larval morphology, to evaluate the utility of combined molecular-morphological datasets in inferring relationships among majoid families. Larval morphology and molecular characters for over 15 genera (and seven families) of majoids supported similar relationships, including a monophyletic clade of species from the family Oregoniidae branching at the base of the Majoidea, and a close association between species in the Pisidae and the Epialtidae. However, larval-morphology and molecular datasets were not strictly congruent with adult morphology, i.e. both found evidence for paraphyly of some majoid families. In order to investigate broad patterns in the evolution of predator defense behavior in this group, we also mapped variation in morphology related to camouflage behavior (hooked setae used for decoration camouflage). We found that losses of decoration occur in several distinct portions of the tree, suggesting decoration camouflage may be a labile trait in this group and an ideal character for examining the evolution of predator defenses in brachyurans.