Meeting Abstract

41.2  Friday, Jan. 4  The evolutionary relationship of gall crabs (family Cryptochiridae) and their placement within the Brachyura WETZER, R.*; ELWELL, S.L.; MARTIN, J.W.; Natural History Museum of Los Angeles Co.; Harvard University, Cambridge; Natural History Museum of Los Angeles Co. rwetzer@nhm.org

Crabs of the family Cryptochiridae are among the most unusual of all groups of decapod crustaceans. Little is known about their biology and natural history, but it appears that young female crabs settle on hermatypic corals and somehow induce the coral to grow over and around the young crab. For some cryptochirid species, the result is merely a protective indentation or crevice within the coral, but for other species the coral forms a �gall� completely encapsulating the crab and imprisioning it for the remainder of its life. Males are smaller than females and are believed to roam freely, searching for coral-entombed females. There are 20 genera with approximately 43 described species. They occur on scleractinian coral reefs worldwide and are most diverse in the Indo-West Pacific. As a result of morphological adaptations to their specialized habitat, cryptochirids� have evolved small, squat, and sometimes amorphous bodies making morphology-based estimation of their phylogenetic relationships to other brachyurans extremely difficult. Indeed, the uncertainty of their affinities to other crabs based on morphology has resulted in their currently accepted classification in their own separate superfamily. We use molecular data to address evolutionary relationships of gall crabs to other brachyuran families.