Meeting Abstract

6-2  Thursday, Jan. 5 08:15 – 08:30  Molecular Phylogeny of the Alpheus “macrocheles” Species Group in the Tropical Western Atlantic Uncovers Undescribed Diversity SCIOLI, JA*; FELDER, DL; University of Louisiana, Lafayette; University of Louisiana, Lafayette jas0409@louisiana.edu

The genus Alpheus constitutes one of the most speciose genera of decapod crustaceans. A group of species related to A. macrocheles, one of seven species groups erected by Kim & Abele (1988), is united by teeth on the margins of the orbital hoods and a twisted, compressed major cheliped. This group presently includes eight species that occur in the western Atlantic. Several previous studies have suggested that one in particular, Alpheus amblyonyx, represents a species complex. We present a molecular phylogeny including four members of the “macrocheles” group. We utilized two mitochondrial genes, Cytochrome Oxidase I (COI) and 16S rRNA as well as nuclear marker Histone H3. Our results suggest that material identified to Alpheus amblyonyx constitutes two distinct clades, one of which is presently undescribed. The clade representing a likely new species included specimens exclusively from deeper Gulf of Mexico waters (42-246m), whereas Alpheus amblyonyx s.s. was collected from shallow water in the Caribbean. This potentially new species has morphological affinity to A. cedrici from Ascension Island, A. macrocheles, from the eastern Atlantic, and A. pouang, from Brazil. Present lack of comparable sequence data for these species for now limits study of their evolutionary relationships with the undescribed Gulf of Mexico clade. Further investigation of genetic relationships between members of the group worldwide is necessary to properly revise taxonomy and systematics of this alpheid complex.