Molecular phylogeography of Tumidotheres maculatus (Say, 1818) and Zaops ostreus (Say, 1817) (Crustacea: Decapoda: Pinnotheridae) in the western Atlantic, with description of a new species and synonymy of Epulotheres Manning, 1993

Abstract

ABSTRACTThe commensal crab genus Tumidotheres is reportedly represented along the western Atlantic coast by Tumidotheres maculatus, with populations distributed from temperate to tropical waters in North and South America. Western Atlantic populations of the related genus Zaops have been alternatively separated into the northern species Zaops ostreus and southern Zaops geddesi. We hypothesized that populations of T. maculatus comprised more than one species, much as currently accepted in Zaops. Molecular markers (COI, 16S-NADH1 complex, 12S, and histone 3) were used to infer relationships between sampled populations of Tumidotheres and Zaops. We found that most populations of Tumidotheres belonged to a single species, but that specimens from the western Caribbean Sea represented an undescribed congener, herewith described and named. Remarkably, all sequenced populations of Zaops were inseparable, leading us to question the validity of Z. geddesi as the southern counterpart of Z. ostreus. Though sequence analyses failed, we provisionally reassign Epulotheres angelae to the genus Zaops on the basis of morphological characters. Since Epulotheres is a monotypic genus, this synonymizes the genus with Zaops.