Taxonomy and phylogenetics of the Synalpheus paraneptunus-species-complex (Decapoda: Alpheidae), with a description of two new species

Abstract

The species-complex of Synalpheus paraneptunusCoutière, 1909 is one of the most behaviorally and sexually diverse groups of sponge-dwelling shrimp in Synalpheus, containing both eusocial and pair-living species. Accurate resolution of this taxonomically challenging group is crucial to examining the evolution of social behavior in the genus. New collections from the US Florida Keys and Cuba, along with examination of previous collections from Jamaica, Panama and Belize, have yielded two new species: the eusocial Synalpheus cayoneptunusn. sp. (described from type material from the Florida Keys), and Synalpheus ankerin. sp. (described from type material from Belize). Synalpheus duffyiAnker and Tóth, 2008 is reported from new locations in Cuba and the Florida Keys. A phylogenetic analysis of six of the nine species in the S. paraneptunus-species-complex indicates that eusociality likely arose only once in this complex but was secondarily lost in the pair-living species S. ankeri. A key to the nine known species in the complex is presented based on morphological characters.