Systematics of the shrimp genus Atya (Decapoda, Atyidae) in the light of multigene-based phylogenetic and species delimitation inference

The Atya genus classification is mostly stabilized, comprising 13 species in the Americas and West Africa. However, nearly 40 years have passed since its last revision. Some taxonomic questions remained due to morphological uncertainty, and new ones have been raised with molecular Atyidae phylogenies. The aim of this study was to conduct the first Atya molecular systematic assessment, verifying the taxonomic status of A. gabonensis, A. innocous, A. margaritacea and A. scabra. Gene fragments (16S, COI and H3) were obtained by DNA sequencing and used for genetic distance, phylogeny and species delimitation analyses (ABGD, PTP and GMYC). Our data corroborate A. gabonensis as a species with amphi-Atlantic distribution and suggest the use of A. innocous for specimens of the Caribbean Sea. We revalidated A. tenella Smith, 1871 for specimens from Pacific. Atya margaritacea, distributed along the Pacific coast of the Americas, was considered a valid and distinct species from A. scabra, which is distributed in the Atlantic and Pacific coasts of the Americas and West Africa; moreover, maybe this wide distribution belongs to a distinct species, being A. scabra restricted to Gulf of Mexico lineage. We corroborated the genus as monophyletic and highlighted remaining systematic issues. Overall, our multigene-based phylogeny and species delimitation analyses suggest that Atya comprises 14 species. This study provides data for future studies on the biodiversity, evolution and conservation of freshwater Atyidae shrimps and Neotropical fauna.

Automated summary

The Atya genus classification is mostly stabilized with 13 species in the Americas and West Africa, but some taxonomic questions remain. Through the first Atya molecular systematic assessment, several species have been verified and further research directions have been proposed.