Anchialine adjustments: an updated phylogeny and classification for the family Barbouriidae Christoffersen, 1987 (Decapoda: Caridea)

Barbouriidae Christoffersen, 1987 is a family comprised of 4 genera and 11 species of enigmatic shrimps restricted to anchialine or marine caves whose evolutionary history and relationships remain elusive. We investigated the evolutionary relationships among members of Barbouriidae with the inclusion of four genera and nine species, and newly collected material from Belize, the Bahamas, and the Yucatán Peninsula, Mexico. Phylogenetic analyses based on seven mitochondrial and nuclear gene regions and genetic distances calculated using partial 16S gene regions have identified a need to revisit the relationships and classification within Barbouriidae. More specifically, we find evidence to suggest Janicea Manning & Hart, 1984 as a junior synonym of Parhippolyte Borradaile, 1900, B. yanezi Mejía, Zarza & López, 2008 as a synonym of Barbouria cubensis (von Martens, 1872), and define two new subfamilies, Calliasmatinae Holthuis, 1973 and Barbouriinae Christoffersen, 1987. Included is a dichotomous key for the species of Barbouriidae that summarizes previous literature and includes new morphological characters. Our findings shed light on existing inaccuracies and gaps in molecular data from barbouriids. We also provide further clarity into evolutionary relationships among genera of Barbouriidae and their allies, suggesting phylogeographic divisions within the family. Our findings suggest an early Atlantic-Pacific divide among genera originating from a shallow-water reef ancestor.