Reappraisal of the Crangonyx floridanus species complex, with the description of a new species of Crangonyx Bate, 1859 (Amphipoda: Crangonyctidae) from northern Florida, USA

Abstract Crangonyx apalachee n. sp. Cannizzaro & Sawicki in Cannizzaro, Sisco & Sawicki, is described from Lake Jackson in Leon County, Florida, USA, a prairie lake that periodically drains through karst sinkholes during times of low rainfall. The new species occurs in tall grass along the lake’s shoreline. Molecular analyses of the nuclear 18S rDNA and 28S rDNA along with the mitochondrial 16S rDNA, combined with morphological analyses were used to delineate the population from closely related crangonyctids. The occurrence of C. apalacheen. sp. in Lake Jackson marks the fifth species to be described from the floridanus complex in Florida. Collections from other locations across north Florida suggest the presence of additional floridanus-complex species still to be described.