A New Species of Chelorchestia (Amphipoda: Talitridae) from Southwest Florida, with Comments on Other Species Within the Genus

Amphipods in the genus Chelorchestia are inhabitants of marshes and semiterrestrial environments of principally tropical regions of the world. Only three species are currently assigned to the genus but many undescribed species apparently exist. Along the coasts of Florida and Louisiana populations of Chelorchestia have been known for some time, all presumably representing undescribed species. A population recently discovered living in oligohaline/freshwater swale habitat on Sanibel Island, Florida, has been compared with the two other described species and differs in several consistent ways, principally in the combination of fewer articles of the flagellum of antenna 2, short pereopods 3-5, absence of pellucid lobes on the female gnathopod 1, and the structure of the propod and dactyl of the male gnathopod 2. Notes on the other two species, C. costaricana (Stebbing, 1906) and C. vaggala (Bowman, 1977) are provided. Observations on other possibly conspecific populations of the new species occurring along the Gulf coasts of Florida, Alabama, Louisiana, Mississippi, and Texas and another undescribed species occurring in southeastern Florida are presented and discussed