DESCRIPTION OF THE GHOST SHRIMP SERGIO-MERICEAE, A NEW SPECIES FROM SOUTH FLORIDA, WITH REEXAMINATION OF S-GUASSUTINGA (CRUSTACEA, DECAPODA, CALLIANASSIDAE)

Sergio mericeae is here described from intertidal sandflats of the Atlantic coast of Florida, where it shares habitats with Neocallichirus rathbunae and N. grandimana. This new species, formerly identified with the Brazilian species, Sergio guassutinga (until recently assigned to Neocallichirus), bears a strong resemblance to its Brazilian counterpart in body size, the unique dactylar dentition of the major chela, and most other morphological features. However, these apparent sibling species can be distinguished on the basis of body coloration and subtle but consistent differences in the third maxilliped and major cheliped. Immature specimens from Louisiana, Texas and Tamaulipas, Mexico, strongly resemble topotypic juveniles from Fort Pierce, Florida, and suggest that S. mericeae ranges into the western Gulf of Mexico.