New species of Ampithoe Leach, 1814 from Todos-os-Santos Bay, Bahia State, Brazil.

Ampithoe is one of the most diverse genera of Ampithoidae, commonly found in shallow waters associated with algae. This genus is distinguished by the absence of antenna 1 accessory flagellum, pereopods 5–7 not prehensile and uropod 1 spur absent. From Brazil, only four species are hitherto known, which are A. thaix, A. robustimana, A. ramondi and A. marcuzzii. In the present study, we describe a new species of Ampithoe from Todos-os-Santos Bay, Northeastern Brazil, found associated with the sponge Clathria. The new species is unique by showing mandibular palp thin and reduced, male gnathopod 1 propodus palm very short and setose, male gnathopod 2 propodus palm acute, with a tooth near hinge of dactylus. A taxonomic key to Ampithoe of the world is provided. [ABSTRACT FROM AUTHOR]