A new genus of the family Alpheidae is established, based on a new species from Japanese waters. Cavipelta yamashitai n.g., n.sp. is characterized by having a sinus on the lower margin of the carapace in both sexes and a flap-like processes on the exopod of the uropod in large males. It also bears a robust and thickened antennal flagellum and a mesially curved chela of the first pereopod in large males. C. yamashitai was usually collected from burrowes of thalassinids. The systematic position of the new genus is discussed and the biology of the new species is briefly presented.
Crustacea, Decapoda, Alpheidae, Cavipelta, new genus, new species, Pacific Ocean.