A New Species of the Mud Shrimp Genus Axianassa (Crustacea: Decapoda: Gebiidea: Axianassidae) from Japan

A new species of mud shrimp, Axianassa japonica (Gebiidea: Axianassidae), is described and illustrated on the basis of a single male specimen from Kushimoto, Wakayama Prefecture, Japan, collected at a depth of 15 m. It represents the first record of the genus from Japanese waters. Of the nine congeneric species it appears closest to A. heardi Anker, 2011, known from Queensland, Australia. The presence of two pairs of short longitudinal carinae on the anterior part of the carapace, the ventrally blunt pleuron of the first pleomere, and the presence of an incomplete suture on the uropodal endopod immediately distinguish the new species from A. heardi. The status of Axianassidae is briefly discussed, and an identification key to the species of Axianassa is provided.