A new species of the mud shrimp genus Axianassa Schmitt, 1924 (Decapoda: Gebiidea: Laomediidae) from Japan.

The laomediid mud shrimp genus Axianassa Schmitt, 1924 is currently represented by 12 species worldwide. In this study, a new species of the genus, A. microlepis, is described and illustrated on the basis of two female specimens obtained from Awaji Island, eastern part of the Seto Inland Sea, Japan, at depth of 8 m. The type specimens were collected by means of an airlift suction sampler, which enables collection of infauna in subtidal soft sediments. The new species, representing the fourth species of the genus known from the western Pacific, is readily distinguished from other congeners by the unique structure of the antennal scaphocerite (short, non-dagger shaped, terminally rounded or having spine and blade), faintly crenulate rostral margins and the presence of a small lateral notch on the uropodal endopod. An amended identification key to the species of Axianassa and Heteroaxianassa Sakai, 2016 is provided.