Species Diversity

Abstract

Paragrandidierella (Crustacea: Amphipoda: Aoridae) is reinstated for three species from Japan, P. minima Ariyama, 2002, P. unidentata (Ren, 2006), and P. urauchiensis sp. nov. Eight morphological features distinguish these species from species of the genus Grandidierella, with which Paragrandidierella was synonymized. Paragrandidierella urauchiensis sp. nov. was collected from a tidal flat at the mouth of the Urauchi River, Iriomote Island, Okinawa Prefecture. This new species has long antennae and a long, acute tooth on the posterodistal corner of the gnathopod 1 carpus in males. Paragrandidierella unidentata was collected from a tidal flat at the mouth of the Waka River, Wakayama Prefecture, as the first record of this species in Japan. It is characterized by a short antenna 2 and a short tooth on the posterodistal corner of the gnathopod 1 carpus in males. The morphology of the antennae, the detailed structure of the mouthparts, and the change in shape with growth of P. minima, the type species of the genus, are also described. A key to the species of the genus is provided.