A new leptostraca: Nebalia terazakii

Illustration from original publication

Leptostraca is an order of small, marine crustaceans which is believed to be the most primitive group of  its class, the Malacostraca as some species first appear in the fossil record during the Cambrian period. These crustaceans are unique in having their carapace compressed to such an extent that it forms a mussel-like shell held together by a strong adductor muscle. The new representative was found during a study on the biodiversity of the marine invertebrate fauna around Malaysia.

The new species was named after the late Professor Dr. Makoto Terazaki, from the University of Tokyo.

For the experts: A new species of Leptostraca, Nebalia terazakii sp. n. is described and figured. The species was sampled from the coral reefs of Pulau Payar Marine Park, Langkawi, Malaysia. There are 32 existing species of Nebalia but Nebalia terazakii sp. n. can be distinguished from the other known species of Nebalia by the following combination of characters: the rostrum is 1.89 times as long as wide and the eyes have no dorsal papilla or lobes. Article 4 of the antennular peduncle has one short thick distal spine. The proximal article of the endopod of maxilla 2 is shorter than the distal, a feature peculiar to Nebalia terazakii sp. n., the exopod of maxilla 2 is longer than article 1 of the endopod, the posterior dorsal borders of the pleonites 6 to 7 are provided with distally sharp denticles, anal plate with prominent lateral shoulder and finally, the terminal seta of the caudal rami is 1.17 times the length of the entire rami.