Notopontonia platycheles, a Little-Known Shallow-Water Shrimp from Western Australia (Decapoda: Pontoniinae)

Abstract

ABSTRACT The discovery of the red-lipped sea squirt Herdmania momus, as the host species for Notopontonia platycheles from the southern coast of Western Australia made it possible to confirm and add to the original species description. The shape of the large flattened chela of the second pereiopods is shown to be an ontogenetic development in both males and females. The final shape is accomplished with an increased growth of the ventral carina. The shrimp is a temperate species that extends it distribution up to Shark Bay (about 26°S) on the western coast of Australia. The majority of host tunicates were found with a single individual of N. platycheles inside, contrary to the usual situation of associated shrimps living in pairs. The shrimp often shares the branchial chamber of its host with other decapod crustaceans, indicating that it may migrate out of or between the host tunicates. In some tunicates at Shark Bay, a few specimens of Dasella ansoni were found. This is the first discovery of this species since the type specimens were found in the Arafura Sea.