First records of three Nematocarcinus species (Crustacea, Decapoda, Nematocarcinidae) in the deep-waters of the north-western Pacific.

Abstract

During two scientific expeditions in the South China Sea and the Kyushu-Palau Ridge area, several specimens of thread-leg shrimp were collected from deep waters. Amongst them, three species, Nematocarcinusevansi Burukovsky, 2000, N.exilis (Spence Bate, 1888) and N.machaerophorus Burukovsky, 2003 were newly recorded from the north-western Pacific. The morphological features of these specimens are in concordance with the original description. Nematocarcinusevansi and N.machaerophorus were recorded for the second time since their original descriptions and newly found from the South China Sea. Nematocarcinusexilis, collected from the Kyushu-Palau Ridge area, represents a great distribution expansion from the eastern Atlantic and the Mediterranean to the Pacific, making it the fourth Atlantic-Pacific distributed Nematocarcinus species. Their detailed morphological characteristics, colour patterns and partial sequences of the COI and 16S rRNA genes are provided, respectively.