Genetic divergence of Argis lar and A. hozawai, distinct sibling species of deep-sea crangonid shrimp from the Sea of Japan

Abstract

Argis lar and A. hozawai are commercially important deep-sea crangonid shrimps of closely similar morphology. A previous study described three morphological characters to distinguish A. lar and A. hozawai was based on comparison of specimens of different size, raising the possibility that these characters are features of intraspecific differences related to body size. In the present study, mitochondrial DNA fragments encoding the cytochrome oxidase subunit I (COI) gene were sequenced in order to reassess the morphological criteria purported to separate A. lar and A. hozawai, based on specimens collected under a synchronous and sympatric sampling design. Two distinct clades were detected (p-distance 7.72%) supported by high bootstrap values, which completely correspond to A. lar and A. hozawai identified by morphological characters. Accordingly, A. lar and A. hozawai should be treated as two distinct species for appropriate fisheries management. © The Plankton Society of Japan.