Molecular Identification of Mid to Final Stage Slipper Lobster Phyllosoma Larvae of the Genus Chelarctus (Crustacea: Decapoda: Scyllaridae) Collected in the Pacific with Descriptions of Their Larval Morphology.

Morphological descriptions of phyllosoma larvae are essential for correct species identification and investigating the spatiotemporal distribution and recruitment process of spiny and slipper lobsters. Species identification of the phyllosoma larvae in the Scyllarinae subfamily is particularly difficult because of the morphological similarities among species and the scarcity of morphological information describing correct species identity. We extracted mid-to final-stage (V to VIII) phyllosoma larvae (n = 12) belonging to the subfamily Scyllarinae from several plankton samples collected in the Pacific and then performed molecular species identification using mitochondrial DNA COI and 16S rDNA sequence analyses. Three larvae collected around the Ryukyu Archipelago were identified as Chelarctus aureus (stage VI to VIII), and four collected around the Ryukyu Archipelago and Ogasawara Islands were identified as C. virgosus (V to VIII). One larva (V) collected in the central South Pacific was determined to be a subspecies of C. crosnieri. DNA barcodes could not be made for the remaining four larvae (V to VIII) collected around the Ryukyu Archipelago (designated by ?Chelarctus sp-1). Based on the morphological characteristics of the C. virgosus phyllosoma described in this study and the adult distributions reported to date, C. cultrifer phyllosomas previously reported in Japanese and Taiwanese waters are likely to be C. virgosus. This paper also presents a set of diagnostic morphological characteristics that can be used to discriminate among these four species of Chelarctus and from other genera in the subfamily Scyllarinae.