A new species of Amphictene (Annelida, Polychaeta, Pectinariidae) from sandy shore of Okinawa, Japan

Abstract

We described here a new species of Amphictene (Annelida, Polychaeta, Pectinariidae) from the sandy shore of Kouri-jima, Nakijin, Okinawa, Japan. Amphictene nakijin sp. nov. is characterized by the following characters: an anterior dorsal lobe on segment 2; ventro-median lobes on segments 3–5; anterior conical or rounded lappets on the ventro-lateral lobe of segment 2; lateral ear-like lobes on segment 4; slender dorso-lateral pads on segments 3 and 4; an inflated ventro-lateral lobe on segment 6; 17 segments with notopodial chaetae and 13 segments bearing uncini on neuropodia; neuropodial uncini with 2–3 rows and 10–13 columns of teeth, with both distal and basal teeth small; 9–10 pairs of weakly curved scaphal hooks; and the scaphe that is deeply furrowed posteriorly and with a short anal flap. We also obtained a mitochondrial 16S rRNA gene sequence of this new species to serve as a reference for future studies.