First Record of Hemichela nanhaiensis (Pycnogonida: Ammotheidae) from Japanese Waters, with the First Description of Females

Abstract

We report the first record of the ammotheid pycnogonid species Hemichela nanhaiensis Wang et al., 2015, from Japanese waters. Four specimens of H. nanhaiensis were collected from the East China Sea at depths of 405–635 m, including the first females ever found. We redescribe male and female H. nanhaiensis from these specimens. We found that H. nanhaiensis is sexually dimorphic in the number of tiny lateral outgrowths on the lateral processes; length of the lateral process tubercles and oviger articles 4 and 5; ratio of the terminal claw to article 10 in the oviger; presence or absence of a proximal reversed spine on oviger article 5; thickness of the leg femur; and number of gonopores.