Six new species of aglajid opisthobranch mollusks from the tropical Indo-Pacific

Abstract

Six new species of aglajid opisthobranchs are described from various localities in the tropical Indo-Pacific. Philinopsis falciphallus n. sp., found from the Marshall Islands to the Red Sea, is distinguished by its reddish body color, a distinct black or maroon longitudinal line on the foot, a posterior projection on the posterior shield and a penis with a chitinous, sickle-shaped spine and numerous smaller spines. Philinopsis coronata n. sp., known only from the Philippines, is similar to P. falciphallus but dominated by yellow body color and a ventral surface of the foot with yellow and maroon spots. It has a trumpet-shaped penis with a crown of rounded tubercles on the apex and anterior and posterior zones of penial spines. Philinopsis ctenophoraphaga n. sp. is found from the Philippines, Indonesia and the Red Sea. It feeds on platyctene ctenophores, including Coeloplana meteroris. It can be distinguished by its elongate posterior lobe of the headshield, reddish color with white spots, thinly muscularized buccal mass and simple, unarmed penis. Chelidonura mandroroa n. sp. is characterized by its black body with orange patches lined by yellow. It has a simple penis with a cuticularized apical papilla. This species has been found from Japan, Taiwan, the Philippines, Indonesia, Madagascar and Kenya. Chelidonura alisonae n. sp. is apparently restricted to the central and eastern Pacific of the Hawai’ian Islands, Johnston Island, the Marianas Islands and Easter Island. It is similar in coloration to C. hirundinina, but has orange lines on the dorsal and lateral shields and has a broad right posterior lobe rather than an acutely pointed one. The penis is simple and unarmed. Odontoglaja mosaica n. sp., found from the Indian Ocean of Madagascar and South Africa, differs from O. guamensis by possessing a reticulate pattern on the notum rather than a pattern of brown spots. It also has a shorter penial papilla that is bifurcate rather than undivided one.