Opisthobranch of the Week Data
Philinopsis falciphallus is unknown from Okinawa's main island as of mid-September, 2011. The above featured animal is one which was photographed from an area between dead corals and rocks, off of Gahi Island, one of a series of islands in the Kerama Islands Group, which are located 30 ~ 40 kilometers west of the Okinawa capitol, Naha. This featured animal was photographed by Atsushi Ono during November of 2010 in twenty-three meters of water. Atsushi's photograph is used here with his kind permission. It should be noted that Atsushi considers the species to be very rare in the Kerama Islands as he has seen only a single individual (pers. comm.).
The following information on the external morphology of Philinopsis falciphallus is taken from Gosliner (2011):
External morphology. The living animals are 9 to 25 mm in length and 5-12 mm wide. The general body color of the living animal is light pinkish to wine red with maroon with darker red pigment on the anterior portion of the head, along the parapodial margins and at the base of the posterior projection of the posterior shield. The entire dorsal and lateral surfaces of the body are ornamented with scattered irregular yellow spots and a few whitish patches. Specimens from the Marshall Islands (Johnson 2008) are much paler with dorsal and lateral whitish pigment and a few maroon spots on the head and parapodial margins. Small yellow to orange spots are also present over the body surface. The ventral surface of Philippine animals is pale pink to wine red with a midventral longitudinal maroon line and two additional more lateral lines that may be interrupted as maroon spots. The foot has a few large yellow spots scattered over the ventral surface. A similar pattern is found on the foot of the Marshall Island specimens and also those from Red Sea (Koretz 2005).
There are to date (mid-September, 2011) five species of Philinopsis reported from Okinawan waters. The five are:
Philinopsis falciphallus The above featured animal P. gardineri P. pilsbryi P. reticulata P. speciosa