Opisthobranch of the Week Data
Trapania vitta is considered to be very rare in Okinawan waters; I've not seen the animal here on Okinawa's main island although I've previously featured several members of the genus from Okinawan waters (included in list below). Atsushi mentions (pers. comm.) seeing only the single above featured animal in the Keramas* and of course considers the species to be very rare here. T. vitta was in the past listed on these pages as T. aurata Rudman, 1987, but with publication of the recent Gosliner & Fahey (2008) paper I've now changed the name.
The following is taken from Gosliner & Fahey (2008):
This species has been reported from Okinawa, Bali, Indonesia, Papua New Guinea, the Philippine Islands (Gosliner & Fahey, 2008.) and the Kerama Islands (Ono, 1999).
The living animals range from 2-5mm long. The body shape is elongate and convex, without a distinct notal margin. The body is widest in the branchial region. The head is rounded anteriorly and the anterior foot margin is extended into elongate tentacles. The oral tentacles are relatively short and stout with a rounded apex. The posterior end of the foot is sharply tapered with a somewhat rounded posterior tip. The non-retractile, perfoliate rhinophores are relatively short with 6-7 lamellae. The stalk and the apex are similar in thickness. The extra-rhinophoral appendages are relatively short, thin and have a curved apex. The gill consists of three bipinnate branches. The extra-branchial appendages are curved, about the same size as the extra-rhinophoral appendages. The body is entirely white. The anterior foot margin tentacles are white. The oral tentacles are reddish-brown or orange. The extrarhinophoral and extra-branchial appendages are white. The rhinophores are white with a reddish-brown or orange line on the upper portion of the anterior side. The gill leaves are also white with the same reddish-brown or orange lines on the rhachis. The posterior tip of the foot has blue-grey pigment with an occasional orange pigment spot.
Previously I've featured several members of the genus Trapania on these pages and as of the current date, there are several described species reported from Okinawan waters. The featured animals are as follows:
T. euryeia T. gibbera T. naeva T. squama T. toddi T. vitta the above featured animal
* Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.