Opisthobranch of the Week Data
Hallaxa paulinae is one of the more attractive of the Hallaxa species; certainly it's the most attractive of the five Okinawan species currently known from Okinawa (as of early August, 2004), which are:
H. cryptica H. hileenae H. indecora H. iju H. paulinae - the above featured animal
This attractive little actinocyclid is considered to be very rare on Okinawa as I have collected only three individuals (all three from the same locality and depth, a single day apart). Gosliner & Johnson (1994) named the species for Pauline Fiene-Severns who collected the type material of the species from Indonesia. The animal is also reported by Atsushi Ono in Bill Rudman's Sea Slug Forum as being found in the Kerama Islands (approximately 30km West of the Southern end of Okinawa), which, like Okinawa, are part of the Ryukyu Archipelago. *
Gosliner and Johnson (1994) point out the species was found on an unidentified white sponge, on which it was cryptic. It should be pointed out that the above featured Okinawan animals were not found on the orange demosponge as depicted in the photograph, but rather they were found within 20cm of each other, crawling on the surface of silty-sand with much strewn shell and rubble, beneath the pier. The third animal, collected from the previous day, was found in the same environment as the other two.
* Okinawa is the largest of approximately seventy-two islands making up the Ryukyu Archipelago which stretches for 600km.