OKINAWAN
OPISTHOBRANCH OF THE WEEK

Hypselodoris babai Gosliner & Behrens, 2000 (notum: 39mm)
{paratype specimen, deposited at California Academy of Sciences / CASIZ 127924}

Opisthobranch of the Week Data

Taxonomy:

Frequency on Okinawa: Collection Data:
[brackets indicate range for all Okinawa-collected specimens of the species]


Species Account:

        Hypselodoris babai is considered to be very rare on Okinawa as I have seen and collected a total of only three individuals (the first was collected in April of 1996, the second in April of 1997, and the most recently collected animal, in May of 2000). I've included three addition images of the above featured animal as well as images of the two earlier collected animals which are designated as the holotype and one of the two paratype specimens (Gosliner & Behrens, 2000). The above featured animal was collected, actually nearly uncollected, while making a traverse across a large patch of Caulerpa lentillifera, while making an ascent from a deep dive. The animal was found crawling amid a relatively large (approx. 15m sq.) population of the above alga; this particular area is an ecotone between a large area of open sand and strewn coral rubble. It's interesting to note that all three of the specimens were found crawling in the open amid relatively dense growths of this alga. When this third animal was found, it was immediately picked up and placed into a zip-loc bag, or at least so I had thought. Apparently the level of nitrogen [grin] from the deeper portion of the dive allowed me to misjudge placing the animal into the collecting bag, and when I attempted to inspect the newly found treasure a few moments later, it wasn't where I thought it had been placed. I immediately back-tracked my route, but by now there was swirling silt covering the earlier route, making the bottom almost totally obscured by the silt. I put my faceplate near the bottom and began a systematic back and forth search . . . by this time my maximum allowed bottom time was being seriously challenged and I decided to abort the search. A few seconds later I found and properly bagged the lost chromodorid which was indeed a stroke of luck. I very seldom lose specimens, but when I do, especially with an undescribed animal such as this was at the time, it really ruins my day.

        This is one of the two most recently named Hypselodoris species by Gosliner & Behrens (2000). This beautiful animal was named in honor of the Japanese opisthobranch researcher, Kikutaro Baba. Dr. Baba has been a prolific writer involved with the description of Japanese opisthobranchs for more than 70 years. The following from Bertsch (1993) gives one some idea of just how prolific Dr. Baba's writing has been:

Dr. Baba has published segments in 19 books in Japanese, more than 50 miscellaneous notes and papers in Japanese, 55 articles in the Japanese aquarist magazine Collecting and Breeding, and more than 120 papers in English.

        The above featured animal is one of thirteen described species of Hypselodoris found in Okinawan waters. The thirteen species identified to date (July, 2011) are: