OKINAWAN
OPISTHOBRANCH OF THE WEEK

Opisthobranch of the Week Data

Taxonomy:

        Ceratosoma tenue is considered to be uncommon on Okinawa; I've collected nine individuals to date, but I've seen and/or photographed perhaps an additional two or three others which were not collected.

        Another similar appearing species of Ceratosoma found here is C. trilobatum, which is found in roughly the same frequency (remarkably, I've collected the same number of both species, nine), although my experience has been to find it on Okinawa more commonly in shallower waters than C. tenue. The prominent median horn rising posterior of the gills on both Okinawan species produces similar appearing animals but they are usually quite readily separated from each other by the single pair of prominent lateral projections located near the gills of C. trilobatum; in the case of C. tenue there are two sets of lateral projections. Both of the species seem to exhibit quite a bit of color variation.