OKINAWAN
OPISTHOBRANCH OF THE WEEK

Opisthobranch of the Week Data

Taxonomy:

        Chelidonura hirundinina is considered to be common, although quite seasonal on Okinawa. Although I have collected only fifteen individuals since mid-February of 1989, many additional animals have been seen. I can't be certain in terms of the peak population densities as accurate records have not been maintained, but it would appear that the animals are more commonly found here during the early warmer months of the year, i.e., June and July. I have distinct recollections that these animals have been observed in relatively high densities (several per meter square) actively crawling on the substrate in areas of mixed sand/coral rubble associated with spur and groove formations of stony coral reefs.

        This terribly attractive small cephalaspid is quite variable in color, but the "T" shaped marking on the head (usually more pronounced than in the featured animal above) serves to distinguish the animal from any others found here on Okinawa.