Opisthobranch of the Week Data
Volvatella sp. 1 is considered to be rare in the waters of Okinawa's main island; five individuals have been collected from the same locale on three separate dates. The above featured animal was found crawling amid a relatively large, dense colony of a green thallophyte, Caulerpa sp., and when the animal was touched it immediately exuded an apparent white wispy substance into the surrounding water. I've previously featured two described species of Volvatella from Okinawan waters on these pages, V. angeliniana & V. ayakii. In addition, I've added a second page with additional images of Volvatella sp. 1, including V. angeliniana.
Several specimens of Volvatella sp. 1 have been found in the same alga collection (Caulerpa sp.) along with V. angeliniana. The animals were discovered as they were "washed out" of a sorting pan containing the alga later at home. The animals were photographed during the years 1991 & 1992 and unfortunately the images currently available for this animal are relatively poor; size was not recorded for four of the specimens (one was found to be ca. 3mm). Ichikawa (1993) found two additional Volvatella in waters of the southern Ryukyu Islands (Kuro Island): 1) Volvatella viridis, described by Hamatani (1976) from Japan, and 2), an undescribed species, but different from the above featured animal.