Atys cylindrica
(Helbling, 1779)
Order: CEPHALASPIDEA
Family: Haminoeidae
DISTRIBUTION
Common Indo-West Pacific species.
PHOTO
Koumac, northern New Caledonia, October 1993. Animal 28mm long alive.
Atys is a herbivorous genus of shelled opisthobranchs related to Haminoea and Phanerophthalmus.
It is possible when more of the many tropical species are studied that they will be placed in other genera. At present most species are tropical and have heavy well-calcified shells. In most cases the true foot is short and the shell extends a considerable distance beyond its posterior end. The parapodial flaps, which are part of the foot, therefore only fold around the anterior end of the shell. The posterior flap of tissue which looks like part of the foot, is in fact an outgrowth from the mantle cavity. A similar "false posterior foot" is found in species of Haminoea.
Reference:
•Helbling, G.S. (1779). Bulla cylindrica. In: Abhandlungen einer Privatgesellschaft in Böhmen zur Aufnahme der Mathematik, der väterlandischen Geschichte, und der Naturgeschichte, zum Druck befördert von Ignaz Edlen von Born. Prag, Vol 4, p. 122, Pl. ii, f.30,31.
Rudman, W.B., 1998 (December 18) Atys cylindrica (Helbling, 1779). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/atyscyli
Related messages
Re: Cephalaspidean from the Philippines
May 24, 2002
From: Clay & Patty Jo
Bill,
This looks like A. cylindrica. I have the same color form from 20 m off of Mindoro. A. semistriata would have a relatively shorter/thinner/more inflated shell.
Clay & Patty Jo
ccarlson@kuentos.guam.net
Carlson, C. & Hoff, P.J., 2002 (May 24) Re: Cephalaspidean from the Philippines. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7045Thanks Clay & Patty Jo,
Bill Rudman
Cephalaspidean from the Philippines
May 22, 2002
From: Erwin Köhler
Dear Bill,
Here is the next one from the Philippines,
Negros Oriental Island, Lipayo, divesite
"Dauin", nightdive.
Size: 17mm
Depth: 14m
05.March 2002
Erwin
Erwin@medslugs.de
Köhler, E., 2002 (May 22) Cephalaspidean from the Philippines. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6628Dear Erwin,
This is probably Atys cylindrica, but the pinkish blotches, visible through the shell, suggest that it may be Atys semistriata. Clay Carlson is more familiar with the variability of live animals than I am, so hopefully he can give us some input.
Best wishes,
Bill Rudman
Atys from New Caledonia
June 17, 2001
From: Claude Berthault
Dear Bill,
Many thanks for your answer and your ID.
Votre site est fantastique!"
I send 2 photos of Atys sp? (Anse Vata, Noumea, 2 m. New Caledonia).
Best wishes
Claude
berthault@noumea.ird.nc
Dear Claude,
I am pretty sure that this Atys cylindrica though it is sometimes difficult to be sure withour an empty shell to look at. The animal is a lot more darkly mottled that in my photo at the top of the page from Koumac, but many species of these herbivorous bubble shells are quite variable in the colour of their animals ranging from a very dull light grey mottling to the dark brown in these photos.
Best wishes,
Bill Rudman
