Ventomnestia villica
(Gould, 1859)
Order: CEPHALASPIDEA
Superfamily: HAMINOEOIDEA
Family: Haminoeidae
PHOTO
Guam, Toguon Bay, 8m; 27 May 1993 (C.27) [the average size of the animals we have measured is a little over 4mm -- the largest 5.5mm. we don't look for largest and mallest so there are probably larger forms around.] PHOTO: C. Carlson & P.J.Hoff.
Here is a photo of some examples from a breeding population which gives some idea of the variation that may occur. A common form not shown has a single red line. Ventomnestia villica may be the same as V. bizona (A. Adams, 1850).
Ventomnestia has a fairly heavy shell, gizzard plates with 6 to 7 heavy ridges covered with rods. The radula formula for V. villica is 2.1.2.
One characteristic of the haminoeids is the absorption of all but the outer 1 1/2 whorls of the shell. This is also true of V. villica, except that the periostracum has been retained so that the liver remains coiled.
Earlier studies based upon shell alone had Ventomnestia as a cylichnid or retusid form. It is a good example of the need for wet material (e.g. living/preserved from living specimens) in the study of the bubble shells.
C. Carlson & P.J.Hoff.
Reference:
• Gould, A.A. (1859). Descriptions of shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist., 7: 40-166
Carlson, C. & Hoff, P.J., 2000 (February 3) Ventomnestia villica (Gould, 1859). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/ventvill
Related messages
Re: Ventomnestia
February 9, 2000
From: Erwin Koehler
Dear Bill,
Who is the author of the genus Ventomnestia?
Erwin
Medslugs.Koehler@t-online.de
Koehler, E., 2000 (Feb 9) Re: Ventomnestia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1875Dear Erwin,
It was named by Iredale for a small 6mm long shell dredged from Sydney Harbour, and thought by him to look quite like Cylichna bizona A.Adams.
To my knowledge no one has studied the anatomy of the type species, Ventomnestia colorata, so until living specimens are found, the use of the genus name Ventomnestia will be problematic.
Best wishes,
Bill Rudman.
•Iredale, T. (1936) Australian molluscan notes, 2. Records of the Australian Museum, 19(5): 267-340.
Rudman, W.B., 2000 (Feb 9). Comment on Re: Ventomnestia by Erwin Koehler. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1875re: Bubble shell from Kerama Id
February 4, 2000
From: C. Carlson & P.J.Hoff
Bill,
Mr. Ono's bubble shell is probably Ventomnestia villica (Gould, 1859).
I have attached some examples from a breeding population which gives some idea of the variation that may occur. A common form not shown has a single red line. Ventomnestia villica may be the same as V. bizona (A. Adams, 1850). The only wet material we have for V. bizona is a small juvenile from Bali and have not yet tried to make any internal comparisons.
Ventomnestia has a fairly heavy shell, gizzard plates with 6 to 7 heavy ridges covered with rods. The radula formula for villica is 2.1.2. One characteristic of the haminoeids is the absorption of all but the outer 1 1/2 whorls of the shell. This is also true of V. villica, except that the periostracum has been retained so that the liver remains coiled.
Earlier studies based upon shell alone had Ventomnestia as a cylichnid or retusid form. It is a good example of the need for wet material (e.g. living/preserved from living specimens) in the study of the
bubble shells.
PHOTO DETAILS: c.27; Guam, Toguon Bay, 8m; 27 May 1993. [the average size of the animals we have measured is a little over 4mm -- the largest 5.5mm. we don't look for largest and smallest so there are probably larger forms around.]
Clay & Patty Jo.
Guam
clay.carlson@kuentos.guam.net
Carlson, C. & Hoff, P.J., 2000 (Feb 4) re: Bubble shell from Kerama Id. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1843Dear Clay & Patty Jo,
Thanks for your help. As you say, we definitely ned to know more about the animals.
Bill Rudman.
Bubble shell from Kerama Island
February 1, 2000
From: Atsushi Ono
Dear Bill,
How did you enjoy your holiday? I enjoy my winter holiday now.
Thank you for ID of my photo Hamineobulla kawamurai.
Here is another cephalaspid species from Kerama Is, near Okinawa, Japan. It was 4m deep, on a rope covered with algae and sponge. Shell length is 4mm. This animal moved very slowly. It has small brown and milk white dots on its translucent headshield and body.
Could you help me to identify this species?
Sincerely,
Atsushi Ono
ononini@cosmos.ne.jp
Ono, A., 2000 (Feb 1) Bubble shell from Kerama Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1804Dear Atsushi,
I must warn you that my identification of your earlier photo as Haminoebulla kawamurai was only tentative. Many of these bubble-shells are only known from their shells, so photos of the live animals are difficult to recognise.
I am not sure of this photo. Perhaps Clay Carlson, who is a specialist with the bubble-shells, will be able to give us some clues. The brown spots on the shell may be a useful character.
I hope your winter holiday is not too cold,
Best wishes,
Bill Rudman.
