Hydatina physis
(Linnaeus, 1758)
Order: CEPHALASPIDEA
Superfamily: ACTEONOIDEA
Family: Hydatinidae
DISTRIBUTION
Found circum-globally in tropical waters both in the Indo-West Pacific and the Atlantic.
PHOTO
UPPER: Shelly Beach, Manly, Sydney, New South Wales. October 1984. Shell length 45mm. PHOTO: Bill Rudman.
LOWER: Egg mass. Long Reef, Sydney, New South Wales. (Photographer unknown).
RELATED TOPIC
The Hydatinidae are the most modified of a group of cephalaspids which show the gradual diminution in the importance of the shell as a protective organ. The least modified are the acteonids (Pupa, Acteon) with a heavily calcified shell and a small, usually uncoloured animal. In Hydatina and Micromelo the shell has become thin and the animal large and brightly coloured. The protective operculum has disappeared. Species of Hydatina are very specialised worm feeders, eating only cirratulinid polychaete worms.
Reference:
• Rudman, W.B., 1972. The anatomy of the opisthobranch genus Hydatina and the functioning of the mantle cavity and alimentary canal. Zoological Journal of the Linnean Society, 51: 121-139.
Rudman, W.B., 1998 (December 18) Hydatina physis (Linnaeus, 1758). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/hydaphys
Related messages
-
Re: Food for the bubble shell Hydatina physis?
From: Lindsay Lyles, December 16, 2009 -
Hydatina physis from sthn Queensland
From: Gary Cobb, January 21, 2009 -
Hydatina physis from Florida
From: Linda Ianniello, July 7, 2008 -
Amazing proboscis on Hydatina physis from Sth Africa
From: Valda Fraser, April 8, 2008 -
Hydatina physis from Gold Coast, Queensland
From: Ian Banks, May 20, 2006 -
Hydatina physis mating
From: Marina Poddubetskaia, July 2, 2005 -
Hydatina physis laying eggs
From: Marina Poddubetskaia, July 2, 2005 -
Mysterious pink nudibranch from New South Wales
From: Eliza Middleton, January 27, 2005 -
Hydatina physis laying eggs
From: Ian Hutton, January 28, 2004 -
Hydatina physis from Japan
From: Yukari Sato, December 20, 2003 -
Re: A rose of a different color
From: Paul Whitehead, October 6, 2003 -
Hydatina physis from Japan
From: Kayoko Eto, June 11, 2003 -
Pair of Hydatina physis
From: Leanne & David Atkinson, June 7, 2003 -
Hydatina physis from Senegal
From: Marina & Patrice , April 19, 2003 -
Hydatina physis from Lord Howe Island
From: W.B. Rudman, January 24, 2003 -
Hydatina physis - more photos
From: George Evatt, June 2, 2001 -
Hydatina physis in Sydney
From: George Evatt, June 1, 2001 -
A rose of a different color
From: Mary Jane Adams, June 6, 2000 -
Hydatina, again
From: Peter Wirtz, February 15, 2000 -
Hydatina stromfelti v Hydatina physis
From: Marco Neiber, February 2, 2000 -
Food for the bubble shell Hydatina physis?
From: Ian Smith, December 19, 1999 -
What is the 'Rose Petal Bubble Shell'?
From: Lauren Peck, August 23, 1999