Tropical Indo-West Pacific.
UPPER: Two adult animals, Zanzibar, Tanzania. (Up to 70mm long alive). July, 1971.
LOWER: Juvenile animal, Kunduchi Beach, Dar es Salaam, Tanzania. 15mm long alive. May 1974
PHOTOS: Bill Rudman.
Note added 4 Feb 2006: Philinopsis cyanea is almost certainly a synonym of the earlier Philinopsis speciosa Pease, 1860. See that Fact Sheet for a fuller discussion.
Philinopsis cyanea, is quite a variable species found throughout the tropical Indo-West Pacific. It varies in colour from plain black to black with blue, white, yellow or brownish-yellow markings. Sometimes animals have a pale brown background colour. Juvenile animals are often more colourful than adults. In my picture alongside, of a juvenile animal from Dar es Salaam, Tanzania (May, 1974), you can see the characteristic shape of species of Philinopsis. The posterior edge of the headshield has a tapering crest, which stands erect, and the body is cylindrical in shape. Species of Philinopsis are usually found burrowing through sand or mud. They have lost their radular teeth.
There are two quite distinct groups in the genus, one with a large eversible buccal bulb like Philinopsis cyanea, and a second with a long tubular pharynx like Philinopsis gardineri. The group with the large buccal bulb feed on other bubble shells, such as Bulla, Atys and Haminoea.
They feed by partially everting their large muscular buccal bulb, (or pharynx), to envelop their prey which they swallow whole. After digestion, the empty, unbroken shell of the prey is regurgitated, being too large to pass through the gut. Species of Philinopsis, when collected, often spit out two or three clean, unbroken bubble shells.
I remember once in Zanzibar collecting some animals from sea grass beds where the bubble shell Bulla ampulla was also abundant. The Philinopsis ranged in length from 30-70mm and within 2 to 3 hours all had regurgitated 3 to 5 Bulla shells ranging in length from 5-15mm. They clearly have quite an impact on the ecology of their neighbourhood.
• Rudman,W.B., 1972. A comparative study of the genus Philinopsis Pease, 1860 (Aglajidae, Opisthobranchia). Pacific Science, 26: 381-399.
• Rudman,W.B., 1972. Structure and functioning of the gut in the Bullomorpha (Opisthobranchia). Journal of Natural History, 6: 547-560.
Rudman, W.B., 1998 (July 27) Philinopsis cyanea (Martens, 1879). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/philcyan
What is Philinopsis cyanea doing?
From: Valda Fraser, August 6, 2008
Dark colour form of Philinopsis cyanea
From: Hugues Flodrops, August 5, 2008
Philinopsis cyanea from Reunion Island
From: Hugues Flodrops, February 18, 2008
Philinopsis taronga? from Reunion Island
From: Hugues Flodrops, February 18, 2008
Philinopsis cyanea from Perth
From: Brent Murdoch, January 17, 2007
Philinopsis cyanea? from Taiwan
From: Ching-Yao Chan, May 17, 2006
Philinopsis cyanea? from Victoria, Australia
From: Trevor McMurrich, March 24, 2006
Re: Aggregation of Stylocheilus striatus in Indonesia 
From: Paul Whitehead, January 23, 2006
Philinopsis gardineri? from Reunion Island
From: Philibert Bidgrain, December 13, 2005
Re: Philinopsis cyanea mating in Reunion Island
From: Francis & Pirjo Pellet, November 25, 2005
Philinopsis cyanea spawning at Reunion Island
From: Philibert Bidgrain, November 25, 2005
Two big Philinopsis cyanea mating in Reunion Island
From: Philibert Bidgrain, November 23, 2005
More colour forms of Philinopsis cyanea
From: Dong Bum Koh, June 13, 2005
Philinopsis cyanea ... eating?
From: Binyamin Koretz, April 28, 2005
Philinopsis cyanea from South Korea
From: Dong Bum Koh, April 14, 2005
Philinopsis depicta? from the Red Sea
From: Binyamin Koretz, April 14, 2005
Philinopsis cyanea? from Indonesia
From: Francis & Pirjo Pellet, January 13, 2004
Philinopsis cyanea from Port Stephens
From: Leanne&David Atkinson, May 13, 2003
Philinopsis cyanea & possible egg mass
From: Leanne Atkinson, May 9, 2003
Philinopsis cyanea from Lembeh Strait
From: Mary Jane Adams , February 6, 2003
Philinopsis cyanea from Lizard Is
From: Nils Anthes, February 3, 2003
Philinopsis cyanea from Lord Howe Island
From: W.B. Rudman, January 10, 2003
Philinopsis cyanea from Lord Howe Is.
From: Ian Hutton, December 6, 2002
Philinopsis mating from Korea
From: Dong Bum, Koh, June 17, 2002
Philinopsis cyanea from Sulawesi
From: Mary Jane Adams, May 4, 2002
Philinopsis cyanea mating
From: Julie Marshall, May 4, 2001
Philinopsis cyanea from New South Wales
From: Erik Schloegl, April 3, 2001
Philinopsis from Mauritius
From: Owen Griffiths, July 27, 1998