Philinopsis gardineri
(Eliot, 1903)

Order: CEPHALASPIDEA
Family: Aglajidae

DISTRIBUTION

Known previously, only from the tropical western Pacific, but records on the Forum from Reunion Island and Western Australia show it has a wide Indo-West Pacific distribution.

PHOTO

Heron Island, Great Barrier Reef, Queensland, Australia. June 1983. Up to 5cm long alive. Photo: Bill Rudman.

Philinopsis gardineri is very similar in colour to the related Chelidonura varians from which it can be easily separated by the long pointed posterior tails present in Chelidonura.

The Aglajidae are all carnivorous hunters, and species of Philinopsis are usually found burrowing in sand or sandy mud. There are two groups of species at present placed in the genus Philinopsis. The "typical" group, represented by Philinopsis cyanea , have a large partially eversible buccal bulb which is used to catch the bubble shells and other opisthobranchs which are their prey. Philinopsis gardineri represents the second "atypical" group which have a long muscular, tubular buccal bulb. We have no information on how this second group feed but it is possible that they use the buccal bulb as a long eversible tube which can catch prey (worms?) in narrow burrows or crevices. Bergh informally suggested the name "Boridium" for the group with the tubular buccal bulb, but as he wasn't sure whether his anatomy was correct or not he never formally introduced the name. Species with this foregut are usually quite easy to identify in the living animal as the folds of the tube form a rounded central crest on the head which can be seen on the photo alongside. It reminds me of the front of a jumbo jet. Other species with this type of buccal bulb include Philinopsis pilsbryi and Philinopsis lineolata.

References:
• 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.

Authorship details
Rudman, W.B., 1998 (October 14) Philinopsis gardineri (Eliot, 1903). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/philgard

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