Edenttellina typica
Gatliff & Gabriel, 1911
Order: SACOGLOSSA
Superfamily: OXYNOOIDEA
Family: Juliidae
DISTRIBUTION
Southeastern Australia including eastern South Australia, northern Tasmania and Victoria.
PHOTO
On Caulerpa brownii. West Head, Flinders, Westernport Bay, Victoria, Australia, March 1986, AM C149520. Shells range in length form 2-5mm. PHOTOS: Bill Rudman.
" Shell small, up to 5 mm in length, broad, elongate-oval with relatively straight ventral margin and greatly curved dorsal margin, protoconch depressed, colour yellowish. Body light green with three or four dark brown or green broken horizontal lines in the shell mantles; neck and rhinophores stout. This seasonally (January-April) abundant species ranges from south-eastern South Australia and northern Tasmania to central Victoria from lower intertidal rock pools to 2 m deep. It is restricted to its algal food Caulerpa brownii, common along the open coastline." ... description from Burn 1989: p 749.
When observed on its algal food (see photo) the remarkable resemblance its mantle colour has to its food is very obvious. When it is nestled into the alga it is almosy invisible. Many of these bivalved sacoglossans are a uniform green colour and live on species of Caulerpa, such as C. racemosa, which have relatively large fluid filled 'bladders.' In these species, the shape and size of the shell matches the diameter of the bladders very well enabling them to disguise their presence very well with out colour enhancements. It is interesting that another species from southeastern Australia Midorigai australis has an elaborate colour pattern which helps it to mimic the the very small bladders of Caulerpa simpliciuscula on which it feeds.
References:
• Burn, R.F. (1960) A bivalve gastropod. Nature, 186 (4719): 179.
• Burn, R.F. (1960) Australian bivalve gastropods. Nature, 187 (4731): 44-46.
• Burn, R.F. (1965) Rediscovery and taxonomy of Edenttellina typica Gatliff and Gabriel. Nature, 206 (4985): 735-736.
• Burn, R. (1989) Chapter 12 Opisthobranchs (Subclass Opisthobranchia). In: Shepherd, S.A. & Thomas, I.M. (Editors) Marine Invertebrates of Southern Australia Part 2, South Australian Government Printer, Adelaide.
• Gatliff, J.H. & Gabriel, C.J. (1911) On some new species of Victorian marine mollusca. Proceedings of the Royal Society of Victoria, 24: 189-192.
• Hedley, .C (1912) Descriptions of some new or noteworthy shells in the Australian Museum. Records of the Australian Museum, 8(3): 131-160 + pls.
• Hedley, C. (1920) Concerning Edentellina. Proceedings of the Malacological Society of London, 14(2-3): 74-76.
• Verco, J.C. (1916) Note on Edenttellina typica, Gatliff and Gabriel. Transactions of the Royal Society of South Australia, 40: 596-597.
Rudman, W.B., 2001 (October 16) Edenttellina typica Gatliff & Gabriel, 1911. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/edentypi
Related messages
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Edenttellina typica from south-eastern Australia
From: Bill Rudman, October 20, 2001
