Flabellina ischitana
Hirano & Thompson, 1990

Order: NUDIBRANCHIA
Suborder: AEOLIDINA
Family: Flabellinidae

DISTRIBUTION

Mediterranean

PHOTO

UPPER: Lighthouse Reef, Qawra, Malta, 25m, May 1996. PHOTO: Erwin Koehler.
LOWER: Bay of Algeciras (Strait of Gibraltar, southern Spain) at 5m depth on Eudendrium racemosum,May, 1997. PHOTO: Cesar Megina.

'The general body color, including the rhinophores, oral tentacles, and ceratal bases is violet, though the apical region of oral tentacles and rhinophores is opaque white. The branches of the digestive gland can be seen through the skin of the ceras. Their color is orange to orange-red. The subapical zone of the cerata has an opaque white ring that partially obscures the cnidosacs, while the apex is hyaline white'... Cervera, Lopez-Gonzalez & Garcia-Gomez, 1998.

A very similarly coloured species, Flabellina affinis, has long been confused with Flabellina ischitana. The differences between the two were enumerated by Hirano & Thompson (1990) and more recently Cervera, Lopez-Gonzalez & Garcia-Gomez (1998). Essentially in Flabellina ischitana the ceratal surface is translucent, without violet colouration, while in Flabellina affinis the zone under the subapical white ring is opaque violet, obscuring the digestive gland.

See Erwin's message, and further photos at Erwin Koehler's list of opisthobranchs on the Web at http://www.medslugs.de/Opi/Opisthobranchia.htm

See Lucas Cervera's message below suggesting that Erwin Koehler's photo above is possibly an unnamed species, rather than F. ischitana.

Reference:
• Hirano, Y.J. & Thompson, T.E. (1990). Flabellinid nudibranchs from the Bay of Naples, with a description of a new species, Flabellina ischitana. Journal of Molluscan Studies, 56: 345-354

Authorship details
Rudman, W.B., 1999 (June 19) Flabellina ischitana Hirano & Thompson, 1990. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/flabisch

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