Relevant Synonyms ? Melibe rangi Bergh, 1875 ? Melibe bucephala Bergh, 1902 Misidentification -  photo: A. Zuljevic

SHORT DESCRIPTION Body large, resembling a mass of vegetal debris, with large cerata and a greatly dilated and rounded oral hood around its mouth, fringed with retentive tentacles. Rhinophores very small and lamellate, emerging from tall sheaths, into which they can be retracted. Large cerata arranged along the notal edge (up to 10 pairs), easily autotomized and regenerated. Each one is oar-like shape, with a cylindrical stem and a flattened distal blade. Surface of the body and cerata bearing tubercles and ramified appendages (gills). color : somewhat translucent with a pale yellow-brown or greenish ground color. The tubercles are brown, and the branched appendages paler. common size : usually 10-20 cm. DISTINGUISHING CHARACTERISTICS This bizarre-looking nudibranch is the largest and widespread Indo-Pacific. Melibe fimbriata is clearly different from Tethys fimbria, the native representative species of the family Tethyidae in the Mediterranean which is also large, but it is whitish, with the cerata bifurcated apically with black spots. BIOLOGY / ECOLOGY Species of this genus prey upon crustaceans, which they trap with their oral hood. Most species are capable of swimming by moving their body from side to side. Many species gain additional nutrition from symbiotic zooxanthellae. The spawn formed a delicate colorless jelly-ribbon and contained spiralling strings of egg capsules. Each egg capsule contained up to 3 embryos. The swimming veligers hatched after 8 days at 21°C. The cerata of this species contain scattered defensive glands that secrete a characteristic hyaline slime, evident when handling the living animals. habitat : on Milos Island the specimens were found drifting, swimming and crawling around and among Cymodocea nodosa beds, at 10-12 m in depth, in a geothermally heated area; usually found in muddy seagrass beds or on muddy bottoms 2-3 m deep.

1st Mediterranean record Ionian Sea, Greece, 1986 [1970]. DISTRIBUTION Worldwide: Indo-Pacific; recorded from South Africa, East Africa, Australia, Philippines and Japan. Mediterranean: recorded first in 1970 in Cephalonia Island, Greece (Mooseleitner, 1986); successive records from Korinthiakos Gulf, Greece (Moosleitner, 1986); Strait of Messina (Mojetta, 1998); Calabria, south western Italy (G. Villani, identification confirmed by J. Templado) and Croatia, middle Adriatic (Despalatovic et al., 2002). ESTABLISHMENT SUCCESS This species seems common on the coasts of Greece: observations in Astakos inlet concern a breeding population (Thompson and Crampton, 1984). speculated reasons for success : - MODE OF INTRODUCTION Most likely via ships as there are no records from the Red Sea, and none from the Levantine Sea. IMPORTANCE TO HUMANS None.

KEY REFERENCES Despalatovic M., Antolic B., Grubelic I. and Zuljevic A., 2002. First record of the Indo-Pacific gastropod Melibe fimbriata in the Adriatic Sea. Journal of the Marine Biological Association of the United Kingdom, 82(5): 923-924. Koutsoubas D. and Cinelli F., 1997. Indo-Pacific origin gastropod species in the Aegean Sea. Melibe fimbriata Alder & Hancock, 1864 a new invader. Bollettino Malacologico, 32(1-4): 1-6. Mojetta A., 1998. Arriva dal Mar Rosso un nuovo nudibranco. Agua, Milano, 133: 19-20.   Moosleitner H., 1986. Note on the occurrence of Melibe sp. (?) in the Mediteranean (Opisthobranchia: Fimbriidae). La Conchiglia, 18(202-203): 20. Thompson T.E. and Crampton D.M., 1984. Biology of Melibe fimbriata, a conspicuous opistobranch mollusc of the Indian Ocean, which has now invaded the Mediterranean Sea. Journal of Molluscan Studies, 50: 113-121. FEEDBACK / COMMENTS TO AUTHORS

Last update : January 2005 ©ciesm 2002