Relevant Synonyms Polycera grupa Marcus and Marcus, 1967 Misidentification -  drawing: Tuvia Kurz

SHORT DESCRIPTION Body medium sized, elongated, wider just before the branchial plume, which is located in the middle of the notum. Scattered tubercles of different sizes are found throughout the body surface. The frontal veil of the head bears four to six elongate processes, two or three on each side. There is also a group of extrabranchial finger-like appendages to the side of the gills (three per side). Branchial plume composed of 9-12 tripinnate gills. Rhinophores perfoliate, without sheaths, and oral tentacles short and simple. color : general body color translucent whitish-grey densely peppered with black greyish dots, giving the animal an overall grey-black appearance. Papillae translucent white with a yellow-gold ring towards the centre. Tip of the tail also gold. White pigmentation forms irregular white lines on the edges of the notum and along the mid dorsal line of the foot. common size : 10-20 mm, max. 40 mm. DISTINGUISHING CHARACTERISTICS It is readily distinguishable from the others Mediterranean species of Polycera. P. quadrilineata and P. elegans show a conspicuous and bright pattern of orange pigmentation. P. dubia has a cryptic coloration, as in P. hedgpethi, but its velar appendages and extrabranchial processes are clearly shorter. BIOLOGY / ECOLOGY Temperate-tropical species that is frequent in fouling communities on ship hulls. habitat : on the branching bryozoans Bugula neritina 0-1 m deep in lagoonal environments, together with typical fouling organisms, such as the ascidian Ciona intestinalis.

1st Mediterranean record Italy, 1991 [1986]. DISTRIBUTION Worldwide: common in Northeast Pacific, from California (where it was originally described) to Baja California; introduced by shipping in South Africa, Angola, eastern Australia, and New Zealand. Mediterranean: only known from Fusaro lagoon, Naples, Italy in 1986 (Cervera et al., 1991). ESTABLISHMENT SUCCESS A single record (seven specimens) in Italy. speculated reasons for success : - MODE OF INTRODUCTION Probably introduced by shipping. IMPORTANCE TO HUMANS None.

KEY REFERENCES Cervera J.L., Garcia-Gomez J.C., Toscano F. and García F.J., 1991. Polycera hedgpethi Marcus, 1964 (Gastropoda, Nudibranchia), una especie indopacifica descubierta en el Mediterraneo. Iberus, 8(2): 225-231. Gosliner T.M., 1982. A new record of the nudibranch gastropod Polycera hedgpethi Marcus, from the Indian Ocean of South Africa. Journal of Molluscan Studies, 48: 30-35. McDonald G.R., 1980. Guide to the nudibranchs of California. American Malacologists, inc., Melbourne, Florida, 72 p.   Miller M.C., 2001. Descriptions of the dorid nudibranchs Polycera hedgpethi Marcus, 1964 and P. fujitai Baba, 1937 in New Zealand (Gastropoda: Opisthobranchia). Journal of Molluscan Studies, 67: 489-497. FEEDBACK / COMMENTS TO AUTHORS

Last update : December 2003 ©ciesm 2002