Relevant Synonyms Saccostrea glomerata (Gould, 1850) Ostrea commercialis Misidentification ? Saccostrea cucullata  photo: L. Mizzan

SHORT DESCRIPTION As in Saccostrea cucullata, Saccostrea is considered to be the common oyster of Indo-Pacific shores. A chaotic taxonomy of the genus has, however, resulted from morphological plasticity among ecotypes. Some Saccostrea "forms" have been cross-referred to by different names by different authors. For example S. commercialis has been regarded as subspecies of S. cucullata due to similar chell characteristics. Torigoe (1981) updated the controversy related to Saccostrea taxonomy and concluded that S. commercialis is a synonym of S. glomerata, different from S. cucullata. However, the differences are apparent only at the molecular level. color : blue black to grey-white and blue-black or purple margins. Internally chalky white with purple areas and black-purple or brown margins. common size : in Australia length to 100 mm (cultivated specimens up to 255 mm). DISTINGUISHING CHARACTERISTICS Based on molecular biology studies of S. commercialis in eastern Australia and S. cucullata in western Australia and Hong Kong, these can be regarded as different species in terms of DNA 16S sequences (Lam and Morton, 2001). BIOLOGY / ECOLOGY Epifaunal, suspension feeder, lives cemented to rocks/hard substrata. habitat : attached to rocks in subtidal areas.

1st Mediterranean record Venice Lagoon, Adriatic, 1985 [1984]. DISTRIBUTION Worldwide: original distribution in eastern Australia (Victoria, New South Wales to Queensland) and New Zealand. Its distribution in the Indo-west Pacific and overlap of S. cucullata has to be defined (Lam and Norton, 2001). Mediterranean: imported in 1984 in the Venice lagoon, Adriatic (Cesari and Pelizzato, 1985b) from where it expanded northwards (St Erasmo Island). ESTABLISHMENT SUCCESS In the northern Adriatic lagoons, no specimens have been recorded since 1990 (Mizzan, 1999). speculated reasons for success : - MODE OF INTRODUCTION Imported in the Adriatic for cultivation. IMPORTANCE TO HUMANS Edible, its cultivation is very popular in Australia and New Zealand.

KEY REFERENCES Cesari P. and Pellizzato M., 1985b. Molluschi pervenuti in Laguna di Venezia per apporti volontari o casuali. Acclimazione di Saccostrea commercialis (Iredale and Roughley, 1933) e di Tapes philippinarum (Adams and Reeve, 1850). Bollettino Malacologico, 21(10-12): 237-274. Mizzan L., (1998) 1999. Le species alloctone del macrozoobenthos della Laguna di Venezia: il punto della situazione. Bollettino del Museo Civico di Storia Naturale di Venezia, 49: 145-177. Torigoe K., 1981. Oysters in Japan. Journal of Science, Hiroshima University, Series B, Division 1, 29: 291-481.   FEEDBACK / COMMENTS TO AUTHORS

Last update : December 2003 ©ciesm 2002