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Three kind of genetic improvements can be expected for fish by controlling the sex expression, by inducing sterility and by selective breeding. In this paper, the state of the art of the research advances in these domains is made for the three main marine fish reared in Europe: the sea bass, the sea bream and the turbot:

-         Sex control methods are almost available for sea bass and partial data usable for sea bream but nothing is published yet for turbot although a European project is ended on the subject. For the 3 species, the female is the most interesting sex as growing 10 to 40% bigger.

-         Sterility can be obtained by meiotic triploidy in bream and bass. In both species, males still develop testis even though not functional. Direct triploidy depresses fish growth performances (15-20%) but in bass, 3n females perform the same growth than 2n males. For none of the 3 species, triploids issued from the tetraploids were yet obtained

-         Selective breeding programs are held for almost 10 years (2-3 generations) for the 3 species in the main European countries producing these marine fish but very few genetics parameters or data are known. A few heritability data are available for growth in bream and a large European project is ending in 2004 that will bring genetic parameters for essential traits of commercial interest for 253 sea bass families reared in 4 environments.

Béatrice Chatain works at IFREMER, the French Research Institute for Exploitation of the Sea since 1982 at the laboratory of Palavas-les-Flots (south France): she was head of the “Experimental Marine Zootechny” team from 1982 to 1991 and has been  head of the “Fish Genetic” team since. She is twice Doctor in Oceanology, speciality aquaculture: a first PhD graduated in Japan.on Japenese seabream and afterwards a Doctorat ès Sciences obtained at the Marseille Univ. on European seabass and seabream.Specialities:Larval zootechny of various marine fish. Sex determinism and ploidy manipulations in seabass.

Contact details:  bchatain@ifremer.fr