GENETICS AND AQUACULTURE

As is the case with many other organisms¾ both plant and animal¾ the diversity of fish is presently being compromised, because of both overexploitation and habitat modification (including pollution).

Moreover, germplasm transfers¾ intentional and accidental¾ have caused strong genetic changes in numerous populations of (mainly freshwater) fishes. Such impacts can only be understood with a thorough knowledge of the genetics of fish populations, both in captivity and in open waters.

Genetics data are diverse and widely scattered throughout the literature

The study of genetics produced an extensive body of data such as karyotypes, electrophoretic data, heritability values from selection and genetic improvement studies, and molecular genetic data. These data are widely scattered throughout the literature making comparative studies very tedious. The FishBase tables were designed to bring these together in a standardized format. To support the acquisition, storage and use of knowledge on genetics, data have been divided into four areas:

  • GENETICS - presenting species-specific features such as chromosome number and morphology, sex-determining mechanism, genetic markers and cellular DNA contents;

  • ELECDAT - presenting, for a studied population, the different studies, loci, observed allele frequencies and related statistics;

  • GENEDAT - presenting heritability values and responses to selection;

  • STRAINS - presenting key information on cultured strains of tilapia and carp such as the source and size of the founder stock, distinctive trait(s), effective breeding number, etc.

Information relevant to aquaculture is provided in the following tables:

  • CULTSYS – presenting information on culture performance under various scenarios;

  • CULTSPEC – a sub-table of the one above, to accommodate species-specific information in multi-species systems;

  • DISREF – providing information on common fish diseases; and

  • DISEASES – recording cases of disease outbreak.

The following sections provide details on each of these tables.

Christine Casal and Liza Agustin