Inbreeding

In fish farming, if proper care is not taken the fishes can breed with their close relatives or same parental generation which may cause early mortality of fish, poor growth rates and other genetical abnormalities. This phenomenon is called inbreeding or homozygosis and the offspring is called homozygote. Homozygosis is the condition when two genes at particular locus are with same allele. Inbreeding causes the reduction of desirable traits and some times may cause fertility. If a farm based on limited number of population of brood stocks the progeny over long periods can face inbreeding problems.

The advantage of inbreeding:

Sometime the inbreeding is not encouraged and has some advantageous point also. Production of inbreed lines are very use full in improvement of stock. Production of inbreed lines have following advantages.

· To produce pure lines of fish
· Pure lines of strains are used for perfect hybridization of fish to obtain favourable heterosis, monosex.
· Pure lines help in gene mapping
· To determine

1. Phenotypical variations
2. Extent of inbreeding depression
3. chromosomal makeup to the fish