Genetic parameters of a snakeskin gourami (Trichopodus pectoralis, Regan 1910) base population created from crossing three hatchery stocks

Abstract

A base population with a broad genetic background is a prerequisite for a successful selection program. In the present study, a synthetic base population of snakeskin gourami (Trichopodus pectoralis) was established by crossing three farmed stocks following a nested mating scheme. At 120 days after hatching (DAH), after being separately reared in hapas, all 79 full-sib families (16 half-sibs) obtained were tagged using elastomer tags and communally reared in cages until 270 DAH. Heritability, estimated using an animal model, was low for all traits at 120 DAH (0.0002–0.0514 for growth traits and 0.01 for the condition factor, K). At harvest age (270 DAH), heritability was moderate for growth traits (0.3016–0.3644) but low for K (0.2119). All heritability estimates were associated with low SE, while common environmental effect (c2) was also low. Most of the genetic correlations (rg) among traits were extremely low at 120 DAH, while at 270 DAH, rg approached 1 among growth traits and was moderate between K and growth traits. Thus, due to sufficient additive genetic variation of growth traits in this synthetic population with minimal effects from genetic variation other than additive, sufficient selection response is expected.