Pengaruh Lama Waktu Pery.Ndaman Induk Di Dalam Larutan Hormon 17-Metiltestosteron Terhadap Nisbah Kelamin Anak Ikan Gapi, Poecilia Reticulata Peters

Abstract

This experiment was carried out to study the effect of female broodstocks immersion in 17amethyltestosterone (MT) solution on sex ratio of their offspring, Three-months old males and females were paired to mate in aquaria for four days. Broodstocks were fed with frozen blood worm and water flea 2-3 tii-nes daily. Twelve days after mating, female broodstock were treated by immersing in 2 mg/1 MT solution for 0. 6, 12, 24 and 48 hours. Birthed guppy babies were collected and reared separately from their parents. During the rearing period, the babies were fed with artemia nauplius and silkworm until identification for male and female. Percentage of female offspring in control group were higher than those of male. Exposure of pregnant females to MT solution for 0, 6, 12, 24, and 48 hours resulted in 42, 1'/o, 51%, 84,6%, 1 00%, dan 100% of males offspring, respectively. The best result was obtained from 24 hours treatment. Longer treatment duration tend to shorten time interval between treatment and birth.