SEX DIFFERENTIATION AND GROWTH PERFORMANCE TRIALS OF TWO GENOTYPES OF TILAPIA ADMINISTERED WITH ANDROGENIC HORMONE
Abstract: The aim of this
study was to know the effect of dietary administration of androgenic hormone
methyltestosterone on two sex genotypes of Nile tilapia i.e. XX and XY
genotype, especially to sex ratio, growth rate, survival rate, food conversion
ratio and harvest yield. XX genotype was obtained from XX male matted with XX
normal female, and XY genotype was obtained from YY super-male matted with XX
normal female. Methyltestosterone was administered seven days after larvae
hatching for 28 days. After that, the fish were reared in hapas for 60 days and
then placed in growout ponds for 120 days period. As check population, mixed
sex genotype was used consisting of 50% XX genotype and 50% XY genotype. The
result showed that dietary administration of methyltestosterone in XX genotype
significantly increased male proportion about 82.42%, compared with control XX
population (7.55%). The same treatment in genotype XY did not significantly
increase the proportion of male (85.13%), compared with control XY population
(79.81%). In grow-out ponds, all male population (XY genotype and sex reversed
from XX genotype) have better growth rate than all female and mixed sex
populations. Dietary administration of methyltestosterone in both of XX and XY
genotypes increased growth rate of these populations resulting in the increased
of total biomass at harvest time.
Keywords: nile tilapia;
androgenic hormone; sex ratio; growth rate and yield harvest
Author: Didik Ariyanto, Komar
Sumantadinata, Agus Oman Sudrajat
Journal Code: jpperikanangg100020
