Effect of different level of 17 alpha-Methyl Testosterone on Parturition, sex reversal and growth performance of Guppy (Poecilia reticulata peters, 1859).

Abstract

The ‘guppy’ Poecilia reticulata is considered to be the most popular aquarium fish of the family Poeciliidae. Inthe present study parturition, sex reversal and growth performance of ‘guppy’ carried out by incorporating different level (50,100, 150, 200 and 250 mg) of 17ααααα-Methyl Testosterone (MT) with starter feed mixed with ethanol. Methyl Testosterone wasadministered orally with starter feed mixed with ethanol alcohol only to the gravid female, the respective offspring given onlynormal starter feed. Sex ratio was determined by observing the secondary sexual characters and microscopic examination of thegonads. Results of the experiment showed that, parturition of ‘guppy’ occurred after 15 days when feed was treated with MT at150 mg kg-1 compare to other treatments. The maximum male percentage of 76.67% was observed in 250 mg MT kg-1 whileminimum of 56.67% was found in 50 mg MT kg-1 treated tanks, control it was 53%. So in this study the effect of hormone onthe gravid female was found to be positive towards the masculinization of fries. The mean length and weight of “guppy” wasfound increasing with respect to hormonal treatment. Highest survival rate was observed in the control group (83.67±1.35%)and lowest (43.12±0.89%) in 250 mg hormonal treated group.