Application of 17α-methyltestosterone to enhance broodstock maturation of the domesticated black tiger shrimp (Penaeus monodon): A comparative study of injection method and oral method

The effects of 17α-methyltestosterone administration on spermatophore quality in captive broodstock of tiger shrimp Penaeus monodon were investigated using injection method and oral method based on the optimized protocol. The experiment was designed to compare the oral administration group and injection group with two replications during a 38-day experimental period. Captive male broodstock of tiger shrimp weighing 57-95 g was collected from ponds and stored in a 10,000 m3 concrete tank (20 shrimp/tank). Male broodstocks were injected and orally administrated with 17α-methyltestosterone at the dose of 300 ng/100 g body weight. Data indicates that the injection of 17α-methyltestosterone showed the percentage of mature broodstock count and the percentage of normal spermatozoa count 1.07 and 1.38% higher and significantly differs from oral administration through mixing in feed at the maturation stage. However, at the time of the maturation and 1st re-maturation of both the methods, the weight of the spermatophores and the number of spermatozoa did not show any difference. Based on the comparison of the two methods used, the results are obtained that the administration of the hormone 17α-methyltestosterone can be done both through mixing in feed and through injection, but the administration of hormones through injection gives better results than the broodstock matures first simultaneously.