Influence of chronic administration of LHRH-analogue and/or 17 α-methyltestosterone on maturation in milkfish, Chanos chanos

• Published in: Aquaculture Vol. 59; no. 2; pp. 147 - 159
• Main Authors: Lee, C.-S., Tamaru, C.S., Banno, J.E., Kelley, C.D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.1986; Elsevier Science
• Subjects: Animal, plant and microbial ecology; Applied ecology; Aquaculture; Biological and medical sciences; Chanos chanos; Freshwater; Fundamental and applied biological sciences. Psychology; Hormone; Methyltestosterone; Androgen; Gonadotropin RH; Hawaii; Oceania; Hypothalamic hormone; Ripening; Freshwater environment; Vertebrata; Treatment; Polynesia; Analog; Pisces; Pisciculture; Hormonal regulation; Sex steroid hormone
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/0044-8486(86)90127-4

Five chronic hormone therapies; cholesterol pellets containing 200 μg of LHRH-a (LHRH-a pellet); silastic tubing packed with either 250μg of dissolved 17α-methyltestosterone (liquid 17α-MT capsule) or 10 mg crystalline 17α-methyltestosterone (crystalline 17α-MT capsule); or the combinations of LHRH-a pellets plus a liquid 17α-MT capsule or LHRH-a pellets plus a crystalline 17α-MT capsule, were tested to determine the best treatment for inducing maturation in captive milkfish ( Chanos chanos). Experimental groups of 20 milkfish each received one of these five therapies. A sixth control group received placebo implants. LHRH-a pellets were administered monthly; crystalline 17α-MT capsules were administered once, and liquid 17α-MT capsules were administered twice, at the beginning of the experiment and 3 months later. Results show that the combination of LHRH-a pellets plus liquid 17α-MT capsules in the most effective hormone therapy for enhancing the maturation of both sexes. Fifty percent of these fish matured in April, 1 month after implantation, and close to 90% of the fish in this treatment matured by July. The combination of LHRH-a pellets plus crystalline 17α-MT capsules enhanced the maturation of male milkfish but not female. LHRH-a alone was also effective in the maturation of females, but was the least effective of all treatments in maturing males. 17α-MT capsules alone, in either form, did not induce maturation in female milkfish.