Induksi buatan pada perkembangan gonad ikan tor soro

Abstract

Tor soro is an endemic species of fresh water fish in North Sumatera, that has an important economical value. Nowadays the population of Tor soro tends to decrease. Currently, the fish has been successfully domesticated and in the future, it is expected to be the candidate for aquaculture. However, it is still a problem exist due to the frequency of gonad maturation in a year. Therefore, study on induction of gonadal development by Pregnant Mare Serum Gonadotropin (PMSG) and estradiol-17β was conducted. This research was aimed to obtain mature fish outside the spawning season with hormonal injections. The blood analysis was conducted to evaluate the relationship between reproduction status and blood chemistry. The first research was carried out descriptively to understand changes in gonad maturity and blood chemistry profile of fish blood plasm in the pond. The results indicated that a spawning season in June and September was characterized by the maximum size of the oocyte (3.0 ± 0.03 mm). The second research was carried out by using Factorial Completely Randomized Design for 12 dosages of PMSG and estradiol-17β. Sampling of oocytes and blood plasm was performed every month during a year (January to December 2011) to analyze the development of the gonads and the concentration of estradiol-17β. The results showed the ability of PMSG and estradiol-17β in accelerating the development of the gonads with the presence of oocytes in the two months after injection, and accelerating spawning. The best treatment dosage was 4 IU PMSG. This result was indicated by the low concentration of estradiol- 17β at spawning. The reproduction profile of Tor soro was also indicated by the changes of blood plasm chemistry analysis including the total protein, glucose, cholesterol, and triglyceride concentrations. The concentrations with low total protein, cholesterol, triglyceride but high glucose may be indication of the spawning activity of the fish. Finally, the use of PMSG may effectively stimulate the gonadal development of young female fish.

Tor soro merupakan salah satu spesies ikan air tawar yang mempunyai nilai ekonomis dan budaya yang tinggi. Populasi ikan Tor soro di alam tergolong langka . Dewasa ini upaya untuk membudidayakan ikan Tor soro masih berlangsung, karena ikan ini merupakan jenis yang baru didomestikasikan dan reproduksinya belum mencapai optimal. Bertolak dari hal tersebut maka penelitian ini dilakukan sebagai upaya pengembangan teknologi manipulasi hormonal untuk mempercepat perkembangan gonad induk agar dapat meningkatkan potensi ikan Tor soro sebagai kandidat ikan budi daya. Penelitian ini bertujuan untuk mengkaji perkembangan gonad ikan Tor soro yang diinduk si dengan penyuntikan Pregnan t Mare Serum Gon adotropin (PMSG) dan estradiol - 17β serta menganalisis perubahan kimia darah terkait dengan status reproduksi.