REPRODUCTIVE ASPECTS OF CULTURED HUMPBACK GROUPER (Cromileptes altivelis) FOR SUPPORTING SEED PRODUCTION

Abstract

Humpback grouper (Cromileptes altivelis) has been successfully spawned in 2000 by IMRAD (Institute of Mariculture Research and Development) and there are already the third generation (F3) currently. The reproductive aspects need to be studied to support the success of seed production. Humpback grouper reared in floating cage (F1 and F3) had matured (gonad stage 4) while F2 fish reared in concrete tanks has spawned. Gonadal maturity stage of 38 fishes from first generation (F1) and 35 fishes from the third generation were observed in June 2013 and compared to gonadal maturity stage of 18 fishes from the second generation observed in June 2009. Samples were measured in total length and body weight and gonads were taken for histology preparation to determine gonadal maturity stage and the sex. From the histological observation of the gonads, it showed that all female humpback grouper were in early maturity stage (stage I and II) with gonadal maturity index between 0.12% and 5.45%. Further, it was observed that the same gonad was found in different maturity stage and concluded that humpback groupers were multiple spawners (asynchronous). By determining gonadal maturity level, it was also known the minimum size for grouper ready to spawn.

Evaluation of humpback grouper, Cromileptes altivelis reproduction because of mating between males from the wild and females from cultivation

“…Therefore, the success of spawning, which begins with the perfect maturity of the gonads, depends on several factors, including sex change (sex reversal), the feed given, the environment, and others [8]. Feed is a very important factor in grouper cultivation [19].…”

“…One of the causes of the difficulty in obtaining broodstock from cultivation is the time it takes to reach sexual maturity. In sustainable fish farming, dependence on broodstock from nature must be reduced gradually and replaced with domesticated hatchery broodstock followed by a selective breeding program [8].…”

Reproductive Biology Pleco (Pterygoplichthys pardalis Castelnau 1855) in Ciliwung River

“…Hal tersebut dikarenakan bobot gonad akan meningkat seiring dengan pengendapan kuning telur (Solang, 2010). Selain itu, semakin tinggi TKG pada ikan betina akan meningkatkan IKG (Sembiring et al, 2014). Pengendapan kuning telur terjadi secara bertahap dalam perkembangan tingkat kematangan gonad.…”

“…Pertumbuhan ikan yang bersifat allometrik negatif dapat ditandai dengan tubuh ikan yang ramping. Kondisi ini diperkuat dengan penjelasan yang menyatakan bahwa ikan memiliki kemampuan bertambah panjang lebih cepat daripada bertambah berat tubuh (Sembiring et al, 2014).…”