Jojo Subagja

Fisheries and Aquatic Sciences

Giant gourami (Osphronemus goramy) is one of the main freshwater fish of economic importance in Indonesia. Although this species has been reared for decades, particularly in the province of West Java, and naturally spawns in captivity, the availability of fry is still a limiting factor in aquaculture. Research efforts on giant gourami aquaculture are, however, limited and do not always address the difficulties encountered by fish farmers. The objectives of the present study were to provide the first description of giant gourami egg and fry production and highlight the main problems faced by farmers through targeted questionnaires and interviews. Our results show that the production of this species from eggs to juveniles is highly segmented, and there are currently no clear and standardized production methods. Farming practices vary greatly from one fish farmer to another. Climate factors (such as rain and temperature), proximity to urban areas, and the availability and quality of food are identified as the main limiting factors for egg and fry production. Based on a strengths, weaknesses, opportunities, threats analysis, we explore possible approaches to improve giant gourami aquaculture in Indonesia. The present study provides guidance for future research.

Here, on the basis of published information upon over 800 species from 39 orders and 202 families, we analyse how the size of oil globules in fish eggs varies between reproductive guilds and environments with contrasting salinities. About 80% of marine fishes produce eggs with oil globules, the volume of which (V_O) never exceeds 9% of the egg reserves and averages 2%. These proportions vary very little between marine fish species producing pelagic or demersal eggs. Fewer freshwater fishes (about 40%) produce eggs with oil globules, but their globules are much larger (mean V_O of 10%) and their volumes vary considerably between reproductive guilds: V_O is on average 3–10 times lower in freshwater species with demersal eggs than among freshwater pelagophils and aphrophils (i.e., bubble nesters), where it averages about 40% (range of 23%–69%) of the egg reserves. These results support the idea that oil globules serve to hydrostatic lift in fresh waters, but not or very little in marine waters, where egg buoyancy can be achieved at a lower energy cost through egg hydration. Advantages and constraints of oil globules in fish eggs are discussed in the light of species producing eggs with very large oil globules (V_O > 20%): access to oxygen‐rich water layers that are indispensable for egg development vs. smaller size of larvae at first feeding, since the saturated lipids contained in oil globules essentially serve very little to tissue construction.

Induk ikan Botia (Botia maeracantha Bleeker) hasil tangkapan dari Sungai Batang hari Jambi, telah diimplantasi dengan hormon LHRH-a des Gly10 [D - Ala6] Sigma Chemical pada dosis 100, 150, 200 pg/kg bobot badan induk. Percobaan dilakukan pada awal Januari 1995.

Mahseer is an economically important fish in the world with a distribution from the Himalayan Mountains up to Southeast Asia. One species of Masheer is Tor soro in the Indonesian Archipelago. For a long time, T. soro has been collected from the wild and now is becoming rare. In addition, the degradation of its habitat is another problem. Hence, it is urgent that this species is saved from extinction. Domestication of T. soro from North Sumatra has been conducted since 1996. This paper reports the results of domestication of T. soro starting from collecting live specimens, genetic and morphometric characterizations, evaluation to breeding, and growing out. In 2010, domestication was successful to produce a second generation of young broodstocks and now the breeding technology is being shared with several provinces where T. soro exist.