| dc.description.abstract | Oligochaeta worm contain protein of 65%, fat 15%, and carbohydrate 14%, therefore very well when given to the fish larvae during nursery period. But, the availability of oligochaeta worm are very limited especially in Belitung which has 10 hatchery. So that, it needs oligocheta worm cultivation to meet the demand. The research used closed system which mean wasted water from. The purpose of this research to determine the best stocking denstiy of oligochaeta worm between 2600,3600, and 4600 indvidual/m2 with the system based on the biomass, growth rate,and economic efficiency. The research was perfomed in April until August 2011 at the Balai Benih Ikan Air Tawar Belitung Timur. The medium used are a mixture of fine mud and chicken manure. The worm was spread and fermentation manure chicken fertilized added every day about 1 kg/m2. The worm was cultured during 60 days and took as samples every 10 days. The observation indicated that the maintanence of oligocaeta worm with closed system produced the level of ammonia contain was higher and dissolve oxygen contai was lower than using opened system. In this condition, the worm was able to survived even thought feeding habit and reproduction is inhibited. Highest population and biomass occured on 50th day with stocking density 4600 individual/m2 as much as 255091.61 individual/m2 and 1275.46 g/m2. Highest biomass growth rate occured in 4600 individual/m2 as much as 25.05 g/m2/day. Stocking density 4600 individual/m2 got the profit as much as Rp 5 828 525, R/C ratio 1.04, PP for 6.13 years, BEP (Rupiah) Rp 154 585 260 and BEP (units) 937 kg, and HPP Rp 72 389. | en |
