Teknologi pembesaran cacing Nereis Dendronereis pinnaticirris (Grube 1864)

Abstract

Minimum requirement of polychaetes, including the nereis Dendronereis pinnaticirris, as feed for shrimp broodstocks in Indonesian hatcheries on 2011 was 6,947 tons. In the next years it is forecasted that the need will increase. Nereis culture aims to meet the demand for shrimp hatchery, and for preserving the broodstocks and the environment indirectly. Level of salinity, substrate type, density, and type of feed affect the productivity of polychaetes. Data of optimum salinity, optimum substrate, optimum density, and the best feed for nereis D. pinnaticirris were not exist. Klekap powder was chosen as a test feed because of reason that the stomach content of nereis was similar to klekap. Klekap was the best feed for milk fish fry compare to plankton. This study included four consecutive trials on the topic: salinity, substrate, density, and feed. D. pinnaticirris with weight closed to 150–200 mg adapted to 15 or 20 ppt salinity and sterilized natural substrate for 30 days were used as test animals. Test animals kept in an aquarium measuring 40x40x30 cm with a substrate according to treatment with a depth of 10 cm and aerated water in 8.5 cm depth for 35 days trial. Experiment I showed that the daily growth rate, the feed efficiency, the protein retention, and the productivity reached the highest at 20 ppt salinity of media. It was found an equation as y = 0.00005778x2 - 0.032x + 1.643; y = 1, so x = 20 ppt; where y = osmotic actiity rate and x = salinity. Experiment II showed that test animals were constantly move if they could not find the hole or had no ability to make the hole. Substrates with grains of 63250 μm in diameter in salinity of 20 ppt significantly (P <0.05) produced better daily growth rate, better protein retention, better survival rate, better production, and better productivity. Experiment III showed that the highest absolute biomass growth was in density of 1,000 individuals/m2 in the amount of 4,064.0 g. Stress occured in first day which was indicated by an increase of glucose content and a decrease of glycogen content. Glucose content in the density of (250; 500; 1,000; 2,000: 4,000) individuals/m2 were (18.0; 20.0; 19.0; 29.0; 48.0) mg/dL respectively; the glycogen content were (103.307; 102.722; 81.562; 65.781; 77.804) mg/g respectively. In the 18th day and the 35th day, they returned to normal in all treatments. Experiment IV suggested that klekap powder contained ARA. ARA produces prostaglandin PGF2alpha that has ability to promote muscle growth. The use of 20 ppt salinity, soil substrate with 63–250 μm in diameter grain, density of 1,000 individu/m2, and feed with a combination of 75% commercial feed and 25% klekap powder were significantly (P <0.05) produced the daily growth rate of 0.58%/day , the feed efficiency of 48.63%, the protein retention of 26.09%, the lipid retention of 5.28%, and the productivity of 27 g/m2/30 days.