Survival rate and growth rate of milkfish (Chanos chanos, Forsskal 1775 ) seeds in the acclimatization process at Ir. H. Djuanda Reservoir

Abstract

Abstract Milkfish is one of the important economical fish species that usually lives and cultivated in estuarine areas. However, milkfish can adapt to habitat with salinity ranging from 0 - 40 ppt. Therefore, milkfish is a potential choice of introduced fish in freshwaters. This study aims to determine the survival rate and growth rate of milkfish seed in the waters of Ir. H. Djuanda Reservoir. H. Djuanda. The study was conducted experimentally in November – December 2017, every week for five weeks in floating net cages with a size of 7 x 3 m and depth 0.75 m at Ir. H. Djuanda Reservoir with three treatments of densities that are 4,000; 6,000 and 10,000 seeds. The size of milkfish seeds used was 3-5 cm because it was able to adapt in freshwaters. The milkfish was cultivated by the extensive system without a commercial feed so they only use natural food. The results showed that the number of dead milkfish increased with increasing density and the highest mortality occurred on the day 7th in 10,000 density treatment. The milkfish seed mortality began to decrease on the day 9th of the trial and the deaths did not occur again on the day 19th-21st. The highest survival rate was 79.21% for 6,000 densities. The highest length growth rate was 0.93 mm/day for 6,000 densities. The smallest estimated investment was 10,000 densities, but it has the largest losses due to seed death. Because the condition was dense, there was competition for food, oxygen, and space. Therefore, seed acclimation is carried out in stages.