Jayasakti common carp ( Cyprinus carpio ) is a local variant of common carp produced by Jambi Freshwater Aquaculture Development Centre (JFADC), this variety has been widely accepted by people on the island of Sumatra. Jayasakti common carp nursery activities are often conducted in the local community and in small hatcheries using extensive facilities, especially during rearing phase of nursery larvae. In open ponds / containers care fish disease problems are often occurred , besides that it requires a large area of land. To optimized land area and water resources efficiently, the larval rearing of Jayasakti common carp larvae conducted in a controlled container with round tub shape from water resistance tarpaulin.
This rearing system is an alternative nursery for common carp larvae with controlled fish health management . Rearing activities using controlled containers are conducted to suppress fish disease attacks. The diseases always had a negative impact for the production of Jayasakti common carp at Jambi Freshwater Aquaculture Development Centre (JFADC) are parasitic pathogens, it often encountered when rearing activities are carried out both in open ponds or public waters. The use of controlled tanks will make it easier to implement fish and environmental health management. By u sing the controlled tank, the parasitic diseases will be easier to control, if it left unchecked, will open up opportunities for secondary infections. Rearing activities are conducted on a round tarpaulin tub recirculation system (10 tons volume), with 3 different density levels. B1: 100,000 fish , B2: 150,000 fish and B3: 200,000 fish . The test fish used in this activity were Jayasakti common carp larvae that were 1 day old from hatching with a weight of between 0.06 ± 0.015 gr which were reared in round tanks for one month with given natural and artificial food for 3 times a day. Fish are sampled every week to measure the length and weight of larvae, then fish diseases is monitored periodically . Disease control activities are counducted by giving commercial probiotics in a container (dose 1 ppm) and using salt (dose 1 ppt). Larvae were sampled are collected for statistical analysis.
The test results showed that nursery of Jayasakti carp larvae in B1 provided 50% survival (50,000 individuals) for 30 days, better than treatments of B2 and B3. The health status of the fish that attacked the disease was relatively low in B1 tank , with moderate ectoparasite attacks (prevalence 45.55-68.45%) and moderate intensity (50.35-72.25 parasite/fish) during rearing period.