Determining the type of rearing tank (container) is an important aspect in aquacultur activities, including the production of silver pompano Trachinotus blochii larvae. This activity aims to compare the use of different types of tanks (concrete tank and fiberglass tank ) on the survival rate of silver pompano Trachinotus blochii larvae. These observations were carried out during three cycles (October – December 2023) at the Batam Mariculture Center. The treatment applied was larval rearing using concrete tank and fiberglass tank . The concrete tank used has an effective volume capacity of 8 m3 in the form of a square, while the fiberglass tank has an effective volume capacity of 5 m3 in the form of a tube/cylinder. The larval rearing period is 20-25 days per cycle. The main parameter observed was the survival rate of silver pompano Trachinotus blochii larvae each cycle. Other parameters observed were the average larval length (initial and final of observation) and the water quality of the rearing media consisting of temperature (°C), salinity (‰), dissolved oxygen/DO (mg/L), and pH.
The results showed that the survival rate of silver pompano Trachinotus blochii larvae in concrete tank was 23.33% - 26.39%, while in fiberglass tank was 16.00% - 22.22%. The final length achieved for the two treatments did not have a significant difference, with values of 1.52 cm - 1.58 cm (concrete tank) and 1.53 cm - 1.65 cm (fiberglass tank). The water quality parameter values in each treatment were still within the range of safe and optimal values for larval growth during three rearing cycles. The values for temperature: 29.5°C – 31.2°C (concrete tank) and 28.0°C – 30.1°C (fiberglass tank); salinity: 29.0‰ – 30.2‰ (concrete tank) and 29.0‰ – 29.9‰ (fiberglass tank); DO: 5.0 mg/L – 5.5 mg/L (concrete tank) and 4.6 mg/L – 5.6 mg/L (fiberglass tank); and pH: 7.01 – 8.32 (concrete tank) and 7.20 – 7.98 (fiberglass tank). From the results of this activity, it can be concluded that silver pompano Trachinotus blochii larvae reared in concrete tank have a higher survival rate (SR) than fiberglass tank.