Different of aeration rate on hatching rate, abnormality, yolk sac absorption, and absolute length of newly hatched larvae of mahseer (Tor soro)

Mahseer, Tor soro is a local freshwater fish species that has an economical value in Asia including Indonesia. Environmental factors such as aeration, temperature, pH, and salinity affect the high of abnormality and unstable hatching rate. The purpose of this experiment is to determine of aeration rate on hatching rate, abnormality, yolk sac absorption, and absolute length of newly hatched larvae. The treatment of aeration rate are as followed: A) 0 mL/minute; B) 500 mL/minute; C) 1000 mL/minute; D) 1500 mL/minute; E) 2000 mL/minute. The result shows that the aeration rate affects the abnormality, yolk sac absorption, and absolute length of newly hatched larvae (p<0.05). The abnormality at 0 mL/minute was the highest (23.23 ± 0.26%) and the lowest (2.84 ± 0.36%) at 500 mL/minute. The yolk sac absorption 0.1268 ± 0.0056 mm 3 /day at 1500 mL/minute was the highest compared to the others (p<0.05). The absolute length of newly hatched larvae at 1500 mL/minute (4.6435 ± 0.2518 mm) was the highest compared to the others (p<0.05). The dissolved oxygen value was increased by increasing the aeration rate. The optimal aeration rate for egg incubation should be adjusted to 1000 mL/minute to reduce the abnormality and optimize for larval grow.