Study of the hatchability and survival rate of rainbow trout larvae in nanosilver troughs

Objective: Under natural conditions, the percentage of young fish that survive from egg to maturity is extremely low. However, under well hygiene and modern conditions the survival is considerably higher. Because of the antibacterial, antifungal and antiviral activities of nanosilver particles the aim of this study was to assess the effect of nanosilver troughs (Nanocid, NanoNasb Com., Iran) on the rate of hatchability of rainbow trout egg and the survival of produced young fish up to 1 g. Method & Materials: A number of 24365 fertilized rainbow trout eggs were incubated in four trays accommodated in a nanosilver trough provided at water temperature of 12◦C using spring water. A number of 41411 fertilized eggs were incubated in nine trays accommodated in three fiberglass troughs as the control groups. Ova care and development up to hatch were control daily. Also, the produced larvae were grown up to 1 g. The survival rate of fertilized eggs up to hatch was measured. Also, the survival rate and weight of the produced young fish were assessed up to 1 g body weight. Results & Conclusion: The obtained results showed that the survival rate of fertilized eggs up to eyed-egg stage was 92.3% compared to 80.9% for the control groups (P<0.05). Also, the survival rate of eyed-eggs up to hatch stage was 75.18 % in nanosilver trough compared to 64.82% for the control groups (P<0.05). Totally, the survival rates of hatch were 69.4% for nanosilver trough compared to 52.5% for the control groups (P<0.05). Also, the survival level of the produced young fish kept in nanosilver trough up to 1 g body weight was 91.8% while those of control groups were totally 87.3% (P>0.05). In addition, the final average weight of larva produced in nanosilver trough was 1.12 g while that of control group was 1.03 g (P>0.05). The obtained results showed that use of nanosilver troughs can significantly improve the hygiene condition of trout hatching resulting in higher hatchability of incubated eggs.

کلیدواژه ها:

nanosilver ، hygiene condition ، rainbow trout ، hatching ، hatchability of egg