Growth response and gill tissue damages of common carp (Cyprinus carpio) juveniles exposed to Neem Azal biopestiside (Azadirachtin indica)

The chronic effects of Neem Azal on growth parameters, survival and gill morphology of common carp (Cyprinus carpio) with average weight of 10.56 ± 0.12 g were determined. A total of 120 fish were distributed equally between three treatments and a control group, with three replicates each. To determine the chronic effect, sublethal concentration of poison, 0.12 (10% LC50), 0.24 (20% LC50), 0.36 ppm (30% LC50), was selected and fish were exposed to these doses for 28 days. Increasing doses of Neem Azal had a significant effect on growth parameters, as the growth declined significantly when poison dose increased (P0.05. Reactions such as irregular swimming, abnormal behavior, nervous reaction to external stimulator, increased opercular beating ​​and anorexia were observed during the test. Damage to the gill tissue also increased as the poison levels increased. Generally, the negative effects of Neem Azal on growth parameters and gill morphology of common carp were observed as biopestiside levels increased.