Growth Performance, Immune Responses and Genetic Characteristics of Common Carp (Cyprinus carpio) Exposed to Limonene-based Pesticides

Abstract

Botanical pesticides are increasingly used as alternatives to synthetic pesticides, yet their effects on non-target aquatic organisms require careful assessment. This study aimed to determine the effect of a botanical pesticide containing limonene as the active ingredient on the growth and immunity of common carp (Cyprinus carpio) fry. It was conducted in February-March 2025 at the Ciparanje Hatchery, Padjadjaran University, with four limonene concentration treatments: 0 ppm (control), 0.9 ppm, 1.3 ppm, and 1.6 ppm over a 28-day period. The parameters observed included growth, survival, and haematological responses. The results showed that exposure to limonene had a negative impact on the physiological performance of the fish. The highest survival rate was observed in the control group (58±7.64%) and the lowest at 1.6 ppm (42±8.33%). The highest growth in length and weight was also observed in the control group, at 1.29±0.02 cm and 1.75±0.02 g, respectively. Conversely, the lowest growth occurred at 1.6 ppm. The highest leukocyte count was found at 1.6 ppm on day 10 (19.56×10⁴ cells/mm³), while the highest erythrocyte count was in the control group on day 0 (1.04×10⁶ cells/mm³) and the lowest at 1.6 ppm (0.44×10⁶ cells/mm³). PCR-RAPD analysis revealed differences in genetic similarity patterns among treatments, with the 1.3 and 1.6 ppm treatments forming a closer cluster based on dendrogram analysis. These findings highlight the importance of prudent use of botanical pesticides in aquaculture and appropriate management of pesticide exposure in aquatic environments to minimise potential impacts on fish health and support sustainable aquaculture and ecological management.