Antioxidant biomarker profile of chironomid larvae from carp ponds: Evaluation of the effects of different fish feeding patterns

Abstract

A 102-day feeding trial was conducted to evaluate the effects of four different fish feeding patterns on carp pond water quality and antioxidant biomarkers [superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), Glutathione reductase (GR), Glutathione S-transferase (GST) and Thiol groups (SH)], protein content and biomass of the midge Chironomus plumosus. Farmed fish were fed two commercial diets: Soprofish 25/7 Standard (containing 25% protein and 7 % fat) and Soprofish 32/7 Profi Effect (containing 32 % protein and 7 % fat). These feeds were combined during a feeding trial in four different feeding patterns, designated as A, B, C and D. In feeding pattern A, the fish received Soprofish 25/7 Standard throughout the experiment and in feeding pattern D, Soprofish 32/7 Profi Effect. During feeding patterns B and C, a mixed feeding pattern was used, alternating between lower and higher protein diets. The study revealed no significant effects (P > 0.05) of the feeding regimens on water quality, so their effects on C. plumosus larvae can be evaluated independently. The activities of the chironomid enzymes CAT and GR showed a clear statistically significant dependence on the feeding pattern (P 0.05). Overall, our results suggest that long-term supplementation with a highly concentrated protein diet may have preventive effects against oxidative stress and support the use of C. plumosus as a model for assessing the effects of organic pollution on pond zoobenthic fauna.

Keywords

• Antioxidant enzyme
• Carp aquaculture
• Chironomus plumosus
• Feeding pattern
• Water quality