Stress response of Asian redtail catfish (Hemibagrus nemurus) fingerlings subjected to various pH exposure

Abstract

Asian redtail catfish (Hemibagrus nemurus) is one of the economic freshwater fish species in Indonesia. There is still a lack of information regarding water quality tolerance of Asian redtail catfish. Therefore, this study was conducted to obtain information on the stress response of Asian redtail catfish under various pH exposures. The experimental fish was the second generation of domesticated Asian redtail catfish from the Cirata population (Length: 11.7 ± 0.6 cm; Weight: 13.2 ± 1.6 g). The pH treatment in this experiment was low pH (4-5), optimal pH (6-9), and high pH (10-11) with three replicates in each treatment. Stress response was observed by measuring blood glucose and plasma cortisol. Moreover, fish behavior and survival were also observed. Results showed that glucose level of Asian redtail catfish fingerlings was higher at low pH treatment (258.8 ± 75.1 mg/dL) than optimal (58.7 ± 7.5 mg/dL) and high pH treatment (151.0 ± 21.5 mg/dL) (P<0.05). Cortisol level at low (34.02 ± 3.16 IU) and high pH (32.88 ± 13.85 IU) was significantly higher than optimal pH treatment (12.56 ± 5.18 IU) (P<0.05). Low and high pH exposure to Asian redtail catfish increased their cortisol and glucose levels, which will lead them to mortality.