Comparative analysis of hematological characteristics of some freshwater fish species from wild and cultured environments

Abstract: Hematology serves as a valuable diagnostic tool in aquaculture for assessing fish health, monitoring environmental conditions, and evaluating responses to nutrition and management practices. Therefore, this study aimed to compare the hematological characteristics of three economically significant fish species such as Gangetic mystus (Mystus cavasius), stinging catfish (Heteropneustes fossilis), and walking catfish (Clarias batrachus) obtained from wild and cultured habitats. Wild and cultured fish specimens were collected from the Turag river and a commercial fish hatchery, respectively. Blood samples were extracted from the caudal peduncle and stored in heparinized tubes for hematological examination. The results demonstrated that the cultivated environment showed increased dissolved oxygen, pH, and temperature, along with elevated electrical conductivity, whereas the wild environment presented higher concentrations of nitrite and ammonia. Among the hematological parameters, no significant differences (p > 0.05) were observed in HCT and MCHC content between the wild and cultured fish. However, WBC and RBC varied significantly (p < 0.05) across all the species in both environments. Lym, Gra, Hb, and PLT counts in stinging catfish varied significantly between natural and cultured habitats. For Gangetic mystus, Lym, MCV, and MCH differed significantly (p < 0.05) while, walking catfish exhibited insignificant variations in terms of any hematological parameters except WBC and RBC. These findings underscore that hematological parameters are sensitive to environmental conditions and can serve as reliable indicators of fish health. The species-specific variations observed further suggest that different fish respond uniquely to wild and cultured environments, highlighting the importance of species-based assessments in environmental monitoring and aquaculture management. 

Keywords: Cultured fish, hematology, immune response, water quality, wild fish