Fish epidermal mucus analytes with reference to physiological threats: non- intrusive approach to evaluate health status of carp fishes

Document Type : Original research

Authors

• Anita Bhatnagar
• Kirti Budhalia

Department of Zoology, Kurukshetra University, Kurukshetra, Haryana, India

10.22034/iar.2023.1983914.1426

Abstract

Fish health can influence important population-level processes, especially those trying to deal with challenges posed by the natural environment, and growth, which in turn affect stock productivity. Two experiments were conducted to evaluate the metabolites of epidermal mucus in response to two threats of environment faced by the fishes: starvation and pathogenic attack ; with the aim to check the alteration in values of innate immune parameters in the epidermal mucus of three Indian major carps, Catla catla, Labeo rohita, and Cirrhinus mrigala. Study showed that, in all three species the amount of mucus secretion and parameters like protein, carbohydrate and lipid of skin mucus altered after both the challenge trials and their concentration differed with respect to species. In particular, immune parameters including lysozyme, alkaline phosphatase and protease increased after both challenges (starvation and pathogenic attack) to face the stress. In contrast myeloperoxidase activity decreased significantly (p ˂ 0.05) after the challenge of starvation but its value increased with pathogen challenge. Variations in mucosal parameters thus could be employed as possible non-invasive biomarkers for studying fish physiology in response to environmental stresses and as an integrated approach to assess the particular species response to the specific condition.

Keywords

• Carp fishes
• Mucus metabolites
• Environmental stress
• Starvation
• Fish pathogen

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