Fish immune system and its nutritional modulation for preventive health care

Under intensive culture conditions, fish are subject to increased stress owing to environmental (water quality and hypoxia) and health conditions (parasites and infectious diseases). All these factors have negative impacts on fish well-being and overall performance, with consequent economic losses. Though good management practices contribute to reduce stressor effects, stress susceptibility is always high under crowded conditions. Adequate nutrition is essential to avoid deficiency signs, maintain adequate animal performance and sustain normal health. Further, it is becoming evident that diets overfortified with specific nutrients [amino acids, essential fatty acids (FAs), vitamins or minerals] at levels above requirement may improve health condition and disease resistance. Diet supplements are also being evaluated for their antioxidant potential, as fish are potentially at risk of peroxidative attack because of the large quantities of highly unsaturated FAs in both fish tissues and diets. Functional constituents other than essential nutrients (such as probiotics, prebiotics and immunostimulants) are also currently being considered in fish nutrition aiming to improve fish growth and/or feed efficiency, health status, stress tolerance and resistance to diseases. Such products are becoming more and more important for reducing antibiotic utilization in aquafarms, as these have environmental impacts, may accumulate in animal tissues and increase bacterial resistance. This study reviews knowledge of the effect of diet nutrients on health, welfare and improvement of disease resistance in fish.

Nutrition and health of aquaculture fish.

Reviews Environmental Contamination and Toxicology

Non-starch polysaccharides and their role in fish nutrition – A review

Abstrcat Immunostimulants are valuable for the prevention and control of fish diseases in aquaculture.Several immunostimulants such as polysaccharide and micronutritional factors and their effective mechanism are reviewed, meantime, existing problems in immunostimulant application and future research tendency are described.

Current Research Status of Fish Immunostimulants

Effect of short term exposure of fenvalerate on biochemical and haematological responses in Labeo rohita (Hamilton) fingerlings

Pigmentation is one of the important quality attributes of the fish for consumer acceptability. Carotenoids are responsible for pigmentation of muscle in food fish and skin colour in ornamental fish. As fish is not capable of synthesizing carotenoids de novo there is a need to incorporate carotenoids in the diet of cultured species. Since synthetic carotenoids are known to have deteriorating effects on the environment, there is a great demand for inclusion of natural carotenoids in aqua feed to achieve bright coloration in fish. The possible use of naturally available carotenoid rich ingredients such as microalgal pigments (Chlorella vulgaris Beijer, Haematococcus pluvialis, Dunaliella salina (Dun.) Teodor), yeast extract (Phafia rhodozyma, Xanthophyllomyces dendrorhous), marigold, capsicum, etc. has been discussed in this article.

http://nopr.niscair.res.in/bitstream/123456789/7831/1/NPR%206%281%29%2046-49.pdf

Use of natural carotenoids for pigmentation in fishes

Dietary zinc promotes immuno-biochemical plasticity and protects fish against multiple stresses.

Oxidative and cellular metabolic stress of Oreochromis mossambicus as biomarkers indicators of trace element contaminants

A 60-day experiment was carried out to delineate stress mitigating and immunomodulatory role of dietary pyridoxine (PN) in Labeo rohita fingerlings exposed to endosulfan. Two hundred and seventy fingerlings were randomly distributed into six treatments in triplicates. Five iso-caloric and iso-nitrogenous purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T0 (10 mg PN+without endosulfan), T1 (0 mg PN+endosulfan), T2 (10 mg PN+endosulfan), T3 (50 mg PN+endosulfan), T4 (100 mg PN+endosulfan) and T5 (200 mg PN+endosulfan). The role of pyridoxine on stress mitigation and immunomodulation was assessed by biochemical and haemato-immunological parameters like aspartate aminotransaminase, alanine aminotransaminase, lactate dehydrogenase, malate dehydrogenase, superoxide dismutase and catalase were significantly (P<0.05) lower while acetylcholinesterase was significantly (P<0.05) higher in pyridoxine-fed groups. Erythrocytes count, haemoglobin content and total serum protein, albumin, globulin, nitroblue tetrazolium and lysozyme activity were significantly (P<0.05) higher while cortisol and blood glucose were decreased significantly (P<0.05) in pyridoxine-fed groups. Percentage survival after challenge with Aeromonas hydrophila was highest in T0 group. The results obtained in present study indicate that dietary pyridoxine supplementation at 100 mg PN kg−1 diet reduces the endosulfan-induced stress and triggers immune response in L. rohita fingerlings.

Sanjay Kumar Gupta

Papers

Effect of short term exposure of fenvalerate on biochemical and haematological responses in Labeo rohita (Hamilton) fingerlings

Use of natural carotenoids for pigmentation in fishes

Dietary zinc promotes immuno-biochemical plasticity and protects fish against multiple stresses.

Oxidative and cellular metabolic stress of Oreochromis mossambicus as biomarkers indicators of trace element contaminants

Stress mitigating and immunomodulatory effect of dietary pyridoxine in Labeo rohita (Hamilton) fingerlings