Histological alterations in the intestine of threatened Asian catfish, Clarias batrachus fed with different types of fats through semi-purified diets.

Abstract

In the present study the intestinal sac method (ex vivo) was used to evaluate the interactions between different fats in the diets in the gastrointestinal (GI) tract of Asian catfish, Clarias batrachus. The catfish was fed with six diets (FISOL, F1; BETAL, F2; SOYAL, F3; LINOL, F4; MIXOL, F5; SATOL, F6) and a control (NATFO, F7) with natural food. FISOL BETAL, SOYAL, LINOL and SATOL diets contains 10.0% fish oil, beef tallow, soybean oil, linseed oil and saturated oil in F1, F2, F3, F4 and F6 diets, respectively. The MIXOL, F5, contains 2.5% each of fish oil, beef tallow, soybean oil, linseed oil. Histological changes following dietary interventions were assessed by microscope. Control samples and samples fed with different fat had a similar appearance to intact intestinal mucosal epithelium, with no signs of cellular damage. However, C. batrachus fed with fish oil showing increased number of villi. Fishes fed with beef tallow showing more space at the base of villi and longitudinal muscles are seen degenerated fishes fed with soybean oil depicting more spaces at the base of the villi and more goblet cells are seen. Linseed oil fed fishes showing appearance of enlarged spaces between circular muscles and base of villi. Intestine of C. batrachus fed with mixed oil showing elongated lumen in villi and enlarged circular muscles are normally seen and less prominent. Intestine of C. batrachus fed with saturated oil showing elongated lumen in villi and increased in numbers of villi and circular muscles less seen, longitudinal muscles are seen normally and serosa layer is reduced showing some detachment of base of villi observed with more spaces and vacuolation. The results suggests that supplementation of different fats has direct relation with the histological alterations in the fish intestinal tissues .