Growth response, digestive enzyme activity and stress enzyme status in early stages of an endangered fish, Notopterus chitala (Hamilton, 1822) fed with live feed and formulated diet

A 60 days experimental trial was conducted to study the effect of different diets on growth and survival of near threatened species, Notopterus chitala fry. A total of 450 numbers of fry (0.88 +/- 0.01 g) were randomly stocked in 6 treatments in triplicates. The experimental fishes were fed with various live feeds viz., live Tubifex (TF), un-enriched Artemia (UA), enriched Artemia (EA), un-enriched Moina (UM), enriched Moina (EM) and commercial feed (CF). Live feed based treatments showed significantly higher growth rate, digestive enzyme activity and survival than commercial feed. Among the live feeds, enriched live feeds contributed better growth performance with the highest average body weight (4.59 +/- 0.17 g) and survival (72.66 +/- 2.90%) observed in enriched Artemia fed fishes. The digestive enzyme analysis revealed that there was no significant difference in the intestinal amylase activity among the treatment groups whereas, the highest protease (4.22 +/- 0.16 U mg protein(-1) min(-1)) and lipase activity (1.13 +/- 0.02 U mg protein(-1) min(-1)) was observed in EM fed treatment group. The reduced level of SOD, catalase, AST and ALT activity was recorded in liver tissue of EA and EM fed group which indicates a lower level of stress in experimental fishes when fed with enriched diet. The study found that the enriched live feed is having a positive impact on growth and survival as compared to its un-enriched counterpart and further Artemia is the most preferred live feed for N. chitala fry.