Performance of crustacean and insect meal based diets on the growth and digestive enzyme profile of pearlspot Etroplus suratensis (Bloch, 1790)

Influence of crustacean and insect meal on pearlspot, Etroplus suratensis

Abstract

A feeding trial of 75 days was conducted in tanks to study the performance of shrimp
head meal (SM), crab shell meal (CM) and silkworm pupae meal (SWP) on the growth and
digestive enzyme profile of pearlspot, Etroplus suratensis. Four iso-nitrogenous diets with
31.5% crude protein replacing 50% fishmeal (FM) in the diets were formulated viz., SM (T1),
CM (T2), SWP (T3) and a control (C). Pearlspot advanced fry, 2 cm in length and 1.1 g in
weight, was stocked at 60 nos per tank. After 75 days of the experiment, feed conversion
ratio (FCR), feed efficiency ratio (FER) and protein efficiency ratio (PER) were observed to be
significantly better (p<0.05) in all treatment groups (T1, T2 and T3) than in control (C). T2 (CM)
fed fishes exhibited a maximum specific growth rate (SGR) of 3.25±0.09, and significantly
higher (p<0.05) weight gain (11.54±0.78 g) than T1, T3 and control. In enzyme assays, T2 (CM) fed
fishes exhibited significantly higher (p<0.05) protease activity than other treatments.
Lipase activity was significantly higher (p<0.05) in T3. However, there was no significant
difference with control diet-fed fishes. Significantly higher (p<0.05) activities of amylase,
malate dehydrogenase (MDH) and lactase dehydrogenase (LDH) were observed in all the
treatments compared with control. The outcomes of the present study indicate that crab
meal (31.5% CP) could be effectively utilised as a 50% replacement for fishmeal in the diet
of E. suratensis advanced fry for higher yields.

Keywords:
Crab meal, Enzyme activity, Growth, Shrimp meal,
Silkworm pupae meal