EFFECT OF FORMULATED FEED ON GROWTH PERFORMANCE OF MUD CRAB IN SOFT SHELL FARMING SYSTEM

Abstract

The commercial farming of soft-shell crab has been going on in Bangladesh for nearly 10 years, little research has been conducted regarding formulated feeds. The present study was conducted to develop practical formulated diets for soft-shell mangrove crab farming. Presently, there is an urgent need to replace “trash fish” with manufactured diets. In this study, growth performances of mud crab were evaluated by providing feeds namely trash fish; commercial shrimp feed and formulated feed. Individual crabs were placed in 54 buckets in the field research facility at the Institute of Coastal Bio-Diversity, Marine Fisheries & Wildlife Conservation of Chittagong Veterinary and Animal Sciences University, situated in Doriyanagar, Cox’s Bazar. A feeding trial was conducted where the feeding frequency was 5% of the body weight at daily, one day interval and two day interval. The growth of crabs fed the trash fish was not significantly different from the formulated diet, both near 0.70 g/day while the growth rate when fed commercial shrimp feed diet was significantly lower, 0.34g/day. Trash fish provided the best weight gain (47.2±8.334 g), carapace width gain (16.1±2.25 mm) and molting performance followed by formulated feed, which was significantly indifferent from trash fish (P >0.05). Crabs fed with trash fish required shortest number of days for molting (26.3 days). Crabs fed with trash fish had a higher survival rate (44.44%) than commercial shrimp feed (38.89%) and formulated feed (16.67%). The results on feeding trial showed, feeding at two days interval was better in survival (61.11%), carapace width gain (13.89± 0.19) and weight gain (67.88± 10.12%). The results of the present study demonstrated that mud crabs accept formulated feeds but they need to be domesticated. Hence, the development of specific diets for crabs is technically possible by conducting further study on the performance of mud crab at different protein levels and by inclusion of different protein sources in artificial feed.