Study on growth performance of female mud crab (Scylla serrata) under three different types of feed in recirculating aquaculture system (RAS) (At the research institute of aquaculture No.2 (RiA2))

Abstract

Currently, the price and consumption market of commercial crab is quite stable. In recent years, farmers have gained high profits due to the stable price of mud crabs (Scylla serrata). Crab farming models are usually traditional models. In order to achieve the goal of technical advancement, and support for researching on feed, it is appropriate to use new systems such as recirculation systems. This study aimed to determine the proper type of feed on the fattening of female mud crab (Scylla serrata) in RAS system. Specifically, the goal was to identify the effects of different feed types on female mud crab growth and roe production. It served as a reference for later research on mud crab cultivation. In the experiment, the recirculation system was a reasonable choice used to manage and control the quality of water resources to help high survival rates and increase productivity. Mackerel (Decapterus sp.), Nile Tilapia (Oreochromis niloticus), and Razor clam (Solenidae sp.) were three types of feed that used in the experiment, each treatment had 12 crabs. Test kit NH3/NH4 Sera was used to determine the ammonium/ammonia concentration and assess nitrification in RAS system. After 45 days of the experiment, Mackerel (Decapterus sp.) feeding gave the fastest growing of crab and Razor clam (Solenidae) feeding gave the slowest growing of crab. The best growth, highest nutrient and crab roe’s level were produced on crabs that fed with Mackerel (Decapterus), while the lowest was produced on the crabs that fed with Razor clam (Solenidae). The application of RAS is effective in the experiment, helping to increase the proportion of beneficial bacteria while the harmful bacteria are eliminated by the biofilter system, cost saving and risk reduction greatly. Keywords: RAS, female mud crab (Scylla serrata), crab roe, Mackerel (Decapterus sp.), Nile Tilapia (Oreochromis niloticus), Razor clam (Solenidae sp.), nitrification, survival rate, growth performance, Nitrosomonas, Nitrobacter …