Stocking Density and Feed Rate Effect on Growth and Survival of Litopenaeus vannamei in a RecirculatingIndoor Tank System

摘要

Shrimp farming is a major industry in tropical and subtropical areas around the world. However, there are concerns about the ecological sustainability of the industry due to factors including the discharge of nutrient rich effluents using earthen pondproduction systems. Semi-intensive and intensive shrimp farming with high stocking density, depend largely upon commercially formulated high quality balanced feed contributing 55-60% of the total production cost (Mohanty, 2001). It has been reported that a significant portion of the feed provided to the cultured shrimp remain unutilized due to various reasons (Martinez-Cordova et al., 1998; Mohanty, 2001). The excess and unutilized feed crumbles and disintegrates in culture water and is a potential cause for water quality deterioration in closed aquaculture systems (Funge-Smith and Briggs, 1998; Mcintosh et al., 2000; Viadero and Noblett, 2002; Cohen et al., 2005). The nutrient rich effluent in open aquaculture systems is a potential cause for negative environmental impacts (Thakur and Lin, 2003; Cohen et al., 2005). Unused feed with the fecal matter contribute primarily to the solids load and high oxygen demand in the culture environment. High levels of critical water quality parameters in culture systems have been shown to affect shrimp growth and survival (Cohen et al., 2005; Mcintosh et al, 2001; Mishra et al., 2008). Feed is the major source of pollution in aquaculture production systems (Kaushik and Cowey, 1991; Lawrence et al., 2001). Pollution from feeds may be due to an inadequate feed in terms of nutrient quality and density or to an inadequate feed management program (e.g., overfeeding or