Eficiência de bandejas na alimentação de juvenis do camarão branco, Litopenaeus vannamei (BOONE, 1931) avaliado por meio de imagens subaquáticas

Abstract

Farming of marine shrimp is done almost entirely using industrially-compounded feeds. Feeds have a high impact on the production costs of farm-raised shrimp. The efficiency of feed use in shrimp farms is influenced by the distribution method adopted during shrimp feeding. The present study aimed at determining the effectiveness of the feeding trays in the feeding of juvenile shrimp, Litopenaeus vannamei. Two types of trays were evaluated, one hand-made, produced from recycled car tires and the other industrially, using recycled thermoplastic materials, molded through injection. The hand-made feeding tray was tested with and without the accessory called "truque", a PVC receptacle to prevent feed losses. Feed losses during the launching of the feeding tray in water were determined in a tank with acrylic walls with a total volume of 487.6 L. In order to determine the number of shrimp with access to feeding tray, a circular tank with 3,000 L was used. Images were captured with an underwater camera, and later analyzed. Results indicated that the industrially-manufactured feeding tray took longer to reach the tank bottom. The percentage of feed in water was statistically higher when employing the hand-made tray. However, feed losses were practically eliminated while employing the "truque". The industrial feeding tray resulted in lower losses of feed in water, but it was less accessible to shrimp due to its higher edges. The hand-made tray equipped with the "truque" resulted in the greatest efficiency among all devices evaluated.