Rendimento do filé de Tilápia do Nilo (Oreochromis niloticus) criada em tanques-rede.

Abstract

In Brazil the creation of tilapias fish in tank built with nets presents high potential of production. The Northeast region may explore from 1.0 to 1.5 million hectares in this activity. The objective of this work was to evaluate the effect of different classes of weight of tilápia of Nile, Oreochromis niloticus, created in tank-net, in relation to the quantity of filet with skin or without. The fishes breeding was in the artificial lake of Sao Gonçalo, in Sousa, Paraiba State, and the filet industrial process was made in Jerico-Paraiba. It was used 2,700 fingerlings, produced by DNOCS – National Department of Workmanships Against Droughts, city of Caico, RN. The fingerlings were distributed in six tank-net of 4 m³, with density of 112.5 fishes/m³, with biometric averages of 62.8 g of weight and 13.72 cm of length. The experiment was conducted in 120 days, with frequently verification of the biometric development. It were verified the parameters of temperature, rainfall and limnology and the water samples were collected at 50 cm depth. The analyzed parameters kept up among the established limits for the growth of the species. At the end of the experiment was choosing ten fishes from each tank for zoo technical performance analyses. The experimental design was entirely randomized, in 3 x 2 factorial scheme with three sort of weight with skin and without skin in the fillet processing, with a total of 60 units shared in three weight classes (C1 = 500 to 600 g, C2 = 601 to 700g e C3 = 701 to 800 g). It was taken out two filets of each fish, one of them with skin and another one without skin and it observed that the weight with presence or not of skin caused variations in length and height of the analyzed filets. The filets with skin showed greater profit than the ones without skins (with skin = 36.18% and without skin = 34.28%), differing significantly amongst the values (P < 0.05). The filets from bigger fishes (C2 and C3) presented better results as for profit independently of skin presence or not. As referred to weight, the averages profit values of filets in C1, C2 and C3 had not differed significantly amongst themselves (C1 = 35.00%, C2 = 35.47% and C3 = 35.22%).