COMPARISON AND INTERACTION GENOTIPE-ENVIRONMENT OF THE PRODUCTIVE PERFORMANCE IN THREE GENETIC LINES OF TILAPIA Oreochromis sp.]

Abstract

Tilapia is the second most widely cultivated species in the international scope, due to their fast growing and breeding capacity in captivity. Its biggest problem is the unpredictability of the productive performance of varieties in different environments and management types. For this reason, the productive performance of three lines: Oreochromis niloticus (N), red Oreochromis mossambicus (M) and Rocky Mountain (R), cultured in five sites in two environments (Presses: Miguel de la Madrid and Miguel Aleman in the State of Oaxaca, Mexico) was compared. Cages with dimensions between 18 and 48 m3 with stocking density of 7 to 28 fish m-3 were used. Feeding varied depending on the producers (1 to 3 portions a day/cage (300 to 1200 g of feed). Total length (TL), weight (P), survival (SUP) and fillet yield (RF) were evaluated in each genetic line. Results from physicochemical parameters of water, environments of culture and production efficiency of the strains indicated no significant differences, except for weight gain (g) between sites of culture. However, it was considered that the differences were mainly due to handling during the culture, rather than the genetic line. Genetic lines showed similar performance (Tilapia R: LT 16.5 ± 3.1 cm, P 99.0± 46.6 g, 28 % RF, SUP 91.6 %. Tilapia N: LT 16.7 ± 3.7 cm, P 98.2 ± 40.9, RF 23 % SUP 86 %. Tilapia M: LT 15.4 ± 4.6 cm, P 100.1 ± 112.5 g, 30 % RF, SUP 91.6 %). Under the conditions evaluated, type of management could influence the efficiency of the culture more than the genetic line.