PHENOTYPIC CHARACTERIZATION OF FOUR BREEDING STOCK RAINBOW TROUT POPULATIONS (ONCORHYNCHUS MYKISS) FROM FIAD TROUT FARM, BISTRIŢA-NĂSĂUD COUNTY

D. Cocan, Vioara Mireşan, R. Constantinescu, Camelia Răducu, Iulia Feştilă

Abstract
Statistical data of last years reveal a significant fish consumption increase by human, but also of other aquatic organisms, which are over 400 species, from which fishes represent about 200 species [10]. Because natural resources are more and more reduced, the aquaculture has an ascendant trend and inside it the salmoniculture detains a forehead place. In this context, it is necessary to be permanently perfected salmonid breeding methods and technologies, following to obtain some production qualitatively as great and appropriate as possible, by maximum exploitation of the biological potential of culture material. Inside this experiment, the authors determined the body weight and main morpho-physiological indices on a number of 80 rainbow trout (Oncorhynchus mykiss) breeding stock individuals, taking in study randomly 20 individuals (10 males and 10 females) from the existent four breeding stock populations inside Fiad trout farm, Bistriţa-Năsăud County. Description of these body weight indices and those of body frame ones, by age categories, will permit inside this trout farm the optimal age, body weight and body frame determination that breeding stock must have in view to obtain some viable and valuable offspring, both qualitatively and also quantitatively. Finally, the obtained data were statistically processed and interpreted.

Key words: rainbow trout, morphological indices, body weight, reproduction