Evaluación del crecimiento, factor de conversión de alimento y calidad del agua del cultivo de trucha arco iris (Oncorhynchus mykiss) en un sistema cerrado

Abstract

The growth up of rainbow trout (Oncorhynchus mykiss) in a reuse reconditioning water system was carried out with the porpose to measure the growth rates, food convertion ratio and water quality. Ninety five trout with an average weight of 98.24 +- 18.89 grams and total length of 22.47 +- 0.95cm were used. These organisms were introduced in 5.6m3 circular tnaks, each one with a density of 3 ind/m3. The tanks flow of water maintained constant in 21 min-1 and the fishes were fed three times a day (3% of biomass) with a commercial diet containing 41.9 +- 0.13% preotein and 12.08 +- 0.12% lipids. Biomentrics parameters were measured every fouteen days and calculated the instantaneous growth rate (IGR), the specific growth rate (Gu), and Food Convertion Ratio (FCR). Also ammonia, toxic ammonia, nitrites, nitrates, dissolved oxygen and pH were registered along the experiment. The results shiwed after 39 days of culture, the trout increased to 140g in average weight and 26.4cm in average length. IGR was 0.02276, Gu of 11.67% day -1 and 1.4 of FCR. Temperature and pH (19.8 °C and 9.03 respectively) were constant along the experimet. Ammonia, nitrites and nitrates (0.01, 0.01 and 0.12 mg -1), and toxic ammonia presented higher variation, but not affected the survival and growth rates. The gained weight daily was of 3.6g day -1, that was a higher value compared with others results reported in related works, in spite of the higher average temperature registered along the experiment.