Desempenho de juvenis de tilápia do nilo (Oreochromis niloticus) e pacu (Piaractus mesopotamicus) em sistema de recirculação de água

Abstract

Growth performance was evaluated in juveline tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus) cultivated in recirculating water system. Pacu (6,49 ± 0,03 g) and tilapia juvelines (6,47 ± 0,02 g) were distributed in a completely randomized design with two treatments and ten replicates in a stocking density of 30 fish/ experimental unit. It was utilized a circulating water system with mechanical and biological filters and twenty experimental units, which were composed of lined masonry tanks with storage volume up to 1500 litre individual aeration system, water supply and disposal with renovation of 4L/min. The animals were fed three times a day until apparent satiety with experimental diets of 23,10% of digestible protein and 2931,28 Kcal/kg of digestible energy for pacu juveniles and 26,89% of digestible protein and3118,31Kcal/kg of digestible energy for juveniles Nile tilapia. The water physicochemical parameters were measured throughout the trial, such as pH, dissolved oxygen, total ammonia, nitrite and nitrate every two days, except for temperature, which was mesured daily. It is concluded that the average water physicochemical parameters have not affected the individuals performance and which were within the specified comfort interval for both species. Both in 40 than 70 days, Nile tilapia juveniles cultivated in recirculating system posts the best specified growth rates, feed conversion ratio, average weight, weight gain, condition factor and feed daily intake when compared to pacu juveniles. Recirculating aquaculture systems can be presented as an alternative for the production of tilapia and pacu juveniles.

Growth performance was evaluated in juveline tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus) cultivated in recirculating water system. Pacu (6,49 ± 0,03 g) and tilapia juvelines (6,47 ± 0,02 g) were distributed in a completely randomized design with two treatments and ten replicates in a stocking density of 30 fish/ experimental unit. It was utilized a circulating water system with mechanical and biological filters and twenty experimental units, which were composed of lined masonry tanks with storage volume up to 1500 litre individual aeration system, water supply and disposal with renovation of 4L/min. The animals were fed three times a day until apparent satiety with experimental diets of 23,10% of digestible protein and 2931,28 Kcal/kg of digestible energy for pacu juveniles and 26,89% of digestible protein and3118,31Kcal/kg of digestible energy for juveniles Nile tilapia. The water physicochemical parameters were measured throughout the trial, such as pH, dissolved oxygen, total ammonia, nitrite and nitrate every two days, except for temperature, which was mesured daily. It is concluded that the average water physicochemical parameters have not affected the individuals performance and which were within the specified comfort interval for both species. Both in 40 than 70 days, Nile tilapia juveniles cultivated in recirculating system posts the best specified growth rates, feed conversion ratio, average weight, weight gain, condition factor and feed daily intake when compared to pacu juveniles. Recirculating aquaculture systems can be presented as an alternative for the production of tilapia and pacu juveniles.