Produção de guppys (Poecilia reticulata) em sistemas de cultivo com bioflocos

Abstract

In order to assess the feasibility of guppy (Poecilia reticulata) production in system with bioflocs, two experiments were developed in Aquariofilia Laboratory of Federal University of Pampa, Uruguaiana, RS. The experiments were conducted in a completely randomized design and the results were submitted to analysis of variance ANOVA and the comparison of means by Tukey test (5%). The first study aimed to evaluate the performance of juvenile guppys (initial total length of 18.06 ± 0.30 mm and initial weight 0.056 ± 0.003 g), produced in biofloc system with different feed rates, comparing to a production system in clear water. Four treatments were evaluated with four replicates: clear water (control) system with feed supply 3% of body weight (CWS), biofloc technology system without the supply of feed (BFT0), biofloc technology system with feed supply 1.5% of body weight (BFT1.5) and biofloc technology system with feed supply 3% of body weight (BFT3). Water quality parameters were monitored weekly. The results showed that biofloc treatments showed better control of water ammonia levels. At the end of experiment the animals CWS, BFT and BFT1.5 showed no significant differences, for TL, SL, weight and SGR. However, all treatments were lower than BFT3 treatment in all three performance variables. In contrast, the FCR had no significant difference between the BFT1.5 and BFT3 treatments, being CWS the highest treatment. Survival was superior in the treatments with supply of feed. The second study aimed to evaluate the performance of juvenile guppys (initial total length 12.10 ± 0.13 mm and initial weight 0.015 ± 0.000 g) submitted to food restriction and refeeding cycles in biofloc system. Three treatments were evaluated, with six replications: clear water (control) system with daily food (CWS), biofloc technology system with food for five days followed by two days of food restriction (BFTR) and biofloc technology system with daily food (BFT). The animals were maintained until they enter the reproductive period and water quality parameters were measured weekly. The results demonstrate that the BFT cultivation systems with and without feed restriction showed better control of nitrite levels compared to the system in clear water. Animals produced in BFT systems with and without food restriction reached the reproductive period at half time required for animals produced in clear water system, and showed better growth performance (TL, SL, Weight, FCR and SGW). These results suggest that BFT system can be employed in guppys farming, serving as food source for organisms grown, improving growth performance and water quality parameters.