Brycon hilarii produced in hapas: effects in allometric growth

Abstract

Abstract Biometric evaluations are essential to determine the growth characteristics related to the weight and length of fish. This study aimed to determine the growth patterns of juvenile piraputangas (Brycon hilarii) produced in hapas within an excavated pond. The piraputangas were anesthetized and micro-chipped and their biometric characteristics were measured. Subsequently, the fish were distributed in six hapas of eight m3 at the density of 20 fish/hapa, totaling 120 animals. During the experimental period six months, the fish were fed twice (5% of the biomass) a day. Every 30 days, all fish were sampled to measure the biometric characteristics of body weight (g); standard length; total length; head height; head length; body height and body width (cm). The calculations of the weight ratio with the biometric characteristics were determined using allometric equation and estimated by linear regression according to the equation log Y = log a + b log X. All tested relationships were significant by the Student t-test (p < 0.05). Allometric growth was positive for: weight x total length; standard weight x length; weight x head height; weight x head length and weight x body height. The relative condition factor of piraputangas observed in this study was 1.00. The study provided information on the allometric parameters of juvenile Brycon hilarii produced in hapas, and the relative condition factor indicated good growth conditions for piraputangas with positive allometric growth.