Growth curve by Gompertz nonlinear regression model in female and males in tambaqui (Colossoma macropomum)

Abstract

Was evaluated the pattern of growth among females and males of tambaqui by Gompertz nonlinear regression model. Five traits of economic importance were measured on 145 animals during the three years, totaling 981 morphometric data analyzed. Different curves were adjusted between males and females for body weight, height and head length and only one curve was adjusted to the width and body length. The asymptotic weight (a) and relative growth rate to maturity (k) were different between sexes in animals with ± 5 kg; slaughter weight practiced by a specific niche market, very profitable. However, there was no difference between males and females up to ± 2 kg; slaughter weight established to supply the bigger consumer market. Females showed weight greater than males (± 280 g), which are more suitable for fish farming purposes defined for the niche market to larger animals. In general, males had lower maximum growth rate (8.66 g / day) than females (9.34 g / day), however, reached faster than females, 476 and 486 days growth rate, respectively. The height and length body are the traits that contributed most to the weight at 516 days (P <0.001).

Weight gain and morphometric growth of genetically improved tambaqui (Colossoma macropomum)

“…Breeding program families registered gains over 29.0% when compared to those in current assay, and in less time, emphasizing the importance of breeding program for tambaqui. Mello et al (2015) reported higher growth rates than those given by these authors and rates close to those in current assay, featuring growth rates at 8.66 g/day and 9.34 g/day, respectively for male and female tambaquis. …”

“…This feature is undesirable since it provides smaller carcass yield (REIDEL et al, 2004;BOMBARDELLI et al, 2005;ADAMES et al, 2014). In fact, Mello et al (2015) observed that there were differences in the growth pattern of the size of the head in tambaquis, or rather, females had a higher growth rate (albeit slow) when compared to males. However, the authors continued their assay till the sexual maturity of the tambaquis (three years), whereas fish in current assay were assessed in less than half that time (481 days) and without sexual differentiation, which impairs any comparison.…”

“…It is an autochthonous fish of the Amazon basin, widely distributed in the tropical regions of South America and Central Amazon (ARAÚJO-LIMA; GOULDING, 1997), considered the second largest scale fish of the Solimões and Amazon rivers. It may reach up to 100 cm long and weigh 30 kg in its natural environment (NAKATANI et al, 2001). …”

“…The first selected generation of tambaqui for weight gain (G1) was obtained at the end of 2011 and early 2012, with positive effects on growth pattern and weight gain (OLIVEIRA et al, 2012;MELLO et al, 2015).…”

Morphological and morphometric analysis of skeletal muscle between male and female young adult Colossoma macropomum (Characiformes: Serrasalmidae)

“…Indeed, on the premise that females mature later than males, the nutrients from diet would be directed to muscle growth and weight gain, leading females to reach a larger size. However, this is not valid for the tambaqui once the commercial slaughter takes place before the fish reach sexual maturity (Mello et al, 2015).…”