Gonadal steroids and energy availability during ovarian maturation stages of the Amazonian pirarucu Arapaima gigas (Teleostei: Osteoglossidae) in the wild.

Gonadal steroids and energy availability during ovarian maturation stages of the Amazonian pirarucu Arapaima gigas (Teleostei: Osteoglossidae) in the wild. Comp Biochem Physiol A Mol Integr Physiol. 2019 Jan 17;: Authors: Amaral JS, Venturieri RL, Moreira RG Abstract The Amazonian pirarucu, Arapaima gigas, belongs to a phylogenetically basal group of teleosts (family Osteoglossidae). The commercial importance and the overexploited status of natural stocks of A. gigas brought the interest to rear it in the Amazon region, but rearing techniques are not fully understood to obtain reproduction success. Gonadal steroids (plasma and cephalic liquid), lipids and proteins (muscles, liver and ovary) of wild A. gigas females were analyzed during one year on Mexiana Island (Amazon Basin, Brazil) and ovarian maturation stages were described. The sexual gender determination method based on 11-ketostestosterone (11KT) and estradiol (E2) ratio was applied to check if the value is in agreement of the sex previously determined by direct observation. Adult females were classified into four reproductive stages according to ovary development stage: previtellogenic, maturation, mature, and regression/spawning. Immature females were also analyzed. All mature females were sampled during the rainy season. Lipids stored in the ventrecha (belly) are a possible source of this substrate for the developing ovary. Plasma steroid profile throughout A. gigas female...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - Category: Physiology Authors: Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research