| Title: | Gonadal steroids and energy availability during ovarian maturation stages of the Amazonian pirarucu Arapaima gigas (Teleostei: Osteoglossidae) in the wild |
| Author(s): | Amaral JS; Venturieri RL; Moreira RG; |
| Address: | "Laboratorio de Metabolismo e Reproducao de Organismos Aquaticos, Departamento de Fisiologia, Instituto de Biociencias, Universidade de Sao Paulo, Brazil. Original Amazon, Sao Paulo, SP, Brazil. Laboratorio de Metabolismo e Reproducao de Organismos Aquaticos, Departamento de Fisiologia, Instituto de Biociencias, Universidade de Sao Paulo, Brazil. Electronic address: renatagm@ib.usp.br" |
| Journal Title: | Comp Biochem Physiol A Mol Integr Physiol |
| DOI: | 10.1016/j.cbpa.2019.01.008 |
| ISSN/ISBN: | 1531-4332 (Electronic) 1095-6433 (Linking) |
| 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 (E(2)) 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 reproductive stages is similar to that found in most teleosts, but plasma 11KT levels peaked at the mature stage, suggesting an important role of this androgen in female ovulation. The 11KT/E(2) method was 100% efficient when sexing juveniles and adults at the beginning of their reproductive cycle and can successfully be applied to identify the sexual gender of animals. The steroid profile of the cephalic liquid suggests a possible role of this fluid as a pheromone, due to the high level of 17alpha-hydroxyprogesterone at the final stages of the reproductive cycle" |
| Keywords: | Animals *Energy Metabolism Female Fishes/*metabolism Gonadal Steroid Hormones/blood/*metabolism Lipid Metabolism Ovary/growth & development/*metabolism/physiology Reproduction Cephalic liquid Lipids Protein; |
| Notes: | "MedlineAmaral, Juliane S Venturieri, Rossana Leite Moreira, Renata Guimaraes eng Research Support, Non-U.S. Gov't 2019/01/21 Comp Biochem Physiol A Mol Integr Physiol. 2019 Apr; 230:106-114. doi: 10.1016/j.cbpa.2019.01.008. Epub 2019 Jan 17" |
