As females of tambaqui (Colossoma macropomum) are heavier than males at harvest, farming all-female populations would be more profitable. Unraveling the genetic and physiological mechanisms involved in sex determination and sex differentiation is then a fundamental objective in order to achieve sex control in this species. Therefore, we produced and assembled individual transcriptome libraries of juveniles sampled just prior to the gonadal sex differentiation in order to identify genes putatively related to testicular or ovarian differentiation in tambaqui
