Size at first maturity of Adelomelon brasiliana near Mar del Plata, Argentina, was established analysing gonad tissue samples and the secondary sexual characters. Age was determined through growth marks. Gonad matures after development of secondary sexual characters.
Minimum shell length at sexual maturity is 107 mm in females and 102 mm in males. The shell length at which 50% of the animals are mature is 115.1 mm in females and 107.25 mm in males (approximatley 7 years of age). In males, penis matures before testis. All animals are mature beyond 125 mm in females and 115 mm in males, respectively (approximatley 8 years of age). The comparative late sexual maturation in this species makes the population quite sensitive to over-fishing.
