Reproductive cycle and gonadal development of Leukoma pectorina (Bivalvia: Veneridae) on the northern coast of Brazil

The reproductive cycle and gonadal development of the “sarnambi”, Leukoma pectorina (Lamarck, 1818), was studied between June 2008 and July 2009 on the coast of Pará (Brazil). Histological analyses were performed on 633 indi-viduals and, through microscopic observations, sexing and characterization of gonadal development were carried out. Sub-sequently, based on histological images, the diameters of oocytes were counted and measured to determine the reproductive period. The population showed a sex ratio of 1:1.3 (female: male). Females were significantly more frequent in small sizes of 2–7 mm, while larger individuals predominantly consisted of males. The size of the first maturation occurred at 11.80 mm for males and 14.40 mm for females. The population exhibited continuous spawning, with abundance of oocytes correlating with salinity. It is concluded that there are five stages of gonadal development and gonochorism, a typical strategy of tropical bivalves, supporting global hypotheses. For the preservation of the species, it is recommended that these organisms be cap-tured with shell lengths above 15 mm. In addition, further research on the parasite found in this study is necessary, as it could compromise the population’s fecundity rate.