Population dynamics and reproductive strategy of Scolelepis goodbodyi (Polychaeta: Spionidae) in a subtropical atlantic beach

the population dynamics and reproductive strategy of the polychaete scolelepis goodbodyi (jones, 1962), were investigated between june 2009 and may 2010 at manguinhos beach, southeastern, brazil. a total of 9,242 individuals were collected. the density did not differ significantly from one month to another. the estimated values of the growth, recruitment, and mortality rates were studied using the width of the third setiger and the growth curves for the populations were adjusted by the bhattacharya method (l'= 1.23, k = 1.2, mortality = 0.73). two annual cohorts were identified in the period. significant differences between males and females were observed in the population (x2 = 71.6, p < 0.01) and between sexually defined and sexually indeterminate individuals (x2 = 158.4, p < 0.01). five stages of gonadal development were identified. the coexistence of recruits and mature individuals throughout the study period suggests that this population presented continuous reproduction.