Fecundity of Palaemon northropi (Rankin, 1898) (Caridea: Palaemonidae) in southern Bahia, Brazil

Abstract

Abstract Knowledge of the fecundity of a species may facilitate the estimation of its reproductive potential and provide information regarding future stock size. Previous studies have shown variation in some reproductive parameters of Palaemon northropi, and we evaluated a new population to investigate the consistency and drivers of this variation. The objective of this study was to evaluate some reproductive characteristics of the shrimp P. northropi, from a population sampled on Me Ache Beach, in the municipality of Ilhéus, Bahia, Brazil. After sampling, carapace lengths were measured and embryonated eggs were removed, counted, weighed, and classified according to their stage of development. A total of 108 females were collected. The mean size of individuals was 6.2 ± 0.58 mm and the mean number of embryos per female was 234 ± 91 in developmental stage I and 195 ± 77 in developmental stage II. We found that the fecundity of P. northropi was influenced by the length of the carapace and the stage of embryo development, which we considered to indicate embryonated egg loss during incubation. The lack of correlation between reproductive investment and female size, suggests a stabilized investment pattern, likely reflecting an evolutionary trade-off between maximizing fecundity and the physical and energetic constraints imposed by the carapace volume and female survival. Ultimately, the consistent proportional allocation of energy underscores the species' resilience, showing how local selective pressures can mold reproductive traits to mitigate brood mortality in the intertidal zone.