Population structure of the shrimp Palaemon pandaliformis (Stimpson, 1871) (Caridea: Palaemonidae) in the river Rio Itapemirim, in Southeastern Brazil

Abstract The present study analyzes the population structure of Palaemon pandaliformis, based on sex ratio, the frequency distribution in defined size classes and the reproductive biology of samples captured in seasonal collections (winter 2011 to autumn 2012) with sieves under marginal vegetation. A total of 1,043 specimens were obtained, 222 juveniles, 465 males and 356 females, being that of this total of females, 58.42% were in the ovigerous condition. The average size of the carapace for both sexes varied between 4 and 6 mm (p> 0.05) only the ovigerous females had higher averages (p