Fecundity of Palaemon carteri (Gordon, 1935) (Crustacea: Decapoda: Palaemonidae) from the Eastern Amazon, Brazil

Palaemon carteri is one of the most common palaemonid shrimps in the Amazon region. The objective was to analyze the fecundity of P. carteri from the Eastern Amazon. The specimens derive from 11 streams, which were sampled in 2011. Using a stereomicroscope and an ocular micrometer, the total length, cephalothorax length, rostrum length, and abdomen length of ovigerous females were obtained. The eggs were counted, and their major and minor axes were measured. Based on eye pigmentation in the eggs, two groups of females were sorted according to the development stage of the embryos. A total of 65 ovigerous females were analyzed, with mean total length of 26.11 +/- 1.36 mm (range: 23.00 to 29.16). Regarding body size, there was no difference between the two groups of females. The mean egg number was 18 (range: 4 to 29). Females with eggs in the initial development stage had a higher number of eggs (mean: 20 +/- 3.8) than the ones in a more advanced stage (mean: 16 +/- 5.1). On the other hand, the latter presented a higher mean volume (0.91 +/- 0.27 mm(3)). Palaemon carteri has low fecundity compared with other palaemonid species, and egg loss during incubation seems to favor the survival chances of the remaining embryos.