Pattern of reproduction and recruitment in two sicyoniid shrimp species (Decapoda: Penaeoidea) from a tropical seagrass habitat

Abstract

The temporal pattern of breeding and recruitment was analyzed in populations of two species of penaeoid shrimp, Sicyonia parri (Burkenroad) and S. laevigata Stimpson, sampled for a 13-month period from seagrass meadows in a tropical locality, Puerto Rico. The reproductive condition of females was assessed by observing the degree of ovarian maturity and the presence or absence of sperm masses in the seminal receptacles. Adult females with “mature” ovaries were found in nearly all months of the year in both species, and a high proportion of adult females were inseminated during all months of the sampling period. Recruitment, estimated by changes in the proportion of individuals in juvenile size classes of monthly population samples, took place throughout the year and was highly correlated between the two species, with the highs and lows or recruiment indicating and episodic rather than a seasonal pattern. Comparisons of sicyoniid recruitment with that of caridean shrimps sampled from the same seagrass meadows suggest that different factors affected recruitment in the two groups. Comparisons of reproductive patterns of S. parri and S. laevigata with those of sicyoniid species from other latitudes suggest continuous reproduction, on the population level, in tropical sicyoniids and increasing restriction and seasonality of breeding periods in Sicyonia species from higher latitudes.