Meeting Abstract
Studying invasive species is important because they can have far reaching impacts on ecosystems. Grass shrimp are an important ecological species in food web dynamics in estuarine systems. Local fish species, crabs, and wading birds all feed on these small shrimp. Palaemon macrodactylus, an invasive species of grass shrimp was examined to determine if there were any differences in reproductive output when compared to three native species of grass shrimp in New Jersey waters. A total of 88 shrimp were collected from seven sites from April 2018 to September 2018. Larger body sizes of females has been correlated to larger production of eggs. The number of gravid females collected from each of the seven sites of each species was recorded. The size of each of the gravid females were recorded. Eggs were examined to confirm that they were viable eggs. The distributions of morphological size for Palaemonetes pugio, Palaemonetes vulgaris and Palaemon intermedius were not significantly different from being normal (p > 0.05). While the distribution for Palaemon macrodactylus was significantly different from normal (p = 0.001). The Shapiro-Wilks test was used to help with the normality of the size distribution for each species, the differences between the means of sizes for all species, P. pugio, P. vulgaris, P. intermedius, and P. macrodactylus was not statistically significant, Welch’s F(3, 29.350) = 1.740, p = 0.181. Additional analysis is being conducted looking at egg mass, individual egg count and morphological size ratios. This study has confirmed that the invasive species has a larger body size overall compared to the native species and has a potential to outcompete the native species in reproduction.
