Morphometric Analysis of Asian Shore Crab hemigraspus sanguineus

Abstract

Hemigrapsus sanguineus (Asian Shore Crab) is an invasive species that arrived from the Western Pacific in the late 1980s. Hemigraspus sanguineus dominated the Northeast after it arrived and decimated native populations of crab. There are many differences between male and female individuals. A morphometrical analysis was done to determine if certain characteristics grow isometrically or allometrically compared to the rest of the body. The following characteristic features were analyzed and compared: carapace width and crab biomass, carapace width and carapace length, carapace width and propodus height, crab biomass and propodus mass, carapace width and total egg mass, and crab biomass and total egg mass. Crabs are known to show sexual dimorphism. Female individuals had a larger carapace width while males had a larger right propodus. A larger carapace width for females will allow them to brood more eggs.