Physiological effects of limb loss on the Asian Shore Crab, Hemigrapsus sanguineus.
Invasive species pose a considerable threat to biodiversity and the functioning of the ecosystem. Hemigrapsus sanguineus (Asian Shore Crab) has outnumbered native crabs on the northeast coast of North America since shortly after its introduction in the late 1980s. Asian Shore Crabs occur in high densities along much of the Atlantic coast from Maine to North Carolina. Our research focused on the relationship between limb loss and energy use and storage in both male and female Asian Shore Crabs as a means of understanding their ability to reach high population densities. We sampled 154 crabs of both sexes from Odiorne Point State Park in Rye, NH. We then dissected the individual specimens and measured limb loss and the mass of the hepatopancreas (an energy storage organ) and gonads. Our findings reveal that limb loss has similarly limited impacts on male and female crabs in terms of both energy storage and reproductive effort. We conclude that despite a high frequency of injury, the energetics of Asian Shore Crabs were largely unaffected, and that this may be one reason why this species has been able to achieve sustained high densities throughout much of its invaded range.