Meeting Abstract
The green crab, Carcinus maenas, is a globally invasive species native to Europe. It was introduced to the Eastern US in the early 1800’s and then to Nova Scotia and Prince Edward Island in the 1980’s. This led to genetically different populations of green crabs on the east coast of North America. Our project investigates population specific differences in stress physiology, behavior, and habitat destruction. Crabs were collected in Maine (ME), Nova Scotia (NS), and Newfoundland (NF) and incubated at 3, 8, and 16ºC, and at 12, 34, and 40 ppt for 48 hours. Gene and protein expression of HSP70, AMPK, and Na+-K+-2Cl–-cotransporter was measured in heart, chelae, gill, and hepatopancreas tissue. We also measured aggression, righting response, and treadmill running endurance. To assess damage to seagrass habitat from the animals, crabs were placed in a 5 m diameter mesocosm that contained 3 different densities of Zostera marina. Location of the crabs within the tank was quantified over 3 days by daily observations and Z. marina damage was evaluated for frayed blades, and uprooted plants. First results show that crabs from NF spent more time above the sediment than those from ME, which can lead to more seagrass disruption, while above the sediment the crabs from ME are more destructive to Z. marina. Crabs from NS were more aggressive than ME and NF populations at all temperatures. At 3ºC NS crabs were the least active on the treadmill. The NF crabs were consistently more active on the treadmill at 3ºC. Ongoing analyses of the tissue samples will show whether the observed behavioral differences are mirrored in cellular and molecular stress parameters. A mechanistic understanding of the population-specific tolerance and behavior is crucial for predicting potential future invasions of this species.
