|The European green crab (Carcinus maenas) is also known as the shore crab.|
|Blue = native range, red = current invasive range, green = at risk|
Many of this species' characteristics makes it an incredibly infective invader. It tolerates a wide range of temperatures, salt levels, and types of habitat. It is an omnivore that will eat just about anything it gets its claws on, including known species from 158 genera at least. It is directly linked to falling numbers of several other species of crab as well as some mollusks. It is even linked to the collapse of the soft-shell crab industry in Nova Scotia and New England. $22 million in damages can be linked to this species in the United States alone. Overall, it has caused decreases in biomass and biodiversity of estuaries where it is found.
This species is currently on the list of 100 World's Worst Invasives at #18.
Images are from Wikimedia Commons under Creative Commons licenses: one, two.