American Lobster
(Homarus americanus)

Description: Familiar from supermarkets and seafood restaurants, this species can immediately be distinguished from the native Californian spiny lobster due to its large claws. One pincer is enlarged and thickened (used for crushing) while the other is finer (used for tearing). Live lobster colors can be a mottled reddish brown, white or blue; they turn bright red only after cooking. A typical adult lobster measures between 45 to 135 mm in length.

Habitat: They can be found in the subtidal zone on rock, sand, mud or hiding amongst the seaweed. Females are thought to enter warm, shallow waters such as bays to accelerate egg development. American lobsters come out of their dens at night to hunt.

Origin: East Coast of North America.

Invaded Areas: A few individuals sighted on California shores.

Concerns: The American lobster is an opportunistic feeder with a broad diet. Because of its adeptness at crushing shelled prey, an invasion of American lobsters could threaten native mollusks and compete with other species that share the same food sources. They are the basis of a commercially lucrative fishery on the East Coast, and individuals might be tempted to intentionally introduce lobsters to the West Coast. In 1874, four egg-bearing females were placed in San Francisco Bay. Four other shipments were placed in Monterey Bay and several lobsters were caught later by Monterey fisherman. Lobsters are also used for research at marine labs, and have been sighted in adjacent waters. Despite these sporadic introductions, no lobster populations have established in California.