E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Homarus americanus H. Milne Edwards, 1837
American Lobster
Family: Nephropidae

© James Cosgrove  Email the photographer   (Photo ID #13392)

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Distribution of Homarus americanus in British Columbia
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Introduction


The American Lobster is a species of the Atlantic Coast of Canada and the United States. There have been several attempts at introductions of this species in the province (1950's) and reported individual releases of lobsters since then. Observations of adult lobsters have been reported by divers from Saanich Inlet (Cosgrove pers. comm.2011) and Indian Arm (Lamb and Hanby 2005). However, there are no reports of wild established populations in BC (Lamb pers. comm. 2011).

Read more about the biology of the Atlantic lobster.

Species Information

The American lobster is an introduced species in British Columbia, but has not naturalized, with no wild established populations reported. It ranges in length from 200–610 mm and weighs 0.45–4.1 kg (1-9 lbs). Specimens larger than this have been observed, however, with lengths of over 0.91 m (3 ft.), and weights of up to 20 kg (44 lbs.) or more.

This species is generally brown, brown green, or brown blue in colour, although lobsters that are mostly blue or yellow, or brown with yellow spots have been reported on the east coast. Lobsters have six pairs of legs, with the first pair modified as claws. The claws are different in appearance: one is used for crushing, and one is used for cutting--the bigger one is the crushing claw (Paille and Bourassa 2011).

Paille and Bourassa (2011) provide a detailed description and illustrations of lobster anatomy.

Biology


Behaviour: Lobsters are generally nocturnal and light sensitive. Adults stay close to the coast in summer, but migrate to deeper water in winter to avoid turbulence; young lobsters remain close to the coast in shelters (Paille and Bourassa 2011). Shelters are important and are used to avoid waves and currents, and to avoid predators—they are particularly important to young lobsters which are more vulnerable to predators than adults.

Reproduction: The American lobster mates in the summer just after females have molted. eggs are laid in the year following mating and remain attached to the female. A female can lay up a few thousand eggs to tens of thousands of eggs—the number is size-dependent. The eggs are carried for 9-12 months. Hatching is temperature driven, and ocurs between May and September. Tiny shrimp-like larvae only a few millimeters in length float to the water surface on hatching. By their third moult (post-larval stage), hatchlings resemble adult lobsters. Only on in ten thousand hatchlings make it to adulthood (Paille and Bourassa 2011).

Diet: While larval lobsters are omnivorous and will eat both zooplankton and phytoplankton, adults and juveniles are predatory and feed on shellfish, sea stars, sea urchins, marine worms and molluscs.

Predators: Young lobsters are preyed upon by fish such as cod, tench, flounder, sculpin, wolffish, ocean pout, monkfish, and dogfish, but the main predator of adult lobsters is man (Paille and Bourassa 2011). Lobsters moult in order to grow and after moulting, their carapace will remain soft for about a month, making them vulnerable to predators. To avoid predators during this time, they will moult in shelters.

Notes: Lobsters are reported to live for more than 50 years, although their maximum lifespan is not known (Paille and Bourassa 2011).

Habitat


Lobsters are generally found at depths of less than 50 m, but have been observed at depths of up to 700 meters (Paille and Bourassa 2011). Their preferred habitat is algae-covered rocky bottoms with many openings where they can hide (Paille and Bourassa 2011). However, they can also be found in gravel or sand bottoms, where they will dig a depression in the substrate (Paille and Bourassa 2011).

Distribution

Global Distribution

The native range of the American Lobster is the Atlantic Ocean along the North American coast, between North Carolina and Newfoundland and Labrador. However, it is generally associated with the colder waters around the Canadian Maritimes, Newfoundland and Labrador, Maine, Massachusetts, Rhode Island and New Hampshire. However, it has been introduced along the Pacific Coast of North America (California, Oregon, Washington, British Columbia.
Distribution in British Columbia

Many attempts at introducing this species in BC were made by Fisheries and Oceans Canada in the 1950's (Lamb and Hanby 2005). However, these all failed and no second generation lobsters were reported from these attempts. There are presently no records of American lobster breeding in BC.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
UnlistedUnlistedUnlistedUnlisted
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Photo Sources

Species References

Cosgrove, Jim. 2011. Personal communication. Email.

Lamb, Andy and Bernard Hanby. 2005. Marine Invertebrates of the Pacific Northwest. Harbour Publishing, Victoria.

Lamb, Andy. 2011. Personal communication. Email.

Paille, Nathalie and Luc Bourassa. 2011. American Lobster Fact Sheet. .St. Lawrence Global Observatory. Available online.

Van der Meeren, G. , Støttrup, J., Ulmestrand, M., Knutsen. J.A. 2006. Invasive Alien Species Fact Sheet – Homarus americanus. NOBANIS: Database of the North European and Baltic Network on Invasive Alien Species. Available Online.

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2019. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 21/11/2019 6:05:55 PM]
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