Species encyclopedia

Common Lobster

Homarus gammarus


The common lobster, recognizable for its royal blue colouring when alive, can be found on rocky seabeds 20 to 100 m below the surface.

Hidden under cover during the day, it comes out at night to search for food – molluscs, worms, crustaceans and dead animals – which it catches using its two claws of different shapes and sizes. The large one is used for crushing and the other, more delicate, one has saw-like teeth that allow it to cut up its food.

It uses its two pairs of antennae to locate its prey. One is smaller and senses smell, while the larger one is used for touch.

The lobster is a solitary creature that can only stand the presence of its fellow creatures during the reproductive period. Mating takes place after the female sheds her shell. She then stores up the sperm, using it to fertilize her eggs for the next two years.


Ovulation occurs between July and December. The female carries her 5,000 to 50,000 eggs under her belly for 7 to 10 months. On hatching, the larvae let themselves be carried away by the current and then, 2 or 3 months later, swim down to the ocean floor to find shelter. Only two or three of the original clutch will reach adulthood.

Like all crustaceans, as lobsters grow, they shed their too-small shells to make another, bigger one, allowing them to grow an additional 20%. In the first year, lobsters cast off about 10 shells, then three or four the next year, and just once or twice in their third year. After that, the process becomes increasingly infrequent.

An average size for a lobster is 25 to 50 cm, although they can reach up to 60 cm with a weight of 8 kg.

The natural life expectancy of a lobster is 15 to 20 years, but it is rare to find any that old, due to the pressure placed on the species by fishing.
Some individual lobsters have even been kept in aquariums for upwards of 50 years.

Atlantic Ocean


Species encyclopedia

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