Common lobster  (Homarus gammarus)

Common and widespread (2).

The common lobster is a very large and commercially important species (3). The upper surface is dark blue in colour with yellowish spots; the underside is more yellowish (3). The long abdomen terminates in a broad tail fan, and the first pair of walking legs, which are held forwards, are tipped with very large, formidable pincers. The pincers differ in size; one is used to cut prey, the other for crushing (4).

This lobster has a wide distribution around the coasts of Europe (4), and is found around all British coasts (2).

Lives in holes and tunnels on rocky substrata (2) from the lower shore to the sublittoral zone (4).

The common lobster is a scavenger, and uses its pincers to manipulate food items (4).

The sexes are separate, spawning occurs once a year in summer, and after mating, the female carries the eggs on her walking legs for around 9 months. The larvae are planktonic, and settle at around 3 weeks after hatching (4). Young lobsters are not often found, and very little is known of the behaviour of this stage, but it is believed that they live in coarse sediments and fine mud, where they construct burrows (4). Sexual maturity is reached at around 6 years of age; common lobsters are long-lived, and may live to over 15 years. Unfortunately, very few specimens reach such a ripe age, due to the pressures of intense fishing (4).

Numbers of the common lobster have been greatly depleted through overfishing; it is fished commercially using baited 'lobster pots'. As the lifecycle is not fully known, it is extremely difficult to sustainably manage the fishing of this species (5).

Specific conservation action has not been targeted at this species.

For more on this species see the Marine Life Information Network (MarLIN) species account, available from:
http://www.marlin.ac.uk/species/Homarusgammarus.htm

• Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree. In crustacea (e.g. crabs) the limbs attach to the abdomen; in insects the limbs are attached to the thorax (the part of the body nearest to the head) and not the abdomen. In vertebrates the abdomen is the part of the body that contains the internal organs (except the heart and lungs).
• Larvae: stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
• Planktonic: aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).
• Sublittoral: a marine zone between the littoral zone (the shallow zone where light reaches the bed, subject to submersion and exposure by tides) and depths of around 200m.

1. National Biodiversity Network Species Dictionary (January, 2003)
   http://www.nhm.ac.uk/nbn/
2. Wilson, E. 2002. Homarus gammarus. Common lobster. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. (November, 2002)
   http://www.marlin.ac.uk/species/Homarusgammarus.htm
3. Burnie, D. (2001) Animal.Dorling Kindersley, London.
4. Fish, J.D. and Fish, S. (1996) A student's guide to the seashore. Second Edition.Cambridge University Press, Cambridge.
5. Buczacki, S. (2002) Fauna Britannica.Hamlyn, London.