The clawed lobster Homarus gammarus is a common sight to divers diving in Ireland. They are blue in colour, with large claws, eight walking legs and a long body ending in a series of tail plates. Lobsters are most commonly found in rocky seabeds amongst boulders, and occur at depths down to 40M where they can find some shelter. Of their two large claws, one is a cutter and the other a crusher. The female abdomen is wider than the males. The Lobster is primarily nocturnally active, feeding on mussels and snails that it breaks open with the crushing claw. It will also feed on whatever carrion turns up.
The lobster spawns in late summer or autumn, directly following the moulting of the female. The male places the sticky mass of sperm near the opening of the female oviducts. The eggs are fertilised when they are discharged through the oviducts. Subsequently they are attached to the abdominal swimming legs of the female.