Primary food sources:
* Seaweed and algae: This forms a large part of their diet, especially for smaller crabs.
* Dead animals: They scavenge on carcasses of fish, worms, and other marine creatures.
* Worms: They actively hunt and dig for worms in the seabed.
* Mollusks: They crack open shells of mussels, clams, and oysters using their strong claws.
* Small crustaceans: They eat barnacles, shrimps, and other small crabs.
Other items they might eat:
* Fish: They may occasionally catch small fish.
* Plankton: They filter plankton from the water, especially when they are younger.
* Debris: They eat anything they can find, including bits of seaweed, shells, and other organic matter.
Specific examples of crab species and their diets:
* Brown Crab (Cancer pagurus): This is a common edible crab, their diet is mainly shellfish, worms, and small fish.
* Common Shore Crab (Carcinus maenas): This is a more generalist, feeding on a wide range of food including worms, shellfish, seaweed, and dead animals.
* Velvet Swimming Crab (Necora puber): This crab is an active predator, eating mainly fish and small crustaceans.
Ultimately, the exact diet of a British crab depends on its species, age, location, and the availability of food.