Specieswatch: cuttlefish – clever, colourful and now at risk

Specieswatch: cuttlefish – clever, colourful and now at risk

Most of us are familiar with the remains of cuttlefish, Sepia officinalis, large chalky internal shells that are washed up on beaches and sold in pet shops as a source of calcium for birds.

This relative of the squid and octopus thrives in the seas around Britain and is caught in large numbers for our continental neighbours who regard them as a culinary delicacy. Europeans also use their ink as a colouring agent in food, ink and paint.

Owing to over-exploitation, cuttlefish have just been declared an endangered species along the south coast. Next month they will be coming into shallow water to breed and lay their rubbery black eggs, known as sea grapes, on seaweed and sea grass.

They are remarkable partly because they can change colour at will to match their background but also use this talent in dazzling courtship displays. More recently, scientists have discovered that they are both intelligent and have good memories.

While cuttlefish eat lots of things, including crabs, their favourite food is shrimps. In a series of experiments using captive specimens, scientists discovered that they could remember routines and be patient. For example, even though they were hungry and crabs were available to eat, they would abstain in order to leave room to eat shrimps later.

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