Thousands of spider crabs spotted in Cornwall

Thousands of spider crabs have been discovered in Cornwall this summer.

Spider crabs are known for their long, spiny legs and claws spanning up to 1m (3ft).

They gather together for protection when they shed their shells and wait for new ones to harden.

Gatherings usually take place in warmer water. Marine biologists say there has been an increase in these mass events the UK because of climate change.

Cornwall Wildlife Trust has encouraged members of the public to record any sightings but says the crabs are not dangerous.