Thousands of crabs gather on Falmouth beach in spectacular natural phenomenon

Thousands of spider crabs have been spotted in a mass gathering off the coast of Cornwall, in what has been described as a “spectacular natural phenomenon”.

The annual spectacle happens when crabs rally together to protect themselves while moulting - the process of shedding a shell and developing a new one.

“Looking down at the mass of crabs scuttling on the seabed was a truly incredible experience,” Matt Slater, from Cornwall Wildlife Trust said of the phenomenon, filmed off a beach in Falmouth.