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Filmed 20 kg giant jellyfish off the coast of Cornwall

June 29, 2014 Last updated at 15:34 BST clock

A huge cannon jellyfish swim spotted in an estuary near St Mawes Cornwall.

Cornwall Wildlife Trust Marine sensitizer Matt Slater and his dog swam to the jellyfish to capture these images.

Medusa is said to weigh up to 20 kg and measure about one meter in diameter.