The sea slug's ability to swim freely in the midwaters is a departure from the norm for nudibranchs. Bathydevius caudactylus flexes its body up and down to swim or drifts motionless with the currents.

Experts said the find at Wembury, near Plymouth, was "amazing" A nature enthusiast and her father have made a colourful discovery of a sea slug usually found in the Mediterranean in a rock pool in ...

More than two decades after spotting a mysterious, gelatinous, bioluminescent creature swimming in the deep sea, California researchers have announced that it is a new species of sea slug.