The moon jelly is the most common jellyfish in UK seas, often washing up on our beaches. No need to worry though - it doesn't sting humans.

The fearsome common backswimmer hunts insects, tadpoles and fish. It uses its oar-like legs to swim upside-down under the water's surface where unsuspecting prey can be found.

Did you know that there are coral reefs in the UK? UK seas are home to some amazing cold-water corals that form reefs on the seabed over 400m deep.

The stone loach is notoriously hard to spot - not only is it mostly nocturnal, it is also well camouflaged and can partially bury itself in the riverbed. It uses its whisker-like barbels to find…

This little fish is found in rockpools during the summer months and has a clever adaptation that stops it being swept away by strong waves - their pelvic fins are fused to form a sucker that it…

An underwater predator, the Saucer bug uses its front pincer-like legs to catch its prey. It can be found at the bottom of muddy, weedy ponds; but handle with care - it can inflict a painful bite…

One of the most colourful fish in UK seas, the cuckoo wrasse looks like it belongs in the tropics. Don't be fooled though, it's very much a native species.

Sugar kelp is the crinkly belt like kelp that can often be found in deep rockpools on the lower shore or washed up on the beach after rough seas.