It can walk on land and breathe air.

It's life is very different from that of most fish.

A fish out of water.

Maybe, but they thrive here in Japan.

So what's made this upheaval worthwhile?

The answer lies in the mud.

As the tide retreats, it exposes mudflats.

Sunlight hits the rich silt and tiny plants and animals flourish.

There.

A ll food for a month, skipper.

But life on land is not without problems.

It's hard work to find a mate.

Jumping high above the mud will get you noticed with eyes perched on the top of their heads.

The mud skippers keep a lookout for both friend and foe, and males fight those who intrude on their territory.

They must also take care not to dry out in the sun.

Rolling in the jeweller's keeps the skin cool and moist.

For this smaller species, a better option is to retreat underground, so he digs himself a tunnel down into the mud.

His heap of spoil is an indication of the extent of his explorations.