Animal · Indonesia, Malaysia, Thailand
Mudskipper
Periophthalmus — the name this animal has in the language scientists everywhere share.
A mudskipper is a fish that spends most of its life out of the water, walking over the mud on its front fins and staring with goggle eyes. It lives on tropical mangrove shores where the sea comes and goes twice a day.
Picture credit: Rick888chen (CC BY-SA 4.0) · Thomas Brown (CC BY 2.0) · Wikimedia Commons
Where does the mudskipper live?
Home: Muddy mangrove shores between the tides.
In the wild it lives in these countries: Indonesia, Malaysia, Thailand, the Philippines, India, Australia.
The short profile
Fully grown: most are 10 to 20 cm long. It weighs about 0.05 kilograms. On the menu: meat.
The story behind it
When the tide goes out, the mudflat fills with fish that are not swimming. A mudskipper props itself up on two muscular front fins and shuffles, hops and skips across the wet mud, sometimes leaping half a metre in one go. It can do this because it carries its own water supply: it takes a mouthful of water into swollen gill chambers before it leaves the sea, and it also takes in oxygen straight through its damp skin and the lining of its mouth. Its eyes sit on top of its head like two small periscopes, so it can watch for danger in every direction, and it rolls them down into a cup of water now and then to keep them wet. Males dig deep burrows in the mud and the eggs are laid in an air pocket inside. To defend a patch of mud, a male raises the fin on his back and jumps into the air. There are about twenty-five kinds of mudskipper, living from West Africa to northern Australia.
Find it on the globe
Mudskipper is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
Can a mudskipper drown?
It still needs water, just not to breathe in the usual way. If its skin dries out it is in real trouble, so it rolls in wet mud and goes back to a puddle again and again.
Why are its eyes on top of its head?
From up there it can watch the whole flat at once, and also see above the water while its body stays in a puddle. Each eye moves on its own, so it can look two ways at the same time.
What is inside a mudskipper's burrow?
The tunnel runs down into the mud and often ends in a chamber holding a trapped bubble of air. The eggs stick to the ceiling of that chamber, where they can take in oxygen until they hatch.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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