On the muddy shores of Indonesia’s mangrove forests, fish can sometimes be seen doing something unbelievable — climbing rocks, crawling through roots, even leaping across puddles. These creatures are mudskippers, amphibious fish that spend more time out of water than in it.
Mudskippers live in coastal swamps where tides rise and fall dramatically. To survive, they’ve evolved an extraordinary set of adaptations that let them breathe and move on land. Their gill chambers trap pockets of air, allowing them to absorb oxygen when the tide goes out. Their moist skin and mouth lining also exchange gases directly with the air — but only if they stay wet.
Instead of fins built for swimming, mudskippers have strong, arm-like pectoral fins that act like crutches. They use them to push, hop, or “walk” across mudflats in search of food. Their bulging eyes sit high on their heads, giving them a wide view of both sky and shore — a perfect lookout for predators.
Males even dig tunnel-like burrows and perform little “push-ups” to attract mates, flicking mud and water in elaborate courtship displays.
For scientists, mudskippers are living clues to how the first ancient fish might have ventured onto land hundreds of millions of years ago — an evolutionary story still being replayed on Indonesia’s tidal flats today.