[uNGu]™ Fish : Mudskippers

Mudskippers
Family Gobiidae

The Mudskippers are perhaps, the most conspicuous fish in our mangroves mainly because they spend most of their time out of water. Uniquely adapted among fishes for terrestrial activity, they breathe by holding water in their mouth and gill chamber, replacing with fresh water when it becomes deoxygenated. By staying damp, the fish can also breathe through its skin. The physiology of mudskippers is remarkable—they can withstand levels of oxygen so low that few animals con survive, they are able to breathe anaerobically for long periods, and endure concentrations of hydrogen sulphide toxic to many organisms.

They have complex courtship and territorial behaviour that sees some species leaping to surprising heights. Mudskippers have their eyes on the top of their heads and their excellent eyesight allows them to spot prey and predators from afar. Their pair of dextrous and muscular leg-like pectoral fins enable them to crawl over the mud, and to even climb trees. To top it all, mudskippers are also good to eat - once they have been kept in clean water for a few days to get rid of their rnuddy taste. In some places (Taiwan, for example), they are even cultured for food. More than five species of mudskippers are found in our mangroves, and theGiant mudskipper, Periophthalmodon schlosseri (to 27 cm) is the largest. It has a black stripe on the side of the body. It tends to live in shaded areas, but also frequents prawn ponds.

Periophthalmodon schlosserishowing black stripe Periophthalmodon schlosseri Periophthalmus novemradiatus Boleophthalmus boddarti

The smaller and more common Dusky-gilled mudskipper, Periophthalmus novemradiatus (to 6 cm) differs from its larger cousin in having separate instead of fused pelvic fins. Both mudskippers are predatory, feeding on small crabs, worms and insects.

On the adjacent mudflats, the Blue-spotted mudskipper, Boleophthalmus boddarti (to 22 cm) hides during high tide in a burrow with an air bubble. It emerges when the tide recedes to graze on algae and detritus by moving its mouth sideways over the mud. They can often be observed sparring with each other with their dorsal fins erect.