The Mudskipper is a strange fish: It is rather on land than in the water and can even drown. But he has the panoramic view!
What a strange animal. A fish or rather a frog? The broad head, the mouth and the big eyes act very toad like. If he waddles with his long abdomen on the pectoral fins on land, it is reminiscent of a stranded tadpole. Yet say zoologists: The mudskippers (genus: Periophthalmus) is clearly a fish!
It pleases him only partially in the water. In low tide mud he catches its prey and fled at high tide ever on a tree. If he stays too long in the water, threatening the mudskippers stifle even. He must regularly grab air and his breath water accumulate it. In addition, it is the swallowed air buoyancy – in support of the swim bladder.
For his amphibious double life the little guy is very well equipped. As the gills mudskippers requires mandatory water. For shore leave it closes its gills to the outside so that they do not dry out. But he wears – in chambers behind the gills – a sea-water supply around with them, which he added oxygen. So it can survive for quite some time ashore. Until he swallowed his water reserves during prey capture. Then he must go back into the sea to replenish the depots again. Also under the eyes he has a small liquid reservoir that protects the delicate organs of sight.
Oh yes, the eyes! Slightly elevated they protrude from the fish head. They can be moved individually, allowing a panoramic view. And they brought him his scientific name: Periophthalmus in English round eye. With these eyes the mudskippers can wonderfully staring over the water surface, while his body remains submerged.
But he is most like anyway ashore. And because he can not swim there, as befits a fish, he crawls through the mud: Its pectoral fins are extended to small arms and serve as a lever to move push the fish body. When he wants to go faster, he pushes off with the powerful tail fin and catapulted into a big leap forward. Some species also take advantage of the pelvic fins, to hold on while climbing.
Periophthalmus can also digging – with the mouth. Up to 120 centimeters deep burrows it digs under water in the silt. He always has enough oxygen also at home, he swallows air and lets it in the cave off again, until there is a air bubble in the ceiling. In this oxygen reservoir the mudskippers places their eggs, as Japanese scientists found out of 2009. The researchers used an endoscope to peer into the caves of the Malaysian mud Springer (Periophthalmodon schlosseri): The Spawn hung in the air bladder at the cave ceiling. The young hatch as soon as it comes into contact with water. And then the mudskippers-parents have to drag the air away again. He who walks between the worlds, has it just not easy.
One place to see the mudskippers is on a river boat tour in Khao Daeng.