Georgene Arp, age 9, of St. Paul, Minnesota, for her question:
Is there really a fish that climbs trees?
Maybe you had all the Noah's Ark animals sorted out in their proper places on the land or in the water. Then you heard about seahorses and land crabs, flying fishes and diving ducks. These creatures surprise you. But a tree climbing fish seems to be downright impossible.
The animal world is never dull, Experts who study the different creatures get a sur¬prise almost every day of their lives. There are thousands of different fishes and each one has his own ideas about how to get along with the world. An ordinary fish can live on the dry land just about as long as you can live with your head under water. But there are some extraordinary fishes in the world. Sore can live out of water for quite a long time. If all the world's water dried up, maybe you thought that all the fishes would perish. It is nice to know that a few kinds would live, at least for a while.
Most of these unusual fishes live far away in warm tropical parts of the world. There are lungfishes who manage to live for many months without any water. When their streams dry up, they roll themselves in blankets of mud and sleep until the drought ends. There are cute little mudskippers who get left on the beaches when the tide goes out. These frisky fellows leap and hop around like frolicking frogs. On muddy beaches, they sometimes leap from trunk to trunk among the jungle trees.
But the champion of these strange fishes is called the climbing perch. Some people call him the walking perch. This name is closer to the truth because he is not really a great tree climber. But he is a great walker. He can walk, after a fashion, a long, long, way over the dry land. He is not a true perch fish, but he is very good food. The people of Indonesia often take him to market in a basket, and there he lies comfortably alive for a whole day. An ordinary fish would suffocate in a market basket after a few minutes. But all the walking perch needs is a few sprinkles of water.
In the wild, he lives in lazy water, in swamps and still ponds and muddy rice paddies. When his water supply gets too low, he goes walking to find a better one. His walking legs are the round hard flaps that cover his pills. On land, he sticks these gill covers out sideways and uses them like little crutches. Slowly and clumsily he hitches himself along by flopping over first on one side, then on the other. It takes him half an hour to walk about 100 yards and he may walk all night to find a new pond. Along the way he may trundle over a fallen log or part way up the trunk of a tree. But the so called climbing fish is looking for a pond. He is much too smart to waste time searching for it among the tree tops.
The mudskipper and the walking perch are not related to each other. But both of them have relatives in our pet shops. The mudskipper is related to the popular gobies that we keep in our tropical fish tanks. The walking perch is a first cousin of a famous Siamese fighting fish. These cousins have special pockets behind their gills for breathing air as we do. Their gills are very small and they must use these pockets to get all the oxygen they need. Even when they live fn plenty of fresh water, they must come up now and then for a gulp of air.