They Swim The Seas: The Mystery of Animal Migration

They Swim The Seas: The Mystery of Animal Migration — page 1
The watery world is in many ways similar to the mixture of gases we call the atmosphere Water has winds in the form of currents and there are fronts between warm and cold water just as there are between warm and cold air masses Currents flow up and down as well as side to side Freshwater animals living in rivers and lakes are also affected by currents though currents in small lakes are usually much weaker than those in huge seas Fish are more abundant in the earth’s waters than any other good sized animals They are found all over the world in salty oceans and seas and in freshwater lakes rivers streams ponds and swamps In fact there are as many different species of fish as there are of mammals birds reptiles and amphibians put together