Dana Romaine, age 8, of High Point, N.C., for her question:

Do fishes have hearts?

Yes, a fish has a heart that pumps red blood through his body. It is not as fancy as a human heart, but it works very well for the fish. The human heart is more or less hollow and inside it there are four little rooms, called chambers. A fish's heart has only two inside cham¬bers. His veins and arteries connect to his heart and to his gills. From there they circulate his blood around and around his body. The circulating blood carries dissolved food and oxygen    and collects waste materials.

Used blood flows into the heart and the heart pumps it to the gills. There it gives up its waste carbon dioxide and takes fresh oxygen. The fresh blood flows on another trip through his body    and back again to his heart. A fish's simple little heart has only two chambers, but it pumps day and night to keep blood circulating through his body.