Judy Cook, age 15, of West Roxbury, Mass
What is the life story of our common eels?
The dark and slithery eel enjoys life in muddy creeks and fresh‑water streams often hundred of miles from the sea. Eel meat is a tasty dish, but no one ever could breed the long, slippery fish for market. They can be shut in a creek and live for 50 years ‑ but they will produce no babies. The strange life story of the eel puzzled the Old World and the New for many centuries.
Until about 80 years ago, no one knew the life story of the eels or where they went to breed. Some people thought that Mother Nature made them from the mud in their favorite streams, others suggested they developed from horse hairs fallen into the water. But the truth was even stranger than these fantastic ideas. For the story of the eel you finding a creek or muddy stream began in weedy waters of the Atlantic between Bermuda and the Leeward Islands. And the story of every lucky eel will someday end there in the warm, Sargasso Sea.
This patch of weedy water, about a mile deep, is the breeding grounds of the snaky oels that live most of their lives in the freshwater streams of Europe and North America. Here the fishy eggs hatch into larvae and here the older eels return to lay more eggs. Though the breeding grounds overlap to some extent, the European aid American eels do not mix with each other.
The eggs, teeming billions of them, are laid 650 to 1,000 feet below the surface. There they hatch into larvae which look like glassy little willow leaves. As they rise to the surface, many of the larvae are devoured by hungry enemies. Soon the teeming swimmers set out on their separate voyages. The America‑bound eels will reach land in about a year, those bound for Europe have three long years of ocean travel ahead of them.
Boys and girls together, the teeming youngsters cross the watery wastes with no landmarks, no older eels to guide them. In some mysterious way they know and follow by instinct the route taken by their ancestors for generations. They reach our rivers looking like glassy little snakes about two inches long. The boys stay here but the girls travel on up the fresh‑water streams. In the fresh and brackish waters, the young swimmers turn dark and we call them elvers.
Some of the females will travel hundreds of miles, often crossing the land from one creek or pond to another. After ten or 12 years, each female feels an instinct which she must obey. She makes her way back to the sea, reaching the brackish water where the males are waiting in the fall. Countless other females join the troupe and together they swim back to the distant breeding grounds to lay their eggs. The parent eels then all perish there in the same weedy water in which they were born.
The eel, of course, is a fish and takes oxygen from the water through a pair of gills. On her trips over the land from creek to pond, the eel also can absorb oxygen through her damp and slithery skin. For this reason, she tries to keep to the dewy grass and she makes these land trips only at night.