Jeff Somerfield, age 12, of Conestoga, Pennsylvania, for his question:
What exactly is an eel?
This slipperiest of slippery creatures is a fish who looks like a snake. At least he does when he reaches the adult stage of his life. This is when we find him slithering around muddy ponds and freshwater streams. Actually, this particular eel is a female, for only she makes the daring journey from the sea, traveling perhaps halfway across the continent. The males congregate near the shore, often where wide rivers join the sea.
The eel you catch in a creek looks for all the world like a large water snake. However, she has fishy gills to absorb dissolved oxygen, fishy fins and small fishy scales embedded in her slippery slithery skin. Her fins have no spines like those of test fishes and on dry land they may not be noticeable. In the water, they look like pieces of soft grey chiffon.
As she swims, she waves the pair of small fins, placed near the gill slits on the sides of her head. She also waves a long caudal fin that grows from her lower spine, around the tip of her tail and under her body. By wriggling her supple spine and waving her filmy fins, she can travel far and fast. She also manages to travel over land from one pond or stream to the next one. She makes this bold journey at night and survives on oxygen from the dewy grass or by absorbing it from the air, directly through her moist skin.
These fresh water eels are related to the whopping conger eel and also to the bad tempered moray eel that intimidates small creatures off the coral reefs. But they are not related to the shocking electric eel, lurking in murky rivers of South America. All our freshwater eels are more or less grown and for a long time nobody knew how, when or where the youngsters originated.
It took several decades to solve their secret life story and the facts are more amazing than fiction. After several years, when the fresh water females reach a length of from three to six feet, they migrate back to the sea often from hundreds of miles inland. Near the mouths of rivers and in salty lagoons, they rendezvous with groups of males. This is where the males stayed when the females went ashore.
Together, the males and females voyage to their breeding grounds near the Bermuda Islands. There they rendezvous with other groups of adult eels that have voyaged across the Atlantic from western Europe and Africa. In a short time, they lay their eggs and then die. The hatchlings look for all the world like ordinary young fishes. They soon leave their fabulous breeding ground and begin the long journey back home, with no adults to guide them.
It takes the youthful eels a year or more to reach the shores from which their parents migrated. Meantime, they grow to look more like eels and less like ordinary fishes. They arrive along the shallow shores in countless numbers, where many are devoured by sea birds. The surviving males and females segregate themselves and the females make their way into fresh inland waters. The males wait near the shore for the next migration back to the mid Atlantic.