Forest Preserve District of Cook County, Illinois
Nature Bulletins
Newton Home Page

Introduction and Instructions

Search Engine

Table of Contents



The Eel
nature Bulletin No. 149   April 3, 1948
Forest Preserve District of Cook County
William N. Erickson, President
Roberts Mann, Supt. of Conservation

The eel is a queer fish, both in looks and habits. Try to pick up one of these long snake-like creatures with its slick slimy skin, and you will appreciate the expressions: "slippery as an eel" and "squirms like an eel". It is a startling experience to catch one on a hook when fishing, especially at night.

They have a slender conical head with a large mouth lined with hundreds of small sharp teeth. There is one pair of small fins just back of the head, and a single long fin which, starting a few inches behind the head, runs down the back, around the tail and half-way back on the underside. The color is olive or brownish green above and lighter below. The skin has a faint cross-hatched pattern due to rows of tiny scales imbedded in it.

Eels eat almost any kind of animal food, either dead or alive, and will even crawl out on land to feed, but they prefer fish. Their flesh is rich, rather oily, and considered delicious by many people -- eaten fresh, pickled or smoked.

Eels live in almost all our streams and lakes draining into the Gulf of Mexico and the Atlantic Ocean, except the Great Lakes. They should not be confused with the lamprey, a smaller eel-like animal that is not a true fish, which has invaded the Great Lakes. Apparently, only female eels reach the headwaters of our streams. They grow to be 3 feet long and weigh 3 or 4 pounds. Some grow much larger. The males are smaller and usually remain in the lower courses of our rivers.

Eels reach full growth in 6 to 8 years and then a curious change occurs. Their skins turn silvery, their eyes enlarge, their snouts become more pointed, and they migrate downstream out to sea--never to return. We now know that they, and the eels of Europe and North Africa, migrate to a deep place in the ocean between Bermuda and the West Indies, where they lay their eggs and die. The elongated transparent larvae eventually become miniature eels scarcely 3 inches long, which appear at the mouths of our rivers and swim upstream -- sometimes hundreds of miles.

BUT, the young of our American eels go back to American streams, and those of European or African parents go back to Europe or Africa, as the case may be, with no mothers to guide them.

To return to the Nature Bulletins Click Here!
Hosted by NEWTON

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Sponsered by Argonne National Labs