A Little Bit More
Don’t get the American Eel (considered freshwater) confused with other kinds of eels. There are both marine eels (conger, moray, and snake) and freshwater eels (electric) that are in completely different families from the American Eel, they just look similar and have the same common name of “eel”.
The American Eel (there are eels in other parts of the world too) has one of the largest ranges of any fish species in the world. These eels can be found in freshwater rivers and lakes, estuaries (bays with a mix of fresh and salt water), coastal areas and the open ocean from the southern tip of Greenland, along the Atlantic coast of North America, through the Gulf of Mexico and Caribbean, all the way to Venezuela.
American Eels are catadromous (ka-TAD-row-mus) which means they spend most of their lives in freshwater (sometimes brackish) but return to saltwater to lay their eggs. Baby eels hatch in the Sargasso Sea (saltwater) and then drift for about 9-12 months before entering coastal waters of the western Atlantic. In the autumn, small eels, called elvers at this stage, move into estuaries and although some stay here, many move farther upstream as much as several hundred miles surmounting incredible obstacles such as spillways, dams, falls, and rapids to do so. At this point the eels remain in an area where they’ll live from 5 to 20 years. Female eels grow up to 5 feet long but males only attain about 2 feet. While growing, these eels are active at night feeding on insects, mollusks, crustaceans, worms and other fish.
Once these eels reach maturity, they undergo dramatic changes in physical appearance prior to returning to the sea. At this point the eels stop feeding, their eyes and pectoral fins enlarge, their color changes and on certain autumn nights, they begin their journey back to the Sargasso Sea where they’ll spawn in January and then die, completing an age-old cycle of birth, growth, and death.
Activities
Sargasso Sea
Objectives: Learn more about this “unknown” sea
Materials: Access to library and/or internet
This is an opportunity for students to learn about a rather unknown body of water just off the eastern North American coast called the Sargasso Sea. Although we usually think of a sea as somewhat surrounded by land (Caribbean Sea, Caspian Sea, Mediterranean Sea, North Sea, etc.) this one is completely surrounded by ocean.
Your students should be able to find out all kinds of interesting facts about this area including some of the animals and plants that live there (there’s even a fish and a plant named after the Sea). You may want to assign various topics for them to research or simply let them have an open-ended assignment. In any event, they should be able to come up with animals, plants, currents, temperature, geography, etc from their research.
A few places to find information on the Sargasso Sea:
Key Concepts
Identification, Life Cycles, Populations and Ecosystems
Questions
Do you have a question for a naturalist? Go ahead and ask!
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Posted by jon gustafsoon on July 02, 2006 at 09:56 PM
Q: i just completed a dive to 530 ft sea water and we had alot off eels the diver said the eels was conger eel but what i read the like rock not soft mud.the eel gray and avrage size was about 5-8 ft long
A: You didn't say how your dive was made but sounds like some kind of submersible craft? Impressive! I'm not well acquainted with saltwater natural history but did do a bit of research on your observations. You're right about the Conger Eel spending most time in reefs and rocky places rather than on a mud bottom. Do keep in mind that there are several species of Congers so we can't be sure which one you saw. Also, the size fits with Conger Eels as they do get quite large with some as long as 7 feet. One of the most common species is Conger oceanicus so you might want to google this animal and see if it looks right.
My research indicated that Conger Eels make rather long migrations to spawning grounds to breed. I'm wondering if these eels were on their spawning grounds out in the Gulf so were away from typical habitat? Apparently, as this species approaches breeding condtion, the males' eyes enlarge a great deal and their body configuration changes somewhat so they may look "different" from usual pictures. Wonder if you noticed any of this? Also, these animals tend to be nocturnal and rather solitary so if you saw lots of them in daylight, maybe they were indeed spawning or getting ready to do so. Sorry I can't be more informative but hope this gives you a bit to think about. Thanks for asking.
Posted by Jeremy Springer on March 30, 2006 at 07:38 PM
Q: I was in a drainage ditch near my home in Baton Rouge, LA and I found what I first thought to be a small snake. Upon further investigation I found that it was more eel like except that it had very small legs instead of fins. The creature was about 4" long and had a purplish color. Can you help me find out what it is.
A: Sounds like one of two aquatic salamanders: if it had two pairs of legs — both very small — and no visible external gills, it was a Three-toed Amphiuma. If it had only a single pair of legs behind the head and bushy external gills, it was a Lesser Siren. Both are common in the South in nearly any unpolluted body of water. They are rarely seen because they hide by day in the debris at the bottom of the water, moving about mostly at night. Amphiumas are known to move across land on rainy nights, while Sirens will estivate (summer "hibernation") in mucus-lined burrows during dry spells. In either case — based on its size — the animal you saw was a juvenile.
Thanks for writing.
Posted by Clare Geiman on August 25, 2005 at 10:58 AM
Q: when swimming in a freshwater pond on the coast of Maine (with no outlet to the sea) we saw what at first looked like a small eel. It was about 6 inches long, brownish, swimming in the shallow waters on the edge of the pond, and appeared to have a small fantail and some fin structure. We thought it might be a leech because it appeared to be attracted to our feet. I have tried to identify it by searching for images of both leeches and feshwater eels, with no success. Can you help figure out what this was?
A: Everything you said about your animal made me think leech until you talked about fins. It's certainly possible that your animal simply "looked" as though it had fins even though it did not. Although young eels are found in freshwater along the Maine coast, they shouldn't be located in any land-locked water bodies since they get their via the ocean.
Leeches are rather common in freshwater slow-moving streams, ponds, marshes, and lakes especially in the northern part of the U.S. When swimming (not all species are good swimmers) they undulate either side to side or up and down and can certainly look like an eel. Some species are very colorful and this may have given the impression of fins - so not sure exactly what you saw. Some kinds are rather large and when stretched out, one species is up to 18 inches long!
I've tried to find out what color baby eels would be when they're about 6 inches long and at the coast but am not sure so I can't rule out an eel, based on your color. Take a look at the two sites I have included; one gives info on leeches and the other info on eels. Sure hope this helps you make an ID on this one. Thanks for asking.
Posted by Dianne Ripley on July 24, 2005 at 09:41 AM
Q: I live on the Island of Nevis. Saw in title pool on s/e side of island what looked like an eel or sanke. Stripped like tiger in black bands with yellow gold background. Have tried to identify cannot find could you help me? Curious.
A: Their are no sea snakes in the Caribbean, only eels (morays, snake eels and garden eels.) I suspect, however, what you saw was a harlequin pipefish. They are small fish (15 cm max). Pipefishes are related to the seahorses. You can view an image here: