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| Illustration credit: Texas Parks and Wildlife |
American eel
Scientific Name: Anguilla rostrata
"Anguilla" is Latin for eel.
"rostrata" means 'beaked' in Latin.
American Eel are unusual in that they spend much of their lives in fresh water, but return to the open ocean to mate and reproduce. The epic journey of young eels ends up in small tributary streams along the coast of North and Central America, but because they can't jump and are relatively poor swimmers, eels are easily blocked from reaching their destinations.
American eels have always been a valuable food resource, beginning with indigenous peoples and extending to recent commercial fisheries. At its peak, the eel harvest accounted for almost half of the value of the Lake Ontario commercial fishery. However, the number of eels entering the Upper St. Lawrence River and Lake Ontario has declined dramatically since the early 1980's. Instead of 25,000/day climbing an eel ladder, the numbers have dropped to less than 100/day in some years. The American Eel is in decline across its entire range. Potential causes for these losses include:
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- turbines
- dams and culverts
- overfishing (the catch per unit effort has been generally dropping in the St. Lawrence since the early 60's)
- parasites
- habitat loss
- changing ocean conditions.
In response, federal and provincial governments, including the government of Ontario, have begun eel stocking, cancelled commercial and recreational harvests, put in eel ladders, and coordinated management efforts. It has been identified as an Endangered Species in Ontario.
Description
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| Illustration credit: US Fish and Wildlife Service |
- Long and snake-like.
- Small head.
- No chin barbel.
- Dorsal fin continuous with caudal and anal fins.
- True jaws (i.e., no sucking disk like lamprey have)
- Adult, freshwater form is yellow to olive-brown.
Similar To
- bowfin
- burbot
- lampreys
Key Identifying Features
- Long, snake-like body.
- Continuous rear fin.
- Pectoral fin but no pelvic fins.
Size
- Large females: 76.2 to 101.6 cm (30-40 in.); males to 61 cm (24 in.) .
- Average female weight: 1.1 to 1.6 kg (2.5-3.5 lb.; maximum is 16 lb).
- Ontario record: weight – 2.3 Kg (5.1 lb.); length – 97.8 cm (38.5 in.); Ottawa River.
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| Global Distribution of American Eel (Fisheries and Oceans Canada, American Eel, Underwater World. Reproduced with the permission of Her Majesty the Queen in Right of Canada, 2006.) |
Distribution and Habitat
- Found along the eastern coast of North America and inland through Lake Ontario and the American Midwest, as well as parts of Central and South America.
- Adults mate and reproduce in parts of the Sargasso Sea.
- Inland, generally in larger rivers and lakes, usually near the bottom.
- In crevasses or hollow logs, or buried in the sand, gravel or mud, during the day (feeds at night).
Food
- Juveniles: plankton, aquatic insects, small crustaceans.
- Adults: insects, crustaceans, clams, worms, fish and frogs.
- A voracious night feeder.
Predators
- Larger fishes on juveniles, including larger eels.
- Fish-eating birds on adults.
- Humans.
Reproduction
The life cycle of the American eel involves several stages.
It begins in the ocean when the eel larva, called the leptocephalus, hatches from the egg. The leptocephalus, carried in the Gulf Stream, changes into a glass eel (a more elongated, eel-like shape) near the coast and migrates inland into streams, rivers and lakes to grow and evolve into the elver (a small version of the adult eel). In fresh water, the elver grows into the larger yellow eel and then finally into the silver eel (almost full-grown). The silver eel then migrates back to the Sargasso Sea after 10 to 25 years in fresh water and spawns, thereby beginning the cycle once again. OMNR (created by Rob Slapkauskas)
Management Tips
- Eel is tasty and nutritious, but any eels caught should be returned to the water immediately due to low populations.
- Protect habitat and habitat quality.
- River blockages should be discouraged where spawning runs are known to occur.
- Consider use of eel ladders where blockages are unavoidable.
- Use "best management practices" with respect to urban and rural development, agriculture, forestry and other industry.
- Ensure that septic systems are working properly.
- Reduce hard surfaces such as concrete near water bodies which results in higher water run-off temperatures.
- Reduce greenhouse gas emissions driving climate change, which contributes to increased water temperatures.
- Respect recreational and commercial fishing regulations.
