Species at Risk

The American Eel

Anguilla rostrata

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Where is it?

Range and Distribution

The range of the American eel extends from northern South America to Greenland. In Atlantic Canada, they have been found in all freshwater habitats, as well as estuaries and coastal marine areas connected to the Atlantic Ocean all the way north to central Labrador. This large-scale distribution of a single population is referred to as panmixia, which means that all members of the species mate randomly within a single breeding population.

Range and distribution
Range and distribution
© Parks Canada

Reproduction and Life Cycle Habitat

Although adult American eels can be found over a very large geographic range, they all spawn in a single location: the Sargasso Sea, a large expanse of the Atlantic Ocean east of Bermuda. It is thought that a single female may release up to 20 to 30 million eggs. After these hatch, eel larvae, called leptocephali, may drift for months on the currents of the Gulf Stream before finally making their way to coastal areas. By the time they reach the coast of North America, they are 5-7 cm in length and have changed into the next life stage in which they are called glass eels, so named because they are completely transparent. Once they enter freshwater estuaries (where rivers meet the sea), they begin to gain colouration and they develop into the next life stage, known as elvers. Elvers may settle in coastal bays or estuaries, or migrate into freshwater rivers, ponds, and lakes. Here they transform into yellow eels as adults, and then, from 4 to 25 years later, into maturing silver eels that migrate back to the Sargasso Sea to spawn and die. The oldest captive eel on record lived for 88 years.

Reproduction and life cycle habitat
Reproduction and life cycle habitat
© Ontario Ministry of Natural Resources

Habitat

Eels are catadromous, meaning they live in freshwater as juveniles and adults, and spawn in the ocean once mature. Yellow eels occupy every type of accessible freshwater habitat, as well as estuaries and sheltered bays. As they grow into yellow eels, individual adult eels will often migrate between salt and fresh water, inhabiting estuaries and bays in the summer, and then moving back up rivers and lakes in the winter. Eels bury themselves in the mud during the daytime in summer, and around the clock in winter.

Feeding

Larval eels appear not to have a functional digestive system, and may acquire food by absorbing dissolved nutrients. Small yellow els eat invertebrates, but larger ones rely mostly on fish. Once they begin to metamorphose into silver eels and return to the sea, they will no longer eat, forgoing energy spent on feeding in favour of conserving resources for the development of their sexual organs.

Aboriginal Significance

For the Mi'kmaq, Wolastoqiyik and Passamaquoddy, the American eel (Katew) is considered a spiritual being and is referred to in Mi'kmaw legends. In addition to its spiritual significance, the American eel was and still is an important food source with medicinal properties and is a ceremonial figure and symbol. In the past, Katew was a staple food source throughout the year; however, it was especially important during the onset of winter and spring when environmental conditions prohibited the Mi'kmaw community from harvesting other fish. One of the various medicinal properties of the eel has to do with the characteristics of its skin. Given its unique ability to be tightened considerably without tearing, eel skin was often used to wrap sprains. It was also worn next to the skin to provide relief from cramps, rheumatism, headaches and lameness. Katew was also used to create decorative ornaments such as a string to tie around hair, described in the legend “Sakklo'pi'k” as being made from eel skin, porcupine quills and sinew.

What is it? | Where is it? | Why is it in danger? | What is Parks Canada doing? | Links