Scientific and Common Name
Characteristics of Young & Adult American Eels
The eels are born with small, but well developed eyes. They do have small teeth. A tongue is also present.
Eels have a thick, slimy skin colored olive to brown above, yellowish on the sides, and lighter below. And a single continuous fin running from the dorsal side to the pelvic area. Females average 24 to 36 inches, while the males are somewhat smaller.
Mating & Reproduction
Leptocephali: The leptocephalus is the larval form. Leptocephali are transparent with a small pointed head and large teeth and are frequently described “leaf-like”.
Glass eel: As they enter the continental shelf, leptocephali metamorphose into glass eels (juveniles), which are transparent and possess the typical elongate and serpentine eel shape.
Elvers: Glass eels become progressively pigmented as they approach the shore; these eels are termed elvers. The melanic pigmentation process occurs when the young eels are in coastal waters.
Yellow eels: This is the sexually immature adult stage of American eel. They begin to develop a yellow color and a creamy or yellowish belly. In this phase, the eels are still mainly nocturnal.
Silver eels: As the maturation process proceeds, the yellow eel metamorphoses into a silver eel. The silvering metamorphosis results in morphological and physiological modifications that prepare the animal to migrate back to the Sargasso Sea. The eel acquires a greyish colour with a whitish or cream coloration ventrally. The pectoral fins enlarge to improve swimming capacity.
American Eels are unique because they are one of the few fish that are catadromous. This means they spend most of their lives in fresh water, but return to the sea to breed.
They have the ability to absorb oxygen throught their skins to breathe. This allows them to survive out of water for several hours. If an eel is found doing this, it is most often on a damp, rainy night.
Eels can also travel by underground waterways. This explains how eels are found in ponds that don't have a stream leading to it.
Niche in the Food Chain
Predators of eels include larger fish, gulls, and eagles.
The Eels eat in a rotational feeding style tearing parts of the food of by biting on the prey then twisting around so that they rip the meat off.
Ecological/Economic Significances of American Eels
Economic-Global production of eels (Anguilla spp.) increased nearly 20-fold from 1950 to 2007 (Crook 2010), and 90-95 percent of current production is attributed to aquaculture of wild-caught young (FAO 2009, Crook 2010). Eel farming, whether in Europe, Asia or North America, relies on wild-caught juveniles because it has been difficult or impossible to produce viable offspring using captive spawning methods. (Lutz, 2012)
Beebe, W. (2000, January 1). American Eel. Retrieved April 20, 2015, from http://www.fourriverscharter.org/projects/2007 Watershed Wildlife CD/Animal Pages/American_eel.htm
Nedeau, E. (Ed.). (2007, January 1). Restoring a Vanishing Resource in the Gulf of Maine. Retrieved April 20, 2015, from http://www.wildlife.state.nh.us/marine/marine_PDFs/American_Eels_GulfOfMaine.pdf
Painter, T. (2009, January 1). American Eel. Retrieved April 20, 2015, from http://www.fcps.edu/islandcreekes/ecology/american_eel.htm