Cornelius' Corner

The American Eel

Cornelius’ Corner: “The American Eel”

Hi readers –

Cornelius’ friend, the American eel, here. Thanks for coming back to read more of our blog series! You’ve likely never seen an American eel at the Grist Mill before. We can be found in the deep pools along the West Branch of Chester Creek.

All of us are born in the Sargasso Sea in the Atlantic Ocean. In October, when we are sexually mature eels, we migrate and swim out of freshwater habitats like lakes, rivers, and streams, down into coastal wetlands and then out into the Atlantic Ocean.

Diagram showing the life cycle of an eel

Life cycle of an eel

In January, we will begin laying our eggs, and then they float to the top of the ocean’s surface. After our eggs get fertilized, they float to the surface, and we hatch out as leaf-like larvae called leptocephalus. This stage lasts between 9 and 12 months. As new larvae we are less than 5 mm in length but we can grow up to 0.25 mm per day! As we grow, we develop fins, gills, and other fish-like structures. Our bodies are see through because we don’t have any pigments, so we’re called glass eels.

As glass eels, we migrate through the ocean following along the Gulf Stream currents, and eventually reaching the Atlantic Coast about a year later. By the time we arrive at the coast, we’ve developed some pigments and have matured into a more adult-looking shape.

In our next life cycle stage (the elver stage), we move into coastal to brackish wetlands which have areas that are a mix of salt and freshwater. From there, we continue to move inland into rivers and streams. Our color changes to a yellow-brown color, and we continue to grow. We’ll spend time in this stage (called the yellow eel stage) growing and maturing into adult eels. In this time, we’ll grow from a little over 4 inches in length to up to 4 feet in length!

Adult eels remain in freshwater rivers and streams for the majority of their lives, and once we reach sexual maturity, we return to the Sargasso Sea to spawn and die. Our typical life expectancy is five years, though some eels can live to 15 to 20 years old.

Thanks to my friend, the American eel, for this post, and thanks to all of you for reading my blog! Stay tuned for more posts. See you at the Grist Mill!

– Cornelius

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There will be no weekday Grist Mill tours offered during the month of January in order to allow time for staff development and project work.

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