4/13/2025 Migratory Magicians: The Complex Life History of the American Eel (Anguilla rostrata)

Pidcock Creek is one of the most iconic features of the Preserve and a recent survey conducted by Heritage Conservancy has turned up exciting news. We are home to a migratory species with a somewhat mysterious life cycle. The American eel (Anguilla rostrata) is a catadromous species. They primarily live in freshwater habitats, but migrate to the ocean – the Sargasso Sea – to reproduce. After hatching, young eels will live in the ocean currents for up to a year until they reach the coast. They then swim upstream and live there until they reach sexual maturity. During this time, they undergo several metamorphoses – egg, leptocephali, glass eel, yellow eel, silver eel (adult). They can live anywhere from 5 – 20(+) years feeding on aquatic invertebrates and small fish at night. In addition to serving as a food source for many creatures, they also serve as transportation hosts for our freshwater mussels. The larval eels transport mussel larvae upstream where they can establish themselves, begin filtering millions of gallons of water each day and serve as a rich food source for local wildlife. These eels can serve as indicator species for habitat quality as they are maturing there for several years.

Once eels reach sexual maturity, they undergo a multitude of physical changes and make their way back to the ocean to breed. This journey can be hundreds to thousands of miles, depending on how far inland the eel starts, and takes several months to complete. Migrating back to the Atlantic Ocean where they were born, adult eels from all over converge, spawn, and die completing their life cycle. This final process, we have yet to observe in the wild.

In recent years, habitat destruction via dams and hydropower facilities has led to population declines. To help protect these long-lived masters of migration, maintaining healthy habitats, population monitoring, and protecting the vital passageways between the oceans and streams is crucial. We are truly thrilled that Pidcock Creek is home to these incredible organisms.

Article by education manager, Santino Lauricella

Photo taken at The Watershed Institute by Seth Siditsky