Eels reproduce through a process of external fertilization, where both male and female eels release sperm and eggs into the water. This usually occurs in specific breeding areas, such as the Sargasso Sea for European and American eels. The fertilized eggs hatch into transparent larvae called leptocephali, which drift with ocean currents for months or years before eventually migrating back to freshwater or coastal areas where they mature.
Key Details of Eel Breeding:
- Adult eels undergo a long migration to their spawning grounds, often thousands of kilometers away from their freshwater habitats.
- Males and females release sperm and eggs into the water simultaneously, allowing fertilization to occur externally.
- After spawning, adult eels typically die.
- The larvae spend an extended period drifting in ocean currents during their early development.
- For European eels, the Sargasso Sea is the main spawning location; Japanese eels have a different spawning area near the Mariana Islands.
- Mature eels develop their reproductive organs only during this final migration and spawning phase, sometimes leading to physiological changes like the regression of their digestive system.
This reproductive method and lifecycle were historically mysterious and difficult to observe in the wild, but recent scientific observations and tracking have confirmed these behaviors and locations.
