Hidden beneath the calm waters of New Zealand’s rivers and lakes lies one of the country’s most extraordinary creatures—the New Zealand longfin eel (Anguilla dieffenbachii).
This ancient species, deeply intertwined with Māori culture, embarks on a once-in-a-lifetime migration spanning thousands of kilometers.
However, despite its resilience, the longfin eel faces growing threats that put its future at risk according to Discover Wildlife.
A Life Spent in Freshwater
New Zealand longfin eels are among the longest-living freshwater fish, with lifespans reaching 80 years.
They spend most of their lives in rivers, lakes, and wetlands, growing slowly over decades. Unlike many fish species, longfin eels are catadromous, meaning they mature in freshwater but migrate to the ocean to reproduce.
During their early years, they play a crucial role in the ecosystem, helping to control fish populations and contributing to the balance of freshwater habitats.
Their significance extends beyond biology, as Māori people consider them a taonga (treasure) and have relied on them as a cultural and food resource for centuries.
![]()
Read also:
The Epic Migration
When the time comes—often between the ages of 25 and 80—longfin eels undergo a dramatic transformation.
Their bodies darken, their eyes enlarge, and they stop eating. Then, they begin an incredible journey of over 6,500 kilometers to the deep ocean waters near Tonga.
Once there, the eels spawn in depths that remain a mystery to scientists.
Females lay millions of eggs, which are fertilized by males before both sexes die.
The newly hatched larvae drift on ocean currents, slowly making their way back to New Zealand.
After more than a year, they arrive as transparent glass eels, ready to begin the cycle once more.
Threats to Their Survival
Despite their fascinating life cycle, longfin eels are now facing significant threats. Habitat destruction from wetland drainage, pollution, and dam construction has obstructed their migratory paths.
Overfishing has also contributed to population declines, as their slow growth and late reproduction make them particularly vulnerable.
Conservationists and Māori communities are working to restore habitats, implement fishing regulations, and create eel-friendly water passageways.
Without these efforts, one of New Zealand’s most iconic species could disappear forever.
The New Zealand longfin eel is a symbol of endurance, tradition, and ecological importance.
Its incredible journey to the ocean and back is a testament to nature’s wonders.
By taking action now, we can help preserve this species for future generations, ensuring that these remarkable eels continue to thrive in New Zealand’s waterways.
Our team may have used AI to assist in the creation of this content, which has been reviewed by our editors.
![]()
Read also: