Transformational life cycle

Ōrea have a fascinating lifecycle. They start their lives as leaf-shaped larvae called leptocephalus, hatching in the tropical waters of the southwest Pacific Ocean, around Tonga and New Caledonia. After drifting on ocean currents for up to 15 months or more, they change into glass eels as they return to New Zealand waters. Their translucent skin begins to darken as they move into freshwater rivers and streams and the glass eels become elvers.

As elvers they migrate upstream in search of suitable lakes and waterways where they can grow into adults. Their final change happens as they prepare to migrate back to their spawning grounds. Their heads become bullet-like in shape, the skin of their pectoral fins, head and back darkens, their belly lightens to a grey or silver colour and their eyes become much larger – all in the aid of helping them on their journey back to the sea and their spawning grounds.

Living taniwha

Seen by some as slimy and scary, the impressive size and appearance of longfin eels may have inspired stories of legendary taniwha (water-dwelling spirit, monster or powerful creature).

Despite their appearance, ōrea are shy and reclusive fish who hide under boulders and logs, or along shaded riverbanks during the day, emerging at night to feed. Their broad diets help them keep our waterways ecologically diverse by managing prey numbers. They were also an important food source for early Māori who would construct weirs across rivers and use specially designed eel pots to catch them for food. 

At the Zoo

We know eels like places to hide during the day, so that’s what we’ve given them. Their habitat recreates a lakeside wharf and provides plenty of shade from the sun.

You can get up close to our long-lived longfins at Te Wao Nui’s Ngā Repo / The Wetlands. Their habitat gives you the best views of this taonga species without getting wet. These curious eels like to swim up to the glass and peer through at our visitors.

In the Wild

Origin: Endemic to New Zealand, but swim to the tropics to breed

Habitat: Rivers and inland lakes, but can be found in all sorts of waterways, usually well inland from the coast.

Conservation status: IUCN – Endangered

How you can help

Longfin eels are currently in decline in part due to loss of healthy wetland habitats, streams and rivers. Another major threat to the long-term survival of ōrea are impediments to their migration, as this means they’re not able to journey downstream to breed. Industrial dams, weirs, culverts, water pumps and perched pipes are all migration barriers.

Restoring and maintaining their preferred habitats go a long way to helping them thrive. Planting natives will create cool, shady areas and removing any rubbish and pollutants will keep the water clean. Also, if you catch a larger eel while fishing, try to return it to the water as gently as possible.