Māori Name: tuna
Name Scientific: Anguilla dieffenbachii
Availability: Year round in the North Island, spring to autumn in the South Island
Attributes Weight: up to 20kg
Attributes Length: 0.5–1.2m, reaching 2m
They live mainly in freshwater but migrate and breed in the ocean. In colder regions, the eels hibernate in winter.
Dark brown or grey body with a pale belly. Migrating adults are sooty black with larger eyes, circled with blue. Longfinned eels have a dorsal fin that extends further forward than that of Shortfinned eel (A. australis), and a larger mouth that extends back beyond their eye.
Longfinned eels belong to the Anguillidae family (freshwater eels) and are endemic to New Zealand.
Male Longfinned eels migrate to their spawning grounds at between 12 and 35 years old (average 23 years) and females between 25 and 60 years old (average 34 years). Longfinned eels are thought to spawn to the east of Tonga. Their eggs hatch into leptocephali (transparent, leaf-shaped) larvae that drift in the ocean for some time before they reach the coast of New Zealand. These then change into elvers and swim upstream.
The contemporary commercial eel fishery dates from the mid-1960s when markets were established in Europe and Asia. Eel catches are greatly influenced by water temperature, flood events (increased catches) and drought conditions (reduced catches). Catches decline in winter months, particularly in the South Island. The eel fisheries in the South Island, Chatham Island and North Island were introduced to the Quota Management System from 2000-2004. Minimum and maximum size limits exist across the country. Recreational fishers are limited to a daily bag limit of six eels. They are also an important customary fishery, which is managed by authorisations issued under the fisheries regulations. Indices of abundance for longfin and shortfin eels are available from commercial catch data for those areas that are commercially fished.Monitoring of recruitment is often combined with work to mitigate the effect of hydro-power dams.
Many Longfinned eels are caught on their seaward migration (when they have a higher fat content) or in their freshwater environment, often in fyke nets or traps and pots. They are caught year-round in the North Island and in spring to autumn in the South Island.
Did You Know
Female longfinned eels have been recorded aged over 100 years. These grand old ladies, often two metres or more long, are possibly the largest freshwater eels in the world.
Eels are often smoked, and available as either fillets or pieces.
Unless you are catching your own, eels are usually available as a processed product, rather than a fresh item.