The freshwater habitats of New Zealand are home to the New Zealand Longfin Eel. These eels can grow up to 6.6 feet long, with females reaching this maximum size. Hence, the New Zealand Longfin Eel is one of the world’s largest eel species. 

These eels are olive green to brown. Their long dorsal fins are notable features; they undulate gracefully, helping them move quietly during nocturnal hunts. Despite their size, they are shy creatures.

During the day, they hide in shadowy locations, such as submerged logs or unseen crevices. Their keen sense of smell helps them find prey, primarily invertebrates, small mammals, and other fish.

Moreover, these eels can live for over a century but only breed once. During the breeding season, they embark on an epic journey from their freshwater homes to their spawning grounds in the deep Pacific Ocean near Tonga. After mating, the eels die. Then, thousands of minute larvae return to New Zealand, guided by the waves.