Speckled longfin eel
The speckled longfin eel or Australian longfin eel, Anguilla reinhardtii, is one of 15 species of eel in the family Anguillidae. A native of New Guinea, eastern Australia, including Tasmania, Lord Howe Island, and New Caledonia, specimens have recently been found in New Zealand. This was confirmed in 1997 using vertebral counts and DNA markers from eels caught in the Waikato River. Although this confirmation is recent, anecdotal evidence suggests reinhardtii may have been in New Zealand for at least 25 years.
It is found in coastal lagoons, rivers, streams, lakes, swamps and farm dams, but prefers riverine habitats. Their length is up to 6.56 ft (2 m) for males and 5.18 ft (1.58) m for females, and the maximum weight recorded is 35.9 lb (16.3 kg). They can live for up to 40 years.
The body is long and snakelike, roughly tubular. The dorsal fin starts about a quarter of the body length along the back. The jaws contain tooth bands with a separated inner series.
Coloration is a light brown speckled with dark brown, lighter on the underside, the fins being the same color as the body.
Like the other anguillids, speckled longfin eels are catadromous: when they reach maturity, they stop feeding and migrate downstream to the sea, then anything up to three or four thousand km to an unknown spawning ground in deep water. The larvae drift on the ocean currents and eventually reach coastal waters, where they metamorphose into elvers (tiny, semi-transparent eels). From there, they migrate upstream, traversing numerous obstacles “” if necessary, leaving the water and traveling short distances over moist ground. They are well fitted to this task, being able to absorb 50% of the oxygen they need through the skin. Eventually, they take up residence in a lake, swamp, dam or river, where they remain until they reach maturity.
They are carnivorous, eating crustaceans, snails, frogs, molluscs, insect larvae, and fish including elvers and native trout.