New Zealand Freshwater Streams
Size: Approx 13cm
Common in most well oxygenated lakes and streams of New Zealand.
Glass-like and transparent when young and about 6cm long.
Delicious but increasingly rare delicacy. Whitebait
is made up of five species of fish and grow up to be inanga, banded kokopu, koaro, shortjaw kokopu, or giant kokopu.
Are similar in size to marine mussels but their shells are thinner because lime salts are less plentiful in fresh water. Fresh water mussel
larvae are parasitic on fish for a week or two of their life cycle, but this does not seem harmful to the host fish. These are a protected species.
Is a brackish water fish and can be found a mile or two up river in all tidal estuaries and coastal rocky seashores. The cockabully
is as much at home in the sea as in our lowland streams.
In the early lifecycle of the southern hemisphere eel
, the small transparent fish swim into waterways as juvenile eels called ‘elvers’. They grow quickly, eating insects, fish and anything else they find edible. Young eels
can climb waterfalls, wriggle over ground from isolated waterholes or lakes to rivers and, finally in mature stages, migrate back to sea to spawn.
The mature female is larger than the male.
The most common species, which grows to more than a metre in length and up to 10 kg. The shortfin eel's
dorsal fin exceeds the anal fin.
Has dorsal and anal fins almost matching. Large eels have been known to eat small fish, rats, young birds and ducklings, dead or alive. Males reach maturity between 11 – 34 years, females 24 – 47 years. They spawn usually just once in their lifetime. ‘Big Mama’ is Napier’s large longfin eel
who was caught in a farmer’s lake and brought to the aquarium in 1990.