fresh water in the spring after spending 4–6 months at sea. As at 2016 spawning has only been recorded as being observed in the wild once. It occurs during autumn/winter and the eggs (first discovered in 2013) are placed among vegetation along the banks. The species has a relatively high fecundity, each female producing several thousand eggs. Typically for amphidromous galaxiids from New Zealand, the eggs develop in semi-dry conditions on land for a few weeks and are then flooded by rising water. The best hatch rates for the eggs are in fresh water at a temperature of about . Although primarily amphidromous, some populations exist permanently in land-locked stream systems, showing they can complete their life-cycle in fresh water. Maturity is reached at 2–3 years old. The oldest known individual, which was long and weighed , was estimated to be 21–27 years old based on its otolith. Adults prefer slow-flowing waters in lowland streams or pools. They usually use cover such as overhanging vegetation, logs, undercut banks, or debris to lurk, awaiting passing prey. They prefer water temperatures between , but can live outside this range; their rarity north of Auckland is probably related to temperature. Their diet includes aquatic and terrestrial insects, freshwater crayfish (Paranephrops spp.), spiders, and occasionally other fish. They are generally nocturnal and slow-moving. Conservation In 2014, the New Zealand Department of Conservation classified the giant kōkopu as "At Risk: Declining" under criterion "B(1/1) - 20,000–100,000 mature individuals, predicted decline 10–50%". The giant kōkopu has been rated as "Vulnerable" by the IUCN since 1996. Primary reasons for their decline include ongoing drainage of wetlands, drain clearance, and land-use changes, particularly the expansion and intensification of dairy farming. Other threats are loss of riparian vegetation and introduced salmonids (trout). Giant kōkopu have been successfully bred in captivity. The species is highly prized as a traditional food and is considered to have potential in aquaculture. References External links Giant kōkopu discussed on RNZ Critter of the Week, 20 April 2018 Galaxias Endemic freshwater fish of New Zealand Fish described in 1789 Taxa named by Johann Friedrich Gmelin