11004-39001 Western Mosquito fish (Gambusia affinis) male (foreground), and female. Gambusia were released in New Zealand in the 1930s to control mosquitoes, but as with a number of other countries they soon became pests competing with our native fish. Today they are classed as an ‘unwanted organism’ under the Biosecurity Act 1993, and it is unlawful to possess or release this fish. Their high density populations reduce galaxiids in shallow lakes and still-water habitats, and they may also affect mudfish. They also displace native bullies from shallow, marginal waters of lakes in summer months. Auckland *
11004-39014 Western Mosquito fish (Gambusia affinis) large female. Gambusia were released in New Zealand in the 1930s to control mosquitoes, but as with a number of other countries they soon became pests competing with our native fish. Today they are classed as an ‘unwanted organism’ under the Biosecurity Act 1993, and it is unlawful to possess or release this fish. Their high density populations reduce galaxiids in shallow lakes and still-water habitats, and they may also affect mudfish. They also displace native bullies from shallow, marginal waters of lakes in summer months. Auckland *
DSC_4839 Feral guppy (Poecilia reticulata) adult male. Guppies are aquarium escapees and have been present for many years in geothermal waters near Reporoa, in the central North Island, they may have been introduced into New Zealand as early as the 1920s. Guppies take their name from Robert John Lechmere Guppy, who was himself, shipwrecked on the coast of New Zealand in 1856. After living with Māori for two years and mapping the Taupo area, Lechmere moved on heading for Trinidad where guppies occur naturally in the wild *