Carp is probably the most
unpopular fish in Australia. It has a reputation of being an
environmental terrorist, alledgedly responsible for the lack of
native fish in the Murray due to competition and predation, the
turbidity of the water, destruction of native water plants and
much more. Although some research has been done in this area, the
results are not conclusive and much more research is required to
confirm these suspicions. There is no escaping the fact, however,
that Carp have flourished in the River Murray since their
introduction in the 1960s.Carp is a member of the family Cyprindae, which contains 1500 species. No cyprinids are native to Australia. The Carp is characterised by the barbels or "whiskers" on the upper lip. There are two barbels, one short, one long, on either side. Carp have a deeply forked tail and a single dorsal fin that has a stout bony spine at the front. Carp can interbreed with goldfish. These hybrids have reduced or no barbels. Colour varies from bronze on top through to a pale yellow below.
Growth in Carp is variable (dependant upon water temperature and food availability) but generally, males mature at 2-3 years and females at 3-4 years, with an approximate length of 300mm and 350mm respectively. During the spring or summer, Carp spawn in water temperatures of about 17° and 25°C. The famale produces between 80,000 and 1,000,000 eggs depending on its size. The eggs develop rapidly and at 25°C, can hatch in 2 days.
Carp "mumble" in the mud when feeding. Juvenile Carp feed on Zooplankton, as do adults. Adults also eat other invertebrates. Food is sucked in with mouthfuls of inedible sediment and sorted out by the fish's gill rakers and muscular soft patate. Vegetable matter only makes up a small part of the diet due to the Carp having no teeth. The "mumbling" activity associated with feeding may be responsible for uprooting delicate native water plants.
Carp prefer to live in warm, still waters with muddy bottoms and they are more common in wetlands and lagoons than in the main river channels.
NSW Fisheries 1996, Carp
in Australia, Pyrmont, NSW.