最初由 King Kong 发布
But carp are coarse fish, they are VERY reproductive and their huge amount has put some native fish in danger. Fishing for carp is encouraged even according to the Ontario fishing regulation. Your were indeed helping them out!
History of Carp in Canada
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http://www.nexicom.net/~paperboy/carp_history.html
The Carp originated in Asia, where it was farmed for food as early as 400 BC. It slowly spread across Europe, both naturally and by introduction, and was brought to Britain in the middle of the fifteenth century. In 1876, the United States Fish Commission introduced the Carp to North America. These fish from Germany, were put into breeding ponds in Baltimore and Maryland, and for several years were distributed enthusiastically around the country. However, it was soon realized that the introduced Carp were disrupting the natural balance of American and Canadian waters and often displacing the native species, and the emphasis switched from propagation to eradication.
Despite this the Carp remains well established in the USA and Canada. The original, fully scaled Wild Carp is a slow growing, long, wiry and incredibly strong fish which rarely exceeds 20 lbs. In general, the average weight is much less, being only 2 to 5 pounds in most environments.
From this Wild Carp, different strains were produced by selective breeding over the years in European countries such as Hungary, Yugoslavia, Poland and Germany, resulting in a faster-growing, deeper bodied fish known as the King Carp. These larger, heavier Carp now form the basis of Carp fishing in Britain and Europe, although plenty of Wild Carp are still caught in these countries.
King Carp or Common Carp, Mirror Carp, Wild Carp are the most common types found in Canada, they breed in the late spring or early summer. Each ripe female is often accompanied by several males, which chase her and sometimes lift her out of the water in there eagerness to fertilize her eggs.
The spawning can be a noisy business, with a lot of splashing and shuddering as each group of fish crashes through weed beds, reeds and fibrous underwater roots of bank side trees. The eggs stick to the plants, and those which aren't eaten by smaller fish, or even the Carp themselves, hatch after 8 to 10 days. Carp grow quickly, gaining 1 to 3 pounds per year to a maximum of 10 lbs in poor environments, and 20 to 30 lbs in rich waters. Although Carp of 50 to 70 lbs are caught across Europe and North America.
There are two basic forms of King Carp: the Galician and Israeli strains are short and deep bodied, while the Bohemian, French and Lausitz strains are longer and thick bodied. Due to so much selective breeding there are many varieties of these basic forms, and also a range of scale patterns.
At one end of the range is the fully scaled King Carp known as the Common Carp; at the other end, is the near scale less Leather Carp. In between come the Mirror Carps. Fully scaled Mirror has large irregular scales and is arguably the most beautiful of all Carp.
The Linear Carp has its scales in a continuous line running along the lateral line from gill plate to tail. There are also the scattered Mirrors, whose large, individual scales are scattered randomly over the body, and the Plated Mirrors which usually have just a few large, platelike scales, sometimes 3 to 4 inches in diameter, along the lateral line. When they're feeding, they often rummage through the bottom detritus, stirring it up and increasing the turbidity of the water and uprooting aquatic plants. This behavior can ruin the habitat of many species.
As well as the Wild and King Carp, many European waters contain the Crucian Carp (Carassius carassius) which was introduced to England in the early eighteenth century. Crucians can reach weights of over 5 lbs, but such a size is exceptional and 2 to 3 lbs is considered large.
The Crucian is very short and deep, with rounded fins and unlike the Wild or King Carp, no barbules on the mouth. The fish is fully scaled, and its overall color is buttery or golden yellow. It fares best in shallow, warm water lakes, and ponds, pits and canals.
Well there it is a brief history on the Carp. Although most people frown on Carp in there waters, they have been there for a long time. I have not seen any noticeable effect on the native species in Canada, they seem to be co-existing very well.