Wednesday, June 15, 2011

Perches


Freshwater perches have long been popular with anglers, and this has resulted in their introduction to waters far away from their natural area of distribution; even to different continents.

The best-known member of this large group is the Eurasian or common perch, which can now also be found in the Azores, Cyprus, South Africa,Australia, and New Zealand. It is a predatory species. Another kind of perch, the yellow perches, whose distribution extends in a broad band running from the eastern United States through to parts of Canada and west to Ohio and Illinois, has very similar habits. There are now fears that the yellow perch could be at risk from the ruffe, a species of perches originally from Europe but introduced to parts of North America and now established in the Great Lakes.

Breeding Behavior
Female fantail darters prefer to mate with males already guarding clutches of eggs. Those males which have not mated before, however,will develop fleshy knobs on the tips of the spines of their first dorsal (back) fin. These are identical in appearance to the eggs laid by female darters. As a result, these so-called egg mimics serve to attract a female to the nest site of the male. The female of perches will then enter the area beneath a rock where he has excavated a nest, spawning there and leaving him to care for the brood.

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