The Complete Aquarium [antikvár]

IntroductionfT ish have a truly ancient lineage, one stretching back more than 400 million years. By way of comparison, whales, masters of the great oceans as they seem to us, have existed for just 55 million years; and mankind, the merest flicker of geological time - a few hundred thousand years. Yet, for all the long history of fish, we know surprisingly little about them. Their domain, the aquatic regions of the world comprising some 70 per cent of the Earth's surface, became available to serious scientific study only about 50 years ago. The breakthrough came with the invention of Scuba-diving equipment, which gave ichthyologists an opportunity to observe, relatively unhindered, the natural behaviour of many species of fish.From archaeological evidence, we know that fish have been important as a food source since prehistoric times to coastal tribes and people living near rivers and lakes. Shallow-swimming fish were taken with rudimentary spears or clubs; deeper-swimming ones perhaps with nets. But it was not until ancient Egyptian times that we know that fish were kept and bred not only as a ready supply of food but, more importantly from the aquarist's point of view, because of their ornamental attributes.The Egyptians favored the rearing of tilapia species as a food source, while they kept mormyrids, which were revered as sacred animals, for their beauty. There is also tenuous evidence indicating that goldfish, selectively bred