Nitrogen metabolism in the aquarium: (1) Forage (2) NH 3 . (3) NO 2 . (4) NO 3 . (5) H 2 O. (6) Lighting, (7) Fertilizer (8) O 2 . (9) CO 2
Aquarium (lat. aquarium ) — transparent container for permanent keeping of aquatic organisms.
It typically refers to a home aquarium (room) aquarium for keeping fish aquarium in home; for technical reasons, the maximum volume of such a tank is usually less than one cubic meter. Public aquariums . intended for demonstration to the audience of aquatic flora and fauna existing in the structure of zoos or as separate spectacular educational institution, can be up to 7500 m3 in volume.
To maintain the biological balance in the aquarium used a variety of tools: aerators, mechanical and biological filters. thermostats. thermometers and much more. Description simulation of the ecosystem in an enclosed artificial pond and various aspects of breeding fish deals aquarium. Continue reading
Walleye is a fish that belongs to the family percidae. The weight of this large predator in good conditions can reach 20 pounds. And at length it can grow up to 125 centimeters. But such specimens in the Moscow region’s reservoirs are rarely caught. Perhaps walleye weighing over 10 pounds can be caught only where it is specially bred, and fishing is possible only for a fee.
It should be noted that a Zander weighing more than five pounds is for the angler with a good catch. It is quite an aggressive predator. At a young age he eats planktonic crustaceans, but reaching lengths of 20-30 mm, begins to hunt for fish, he also eats eggs.
Larger perch fed in most cases by fish (he eats bleak, Eltsov, minnows). However, this voracious predator may pounce on a large earthworm, and not refuse to eat river shrimp. As for bait for fishing, it all depends on the time of year. For example, in spring you can use practically any bait, because the predator is starved over the winter, and in summer and autumn it is best to use live bait. Continue reading
Sharks are one of the most formidable inhabitants of the ocean. The lack of bone tissue and Gill covers, especially the structure of scales, and many other features of the structure speak of their ancient origin, as confirmed by paleontological data the age of the first fossil remains of sharks is determined approximately 350 million years. Despite the primitiveness of the organization, shark — one of the most perfect predatory fish of the ocean.
Over a long period of existence they managed to adapt perfectly to life in the water column and now successfully compete with bony fish and marine mammals. Unlike bony fish sharks and rays don’t spawn and lay their large, covered with a Horny shell eggs or give birth to live young.
The highest values reach whale (up to 20 meters) and the so-called giant shark (up to 15 meters). Both these and others, like baleen whales, they feed on planktonic organisms. Wide and gaping jaws, these sharks move slowly in the midst of clusters of plankton and filter the water through Gill openings covered by a network of special outgrowths of surrounding tissue. Giant shark profiltruyte an hour to one and a half thousand cubic meters of water and remove all organisms larger than 1-2 millimeters. Continue reading