Type of feed fish are divided into four groups:
– benthos feeders — fish, feeding on small organisms living on the bottom or near the bottom (benthos), sturgeon, grayling, bream, ruff, etc
– planktology — fish feeding on organisms living suspended in the water column (plankton), Zope, sabrefish, bleak, verhovka, etc.
– mixed feeding — fish feeding on organisms such as benthos and plankton, — roach, bream, IDE, Dace, etc.;
predators — fish that feed on other fishes or animals of their own species — pike, pikeperch, perch, Chub, burbot, catfish, trout, salmon of the Danube. Continue reading
The inhabitants of the Caspian sea. Animals of the Caspian sea is represented by 1809 species, of which 415 are vertebrates. In the Caspian sea registered 101 species of fish, it is focused the majority of the world’s reserves of sturgeon, as well as freshwater fish such as roach, carp, perch. The Caspian sea is the habitat of fish such as carp, mullet, sprats, Kutum, bream, salmon, perch, pike. In the Caspian sea is also home to a marine mammal — the Caspian seal.
The world grade 4
a summary of other presentations
“Domestication of animals” – Near the man began to live animals. Information about the place and time of domestication of animals. The reindeer herding. The dog was domesticated very early. Reducing the size of the brain. To find out what animals the ancient people tamed. Sheep. People began to domesticate bees. Goat. Ancient tour. Buffalo. Pigs. The man of the stone period. Geese. Chickens as poultry. Cow. Foci of domestication of the horse. The size and shape of the body. Continue reading
4 July 1819 from Kronstadt went on a circumnavigation of the sloop “Mirny” and “Vostok”. The result of the expedition was the discovery of Antarctica. We decided to compile a list of the most interesting animals that inhabit this continent.
Weddell seal – the southernmost not only beast, but also one of the most endearing animals. Pretty faces of these large-eyed mammals can be admired for hours. Seal inhabits the entire coast of Antarctica, the number is estimated at about one million individuals. This animal is a beautiful diver. Adult seals can hold their breath for an hour and is able to forage for food at depths of 800 meters.
Blue, or Blue, whale . inhabiting the waters of the southern ocean, is not just one of the animals that have managed to adapt to life in harsh conditions. This is primarily from the most giant animals on our planet is now inhabited and ever. Its length can reach four hundred feet, and the weight often exceeds 150 tons. Compared with humans, this animal looks like a giant floating mountain. One only the heart of a whale may weigh more than a ton. Unfortunately, as a result of uncontrolled whaling a huge number of blue whales have been destroyed, but now their numbers are slowly recovering. Continue reading