environment

Sea, river and lake fish

We all know that water is life. Without water can’t live no living creature. And the first life originated in water. Fish one of the many live organisms living in the aquatic environment. They live in the oceans and seas, rivers and lakes. You can see them in the pond and the stream, in the waters of caves and even in puddles. In nature, there are over 25,000 species of fish, and they are divided into two classes: Bony fish (more than 23 000 species); Cartilaginous fishes (9000 species).

To the class of cartilaginous fish include sharks, rays and chimeras. To the class of bony fish include salmon. okuneobraznyh. preobrazenie. clupeiformes. Cypriniformes, catfishes, wildcookie, flatfish, coloscopie.

Fish are cold blooded vertebrates. their streamlined body covered with scales. They breathe with gills, and with the help of fins and tail to swim. Water entering the body through the mouth, passes through the gills, and spilling over her holes. Oxygen enters the bloodstream of fish through the thin membrane of the gills. Do fish have paired fins (pectoral and abdominal), which are located on the sides and unpaired, located on the median vertical plane of the body (back, tail, and anal). Fins help fish to steer, brake, accelerate and keep the balance. Continue reading

The food chain, Sea

“Natural systems” – Global. The continents and oceans. Zonal natural complexes. Savannah. The natural areas. Climate. Taiga. Major. The lower part of the atmosphere. Flora. The Arctic desert. “Component”-in translation from Latin means “a constituent part of a whole”. J. Lamarck. Mixed and wide kristenye forest. The whole biosphere.

“Diversity of organisms” – Plants. HOMEWORK: PREPARE FOR WRITTEN TEST EXAMINATION OF THE ENTRIES IN THE NOTEBOOK. 2. Aquatic environment (fish, shellfish, seaweed, whales, jellyfish, etc.). Viruses. 4. Land-air-water (waterfowl, dragonflies, mosquitoes, etc.). 3. Terrestrial-aquatic (amphibians, crocodiles, marine turtles, etc.).

“Habitat” organisms – Each organism adapted to life in a particular environment. Environment – the conditions surrounding the organism. Distinguish between land– air, water and soil environment. Adaptations of plants. Well developed organs: root, stem, leaves, etc. Adaptations for pollination: bright color of flowers, the fragrance of Fixtures to maintain moisture. Continue reading

Catfish: aquarium species

Almost all members of the family of catfish unpretentious, so they are recommended even for beginner aquarists. But still some features to care for them.

In a group of catfish includes more than 200 species of fish, but in the aquarium you can hold not all members of this family. This is due to the physiological characteristics of individual species.

Some catfish in adulthood reach an impressive size, so they begin to pose a danger to small inhabitants of the aquarium. In addition, there are breeds which differ quite aggressive in nature, so they too are not suitable for keeping with other fish.

Popular species of catfish

Of course, you can only breed catfish, but the majority of aquarists prefer to choose peaceful members of this large family that they get along with other Pets.

The most popular species suitable for aquarium rearing are: Continue reading

The construction of ponds for fish farming
The pond is an artificial pond created for fish breeding. For the construction of ponds it is best to use natural depressions, such as depressions and gullies. It is preferable…

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FEEDING FISH FEED MIXTURES
The main methods of intensification of pond fish farms are feeding fish and fertilizing ponds with increased stocking density of fish per unit water area. Natural forage base of the…

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