species

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

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 most amazing inhabitants of the water depths of the world

1. Fish-drop

One of the most remarkable inmates of the depths. Her look is so not attractive, and bizarre. As a rule, fish-drop lives at depths of 600-800 meters. There were also instances that prefer more extreme depths, namely 1,200 meters.

Prefer to live off the coast of Australia and Tasmania.

This fish is endangered. It is very actively caught and sold by fishermen. Of course, not palatability attract customers, and its unusual appearance.

The fish-drops no muscles, it is composed entirely of a gelatinous mass which density is close to water. It is this anatomical feature allows fish to swim at great depths without spending a large amount of energy.

This fish eats everything that floats by. Generally, its diet consists of molluscs and various.

2. Sea urchin

Some of the oldest animals. They inhabit the Earth more than 500 million years. Today there are about a thousand species of sea urchins. They are divided into two large groups, called: right and wrong. Continue reading