Most fish lay eggs, and it is fertilized outside of their body. Fish that spawn, are called oviparous. But some fish give birth to live fry. Such fish are called viviparous.
To live-bearing are guppies, sword fish. The eggs of these fish are fertilized inside the mother’s body and develop there until the fry. At a certain time they are born. This happens 21 days after fertilization.
The number of eggs, fertilized and deferred, differs greatly depending on the type of fish. Some fish lay eggs and abandon her, without showing her any more interest. This is a fish that produce huge amounts of eggs. Those fish that look after their young, they lay only a few eggs.
Caviar can be of two types. One kind of eggs floats on the water surface, the other sinking. The caviar, which floats, is called pelagic. It is usually tiny, bright and contains a lot of protein. Caviar, which is sinking, is called Donna. It is usually harder and more protein in it. Continue reading
Plaice (Pleuronectes platessa) is a fish of flatfish family.
Flounder is a common name for several species of marine flat fish. Different from other fish very flattened body and location of the eye on one side. Lives on the seabed, some go in the river.
Flounder has oval body, length 25-40cm, small and smooth scales, a crest of bone mounds (mounds 4 to 7) from the eye to the beginning of the lateral line. Eyes often located on the right side. The dorsal fin begins over upper eye. Color: ocular side brown, with reddish or yellow-orange spot in adults, often with light edging; blind side is white, sometimes with dark spots.
Found in the North-East Atlantic, from the White sea to South Portugal, the North sea; the Western Mediterranean sea. Most often over sandy bottom, in the North-East Atlantic from the coastal zone up to 200 m in the Western part of the Mediterranean sea up to 400 m depth. In the sea of Japan (Tatar Strait, between the Gulf of DeKastri and G. Alexander). Also penetrates into brackish water estuaries and lagoons in search of food. Continue reading
Hundreds of thousands of years ago, long before the appearance on Earth of man, the oceans already swam fish. At that time they were the most highly developed creatures.
Since then, they began to develop a variety of ways so that now only some species only vaguely resemble the first primitive ocean fishes.
As a rule, fish has an elongated and tapering shape. People have copied it in the construction of ships and submarines, as it is the best adapted to movement in water.
Most fish use their tail as a motor. With the help of fins and they control their movements. Except for one species of fish, all the others breathe by means of gills. Fish swallows mouth water that passes through the gills and out through the hole. Water also contains oxygen, and it through the gills into the blood of fish, as the air through the lungs in the blood of man. Continue reading