The Number – Cypriniformes
Family – Priniv
The genus/Species – Serrasalmus nattereri
Length: average 20 cm, in some species up to 50 cm.
Mass rarely exceeding 1.5 kg.
Caviar: a few thousand eggs.
The incubation period is 10-15 days, depending on water temperature.
Habits: constant float huge flocks.
Food: primarily fish; attack mammals, floating or come to the waterhole, and birds.
18 known species of piranhas, 4 of which are dangerous to humans, although fatal cases have been identified. Continue reading
In the Atlantic ocean, the Black sea and off the coast of India dwells amazing and a bit scary fish monkfish .With it is associated a very curious phenomenon. For a long time researchers could not understand why all the water harvested from fish of this species are invariably females. As they multiplied.
Only after the beginning of the heavy deep-sea studies have found out that monkfish has developed a unique mechanism of reproduction. It turned out that the male and female fish monkfish differ in size a thousand times. The female is a large part of his life spent in the coastal zone and can grow up to two meters long, and the male also reaches only a few centimeters and lives at great depths, where is the justice in this world = ( . This was established when he was discovered living at depths of more than two hundred meters tiny fish acerated. Caught deep-sea dredges of acaracide were always males. Only after painstaking research revealed that acerated is (many readers probably already guessed it) a male sea devil, and not a separate species or a subspecies.
To find such a small male helped another feature of the sea devil — the annual migration of huge females on the depth taken by them for the purpose of procreation. Continue reading
Sponges that are sold in stores and are used for washing dishes or cleaning the kitchen, not real. They are made from synthetic materials, although very similar to a real sponge and easy to use.
But these sponges appear in the sea, not in a chemical laboratory. For a long time many were convinced that they know all about sponges. It was believed that this plant, until in 1825 a man by the name of Robert Grant proved that sponges were animals!
It considered the sponge in water through a microscope. And saw trickles of water, which went in through one hole and out through another. Still, for many years, scientists did not know what kind of animal. Thought it was a tiny single-celled creatures that live together in one big colony.
We now know that sponges are the dried skeletons of marine animals belonging to the class of “porous”. This is a pretty significant group of animals. Although sponges are one of the lowest forms in the animal Kingdom, their structure is quite complicated. Continue reading