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
Floating jellyfish in the sea often struck by its beauty. Such a wealth of shapes, colors, as among the jellyfish, not to meet many animals! Jellyfish inhabit all seas, and some of these sea animals prefer warm waters of the tropics and subtropics, while others liked the cool Northern parts of the oceans.
Some jellyfish can be found at a depth of 10km, and there are jellyfish that do not leave the coastal strip. It is noteworthy that each type of jellyfish is found only on the territory of the area is an animal does not apply to pandemic, that is common everywhere.
The largest jellyfish is Cyanea arctica – chosen by a cool North sea. The age of lanei can be identified by its colour – older individuals are covered with brown and red spots; the young specimens are painted in an intense orange color. 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