Previously, there was a hypothesis that stingrays were descended from sharks, but today the hypothesis is refuted by molecular evidence. There are tail-shaped stingrays, which reach a meter in length, stingray-shaped have a more diamond-shaped body, electric stingrays are endowed with electric organs. There are also raylike rajids, which look like sharks. All these units have many kinds.
The largest stingrays can reach a length of about 7-8 meters and weigh up to three tons. These are manta stingrays, or giant sea devils.
Stingrays can reproduce live or lay egg capsules, the so-called “mermaid purse.” These capsules can be of a very intricate shape and represent a shell inside which a fertilized egg is placed.
The coloring of the stingrays is very diverse. The upper side of all the representatives of these cartilaginous fishes is colored under the color of the bottom surface of their vital space, so when the slope lies to the bottom, it almost merges with it.
Stingrays live in all oceans and seas on the planet, as well as freshwater reservoirs. There are both shallow and deep water species that live at a depth of 2.7 km.
The electric shock of the ramp has a voltage of 50 to 200 volts, while the ramps produce not one discharge, but a whole series of electric shocks, up to 100 strokes in a row.
The most dangerous for humans are stingray stingrays. On the tail, these stingrays have a spine up to 37 cm long, which is strewn with poisonous cells. The poison of these stingrays can lead to paralysis, a sharp drop in blood pressure, paralysis of skeletal muscles. The most notorious victim of these stingrays is Steve Irwin, an Australian naturalist.
Since the eyes of the ramp are located in the upper part of the head, and the mouth opening is at the bottom, the stingray does not see what sends to the mouth during the meal.
The stingrays look for their prey not only with sight and smell, but mostly with touch. Their body is permeated with electro-receptors, which notice the slightest changes in the electric field in the environment. Such impulses, for example, arise from the contraction of the muscles of the nearby fish.
One of the main enemies of the slope is a man. For a long time a man uses leather stingrays for making purses, belts, etc. Handles of Japanese katan swords have also traditionally been skinned by stingrays. In addition, in some countries, stingrays are used for food.