Echinoderms animals that include marinestar, - representatives of a very special group. They are not like anyone. These marine inhabitants cause many questions, among which the following are of particular interest: “What does a starfish eat?”, “For whom is it a mortal threat?”.
These unusual sea bottom decorationsexist on the planet for a long time. They appeared about 450 million years ago. There are up to 1600 kinds of stars. These animals inhabit almost all the seas and oceans of the earth, whose water is quite salty. Stars do not tolerate desalinated water, they are not met in the Azov and Caspian Seas.
Rays in animals can be from 4 to 50, sizes range from a few centimeters to a meter. The life span is about 20 years.
Sea dwellers do not have a brain, but on every ray there is an eye. The organs of vision resemble insects or crustaceans; they clearly distinguish between light and shade. Many eyes help animals successfully hunt.
Stars breathe almost through the skin, so it is very important for them to have enough oxygen in the water. Although some species can inhabit the decent depths of the ocean.
It is interesting how to breed, how to eatsea stars. Biology refers them to the class of invertebrate echinoderms. The starfish has no blood as such. Instead, the heart of the star pumps seawater through the vessels, enriched with some trace elements. Pumping water not only nourishes the cells of the animal, but also helps the star to move by pumping fluid in one place or another.
Starfish have a radial scheme of the structureskeleton - rays depart from the central part. The skeleton of sea beauties is unusual. It consists of calcite and develops inside a small asterisk practically from several lime cells. How and how starfishes feed depends largely on the characteristics of their structure.
These echinoderms have on their tentacles special pedicellaria in the form of tweezers at each tip of the outgrowth. With their help, the stars hunt and clean their skins from litter clogging between the needles.
Many are interested in how starfishes feed.Briefly about the structure of their digestive system can be found below. These amazing beauties create the impression of perfect security. In fact, they are marine predators, voracious and insatiable. Their only drawback is low-speed. Therefore, prefer a fixed delicacy - shells of mollusks. With pleasure, the starfish feeds on scallops, is not averse to eating a sea urchin, a sea cucumber, and even a fish that is carelessly swimming too close.
The fact is that a starfish has practicallytwo stomachs, one of which can turn out. A careless victim, caught by pedicelaria, is transmitted to the mouth opening in the center of the rays, then the stomach is placed on it like a net. After that, the hunter can let go of the prey and slowly digest it. For some time, the fish even drags his executioner behind him, but the victim cannot escape anymore. All that the starfish eats is easily digested in its stomach.
It comes somewhat differently with the shells: it slowly approaches the dish it likes, wraps the shell with its rays, places the mouth opening in front of the sink slot and begins to open the doors.
It should appear at least a small gap in itimmediately pushes the outer stomach. Now the marine gourmet calmly digests the host shell, turning the mollusk into a jelly-like substance. Such a fate lurks any eaten prey, no matter whether the starfish eats scallops or small fish.
The predator lacks any adaptations.to capture prey. The mouth, surrounded by a ring lip, connects to the stomach. This organ occupies the entire interior of the disk and is highly flexible. A gap of 0.1 mm is enough to penetrate the shell flaps. In the center of the aboral side, a narrow short intestine opens, running from the stomach. What a starfish eats depends largely on the unusual structure of the digestive system.
Most sea stars are heterosexual.At the time of love games, individuals are so busy with each other that they stop hunting and are forced to fast. But this is not fatal, because in one of the stomachs, these cunning people in advance tend to postpone nutrients for the entire time of mating.
Половые железы находятся у звезд возле основания rays. When mating, the female and male individuals combine the rays, as if merging into a gentle embrace. Most often, eggs and male sex cells enter the sea water, where fertilization takes place.
In the case of a shortage of certain individuals, the stars can change the sex to maintain a population in a certain area.
Caviar of these sea creatures most often remainsleft to itself until the larvae hatch. But some stars are caring parents: they have caviar on their backs, and then larvae. For certain types of starfish, special caviar bags, well washed with water, appear on the back during mating. There she can be at the parent until the appearance of the larvae.
Absolutely unusual ability of marinestars - reproduction by dividing. The ability to grow a new hand ray exists in almost all animals of this species. A star grabbed by a predator by a ray can drop it like a lizard's tail. And after a while grow a new one.
Более того, если на луче сохранится небольшая a particle of the central part, a full-fledged starfish will grow out of it after a certain time. Therefore, it is impossible to destroy these predators by cutting them into pieces.
Enemies in the representatives of this class a bit.No one wants to mess with the poisonous needles of the sea sky mistresses. Animals still know how to secrete odorous substances to scare away particularly voracious predators. In case of danger, the star can burrow into silt or sand, becoming almost invisible.
Among those who eat starfish innature, dominated by large sea birds. On the shores of warm seas, they become prey for seagulls. In the Pacific, the star is not averse to feast on funny velvet.
Хищницы наносят вред подводным плантациям устриц and scallops - what the starfish eats. Attempts to kill animals, cutting them apart, led to an increase in population. Then they began to fight with them, bringing the stars to the shore and welding in boiling water. But there was nowhere to use these remains. There have been attempts to make animal fertilizer at the same time deterring pests. But this method was not widely spread.
