Sharks (lat. Selachimorpha) is a superorder of cartilaginous fish comprising eight teams, twenty families and about 350 species. Members of the superorder widely distributed in all seas and oceans, there are also freshwater sharks. Most species belong to the so-called real predators, some species, particularly whale, and giant deep-sea sharks, eat plankton.
For many millions of years before the planet appeared the first man, ruler of the prehistoric seas was a shark. The power of evolution sowed on Earth, countless forms of life that could not stand the severe tests and disappeared one after another, as the shark continued to exist. One prehistoric era is succeeded by another, have any amphibians, reptiles, birds, and mammals – the shark continued to exist. Pterodactyls – the winged reptile for millions of years plied the skies, disappeared from the face of the Earth. Dinosaurs-Triceratops, Brontosaurus, allosaurus and many other “saurus”, it is important chestvovali on our planet died out, leaving no trace. As the shark continued to exist.
About 20 million years ago in the sea scoured a huge Stingray, weighing over 100 pounds, and more than 25 different species of sharks, including sharks, reaching 36 meters in length. The length of these monstrous sharks was Opredelenie their huge teeth. Some of the teeth found in California, weighing 340 grams each and reach 15 centimeters in length, and seven – and ten teeth are quite common. They are triangular in shape and closer to the teeth of modern great white sharks that do not exceed 5-6 inches now with a body length of shark of 12 meters (maximum length). These teeth belonged to the ancestor of the modern great white shark the carcharodon, in huge quantities inhabited the seas. When they were first found in the seventeenth-century scientists, naturalists believed that this fossil bird tongues or teeth of serpents. They could not imagine that this shark’s teeth, and ascribed them to the mythical animal. Continue reading
The pond on the site can be a favorite vacation spot. Pond fish is a complex hydraulic structure. What is difficult in General, consists of a number of simple rules. If you apply patience and diligence to make a pond with their own hands for cultivation of fish can any householder on their needs and your taste.
Why you need a pond
The pond is always a decoration of the site, on its edges, you can plant the plants. His presence on site creates a special microclimate.
The opportunity to grow organic fish. In our time – is not unimportant!
Get pleasure from fishing. If there are no natural water bodies, to create conditions useful for the health of the hobby. This can be a family holiday or with friends.
The choice of location
The reservoir should be placed taking into account that till 11 am, he should be well publicized. In the daytime, to 15 hours for pond fits the shade or shade. In warm water are good conditions for development of algae, reducing oxygen for fish.
Deciduous trees should be at some distance from the pond so that the leaves did not litter the pond. The leaves of some trees have harmful effects on fish, it is also possible to transfer aphids on aquatic plants. Continue reading
The sea depths are full of mysteries and inhabited by amazing creatures, which are discussed today.
The largest animal on the planet living in the ocean is the whale. Despite the fact that he is huge, its throat is very small, and the mouth was blocked by Horny plates with fringed edges, which is also called whalebone.
This is baleen for straining food. And eats whale: typing in the jaws of sea water, he filters it through baleen, like a huge sieve.
Water is strained and poured, and small animals – crustaceans and fish, stay inside the pharynx. And though the whale lives in the ocean, he is not a fish – he’s a big marine animal. Female whales feed their young babies with milk, and breathe, the whales, and terrestrial animals – air.
And then there are the toothed whales called sperm whales. They have whalebone is not available, but grow the huge jaws and sharp teeth. The sperm whale dives deep in the sea and get those teeth of an octopus or squid.
Stars are not only high in the sky, but in the depths of the ocean. These stars live, they are called sea stars. Sea stars feed on mollusks. They crawl on the ocean floor, moving their limbs, similar to Lusikisiki and looking for prey. And when you stumble upon a conch shell, grab her with its rays, and peeping through the casement, start to eat the soft contents. Continue reading