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
Poisonous fish on the planet much more than poisonous snakes – more than 1250 species (snakes – 410). And every year ichthyologists discover new dangerous species. In this article we are not talking about the exotic inhabitants of the tropical seas, and about ordinary Russian fish living in our rivers. That’s only when you try to use this trivial-looking production in food from fisherman might suddenly begin diarrhea, headache, hallucinations, and other troubles, including death.
Easy Russian fish
Let us first clarify what classes can be divided poisonous fish. So, they are primary and secondary toxic-poisonous. What does it mean? That means there are fish, like snakes produce venom in special glands or by its nature containing in the body dangerous products of metabolism, that is, initially-poisonous.
To secondary poisonous fish are able to accumulate in their bodies a poison contained in the environment. Such environments can be living in the pond poisonous algae or, even worse, fall into the water of toxic human waste.
And if the second paragraph is all clear, and to protect yourself from poisoning very easily (just not enough to catch and certainly not to eat fish caught in suspicious ponds), initially-poisonous things are much more complicated. We begin our story. Continue reading
The history of breeding goldfish Asia has at least a Millennium and originated from children’s hobby to collecting. in which the housing was offered and developed in cages. in the paddocks. in the wells. in tubs and barrels for all small and medium animals — as the first kind of Pets at home .
In China and Korea over a thousand years ago was engaged in not only fishing. but breeding and raising goldfish. Over the years of breeding the Chinese fish farmers. appeared and established natural mutations with drastic changes in body shape and fin structure. eyes. the structure of the skin and staining fish were obtained decorative forms and color variations, which became the core of most of today’s known species.
The first written mention of the Golden fish with red scales came from China during the reign of the Qing dynasty ( 265 -420 ad ). In those days, these fish were seen in one of the lakes of mount Lushan. the area of the river the City is near the modern province of Shaanxi. which flows to the South China and Northern Vietnam.  In the ancient Chinese treatise Shan Hai Jing. presumably written in the late centuries BC — the beginning of our, there is also a record of the “red carp”. However, there is absolutely no certainty that these wild representatives were the ancestors of segodnyashnaya fish. It is assumed that the red coloration was obtained as a result of purposeful breeding work first pet lovers and falls on the reign of the Tang dynasty ( 618 -907 year of a new era ). 
It is possible that the appearance of unusual forms and colors of goldfish had a direct influence of the religious community professing Buddhism. manifestation of pity and humanity to the poor, while maintaining the ugly offspring of pond fish in specially equipped farms and dams, and then in specially created containers and decorative vessels; not taking them for food. Continue reading