Marine fish actively drink sea salt water, providing the necessary level of water for normal functioning, and excess salt is removed from the body. The exchange of chlorine ions, sodium, potassium between the organism and the environment both in freshwater and marine fishes occurs through special chloride cells located in the gills, but in freshwater they are used to remove metal ions from water, and at sea to remove them from the body. This process is connected with energy expenditure, as occurs against the gradient. Energy is provided by the involvement of sodium and potassium. “Gill pump” that creates the possibility of a permanent replenishment of salts in freshwater fish, has high efficiency and is able to extract sodium and chloride ions from water millimolar and even lower concentration. Table salt since ancient times used in feed for fish as a preservative, to increase the appetite of fish, improve the absorbability, promote growth, and juvenile anadromous fish in which to prepare for the marine period of life. Due to the active exchange of sodium and chlorine with the environment, their constant intake of fish and disposal along with a large volume of liquid fish not afraid of high content of sodium chloride in the feed. Continue reading
In the seas and oceans live the most unusual and alien beings on Earth. And some of them look very scary…
Fish-frog. Found in the Atlantic, Indian and Pacific oceans on muddy or sandy bottom, sometimes burrowing into his eyes. Some members of the family Zapovednaya fish have poisonous spines and are dangerous for swimmers.
This beauty’s name is fish-drop, and it lives only in Australia. Deep-sea benthic fish of the family psychrolutidae, which because of its unattractive appearance often referred to as one of the most bizarre ocean deep-water fish on the planet. The structure of the anterior part of the head gives the impression that the fish are constantly frowns and is unhappy “facial expression” what the fish takes the first place in the rankings of the most bizarre creatures in surveys on the Internet. Continue reading
Catfish — fish–giant. It is the largest predator that lives in fresh water. Belongs to the family somovyh. Representatives of this family are peculiar to the clumsy, highly elongated, spindle-shaped body, naked or covered with bony plates. The head is relatively large, tapered. Mouth wide, with numerous small teeth having the shape of a cone.
To this family belongs more than 550 species that live in fresh waters. Most likes deep standing water and is muddy. Catfish hunt, lying on the bottom motionless waiting for prey.
In reservoirs of Russia, the spread of ordinary som. It sometimes reaches a length of 3 m, weight 300 kg. Scientists believe that these giants are about 80-100 years, but most caught catfish weighing 10-20 kg. Their body is covered with a thick layer of mucus, the skin is dark with a greenish tint. Continue reading