Catfish-the Changeling (Synodontis nigriventris)
Prevails in the regions: the basin of the Congo
Body length: 10 cm
Food: carnivorous fish
Habitat: fresh water
Catfish-shifter, or synodontis nigriventris, belongs to the family mochokidae. The homeland of this species is Africa, and to meet him in the natural environment, it is necessary to visit the Congo basin. Shifters reach a length of 10 cm inhabit fresh water and belong to the group of predatory fish.
In Europe the catfish-the shapeshifter first appeared relatively recently – in 1950 in Amsterdam. In our days the activity of this species, both in captivity and in natural conditions, are poorly understood. Continue reading
Seahorse refers to ray-finned fish. Forms a genus in which there are 54 species. They live in shallow waters in tropical and subtropical marine waters worldwide. In the Pacific ocean are found from North to South America. In the Atlantic from Nova Scotia and further South. There is a colony at the mouths of the European rivers. For example, in the Thames. Three species live in the Mediterranean sea.
Body length varies from 1.5 to 35 cm External appearance resembles a chess knight. The skin is thin and stretched bony plates in the form of rings. Each type have their number of rings. The neck is flexible and well expressed. For seahorses is characterized by vertical rather than horizontal movement in the water. They tremble dorsal fin and pectoral fins behind the eyes.
This is the most slow swimming fish in the world. Their top speed is 2-1,5 km/h. Caudal fin not. These bad swimmers most of the time are stationary, hooked prehensile tails for marine vegetation. Snout long and tubular end stigma. It works like a pipette, drawing the food along with water. Eyes have the ability to move, independently from each other. Continue reading
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