Class Bony fish Aquarium fish. Feature
Aquarium fish — ornamental fish . which are contained in the aquariums . Aquarium fish originate from China . The Chinese began to breed aquarium fish since 2000 BC.
For the most part, aquarium fish characterized by bright decorative painting, fancy body shape and small size. The most popular type of aquarium fish are considered to be the gold fish .
To popular aquarium fish include: goldfish . zebrafish . ancistrus . barbs . angelfish . catfish . neon . nannostomus . the Labe . discus . guppies, etc.
Fish – cold-water animals, i.e. their body temperature is close to ambient temperature and does not exceed it by more than 0.5-1 degree (tuna can, the difference can be up to 10 degrees). Therefore, the speed of metabolic processes in fish depends on water temperature. Fish, like any vertebrate animal that has a skeleton, musculature, skin, respiratory system, excretion, reproduction and senses, digestive, circulatory and nervous system.
The movement of fish begin the tail and tail fin that strong kick sent the body of the fish forward. Dorsal and anal fins obespechivaetsya the position of the body. The pectoral fins move the fish body slow swimming, are the wheel and together with ventral and tail fins provide the equilibrium position of the body at his estate. In addition, some fish species can rely on the pectoral fins or move with them on a hard surface. Pelvic fins are mainly a function of balance, but in some species are modified into suction disk that enables the fish to cling to a solid surface.
Blood from the heart enters the ventral aorta, located under the gills. From the aorta depart four pairs of branchial arteries, Gill rise to the petals, where, and branch into capillaries. Here an enrichment of blood oxygen and carbon dioxide.
The digestive system of fish includes the head (mouth, oral cavity and pharynx) and body of the intestine (the rest of the digestive tract, including the esophagus, stomach (not all fish), pyloric appendages, pancreas, liver, gall bladder and intestines).
The nervous system consists of brain, associated with spinal cord and network of nerves. The main function of brain is to receive and interpret electrical signals from different senses – for example, eyes, taste buds, tactile and auditory organs, and to answer them. The brain itself consists of three segments: the forebrain, midbrain and hind brain. Each segment is associated with specific sensory inputs. For example, the hindbrain is associated with taste buds.
The fish skeleton consists of: skull, spine, ribs, fins. The spine form numerous biconcave vertebrae, each of which has two appendages. The spine is divided into two sections — body and tail. The arc of the upper vertebral body of the division are closed, forming the spinal canal where is the spinal cord. The lower arcs of these curved vertebrae joined by a thin, but strong pointed rib guarding Grodno – the abdominal cavity from mechanical impact from the outside.