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ANATOMY of FISHES
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choronomic constitution of fishes is complex and is various. Basically, each frame
of an organism ensures his adaptation to concrete conditions of a habitation.
However some signs are peculiar to the majority of fishes, for example spinal,
pelvic, tail, pectoral and abdominal flippers. Alimentiry system. On an intrinsic constitution the fishes are similar to others backboned. The body double-sided is symmetric, short of a digestive tube. Last consists of a mouth, jows usually obtected with dens, tongue, drinks, esophagus, stomach(ventriculus), intestine, polioriches of appendages, liver, pancreas, lien, direct, or thick, intestine and anal, or pelvic, foramen. In an intestine of sharks and some other primitive fishes there is a spiral valve, unique member increasing "«worker" a surface of a digestive tube without augmentation of his(its) length. At predatory fishes an intestine usually short, forming one - two loop, while at feeding green of kinds it(he) long, gyrose, with a set of loops. The
breathing system consists from branchiate of arcs coated(obtected)
tender fleshy branchiate with petals, abundantly supplied by blood on capillars
and larger pots. In a foremost part of a mouth the special oral valves handicapping
an anatropic output(exit) of water are located. When the mouth is closed, she(it)
gets in a drink, streams between branchiate by arcs, washes against branchiate
petals and leaves outside through branchial apertures (at cartilaginous fishes)
or foramen under branchiate by a cover (at osteal fishes). The nervous system - brain, nerves and sense bodys - introduces functions of an organism and binds it(him) to the choronomic world. As well as at others backboned, in nervous system of fishes enter head and spinal cord. Head consists from olfactory by a lobe, hemispheres of a neoncephalon, diencephalon with a pituitary body, visual lobes (average brain), cerebellum and myelencephalon. |
From these departments ten cranial nerves head out. The eye consists of a cornea, lens, iridescent shell, retina, and the sharks have still eyelid-winking membrane, which can approach from below on a cornea. The outside ear at fishes is absent. The intrinsic ear consists of three semicircular of canals with ampulas, oval sack and circular мешочка with a flange (lagene). Fishes - unique(sole) backboned with two or three steams(vapours) of otoliths, or auralpebble, which help to sustain the defined position in space. At some bunches swimming the bladder intercommunicates with an intrinsic ear with most thin tube, and at minnows, carpes, catfishes, harazines and electrical eels is connected(linked) to it(him) by the complex(multiple) osteal gear - veber by the device. It allows better to accept («to "hear") vibrations of environment. System of a lateral line - unique sense body of fishes. Usually she(it) represents a network of excavations or canals in a skin of a head and trunk with the nervous terminals in depth. These canals at osteal fishes usually open on a surface by pores. All system is bridged by nerves to an intrinsic ear. She(it) serves for perception of low-frequency fluctuatings, that allows to discover driven entities.
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Anatomical acclimatizations. The fishes are extremely various on a constitution and acclimatizations. They go, float and fly (plan). Some are capable to see both in water, and in air to emit various notes to radiate light and even to generate a strong electrical charge. Each frame fulfills the assignment - serves for protection, acquisition of nutrition or breeding.
Mouth, jows and dens. The jows of fishes are various - from toothless up to supplied chisel-figurative by cutters and long sharp canines. At some feeding green of the forms, for example of fishes - surgeons and south american of catfishes, the dens are on long thin pedicel with calyx by fastigium. The fishes - parrots are remarkable by the dens, forming a bill, that adds them resemblance to auks, whence there was a title of family. The mouth can be directed downwards, as at sharks, forward, as at the salmons, or upwards, as at astrologer. The lips are coated(obtected) long capilliform excrescence(offshoot), as at hair-tooth (Trichodon), which, having dug in a soil, through this filter clears inhaled water of sand. Branchiate of a foramen are be of two phylums. Five outside branchial apertures are typical of sharks and slopes, and for osteal fishes - four or five foramens covered branchiate with a cover, which directs push through gills water to one general(common) discovering outside cleft(rima).
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Eye. In the whole eye at fishes are arranged the same as and at others backboned. Outside they are coated(obtected) with a cornea. Light passes through a pupil - a foramen in an iridescent shell - and is focused orbicular lens on a retina borrowing(occupying) a back head of an eye. The visual stimulants are transferred from a retina on an optic nerve in a brain. As at a retina the fishes have also rods, and retort, it is possible to conclude, that they distinguish colours. At quadri-eyes (Anableps), dwelling(living) in Central and Austral America, eye are shared into two parts: upper is fitted to see in air, and inferior - underwater. Lens here oval also is located under such angle to focus on a retina light beams from both sources. As the osteal fishes are deprived century for humidification an eye during stay in air, quadri-eyes decides(solves) this problem, periodically dipping a head in water.
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