BLOODSUCKERS (Hirudinea) — the class like annlides (Annelides) which is subdivided into ancient Archihinidinea subclass with two types and the real Euhirudinea subclass. The real P. combine hemipterous Rhynchobdella group with two families (flat P. and fish P.) and beskhobotny Arhynchobdella group with two families (maxillary P. and pharyngeal P.). In total on the globe is apprx. 400 types of P., in the USSR — apprx. 80 types. The blood-sicking maxillary and nek-ry flat P. sucking blood of the person are widespread preferential in subtropical and tropical zones where can do considerable harm to people, and also domestic mammals (see. Girudinoz ).
The majority of types of P. lives in fresh reservoirs, it is much less — in the seas (from this. fish P.); a small amount of maxillary and pharyngeal P. leads a land life — in the soil, on plants (as a rule, in wet tropical and subtropical zones). Length of a body can reach 150 mm. The body more often flattened, is more rare cylindrical, as a rule, dense, greenish, brown or black coloring; it consists of 33 segments (or somites) and the head blade merging with front segments. There are two suckers — circumoral and back. C. to N of page it is presented by head nodes, subpharyngeal weight, nodes of a belly chain and back weight; nodes are well developed, nervous cells of the large size. The real blood vessels at the majority of types of P. are reduced and replaced with the cavities formed of the remains of a secondary perigastrium (tselom). Gas exchange is carried out through skin. The secretory system is presented by the metansfridiya deprived of funnels. A structure of the alimentary system variously depending on character of food: blood-sicking P. have a trunk or jaws serving for a prokusyvaniye of skin in a middle part of the digestive device — shoots in which the exhausted blood collects; at predatory bloodsuckers (separate species of maxillary bloodsuckers and pharyngeal bloodsuckers) jaws are strongly reduced or reduced, shoots for the exhausted blood are absent.
Reproduction at P. only sexual. All P. — hermaphrodites, the sexual device difficult, fertilization internal, lay eggs in cocoons of the different device. Development direct.
In the territory of the USSR only two look blood-sicking maxillary P. lives: the medical Hirudo medicinalis and the Nile P. which is usually called horse (Limnatis nilotica, L. turkestanica). Medical P. are widespread in the basic in Ukraine, the Caucasus and in Central Asia. As a result of injurious fishing medical P.' number in nature was strongly reduced; they are parted in simulated conditions by a technique of the prof. G. G. Shchegolev and his employees at biofactory near Moscow. The Nile P. live in Transcaucasia and Central Asia in low-flowing reservoirs. At drink of a raw water they get to an oral cavity, a throat, a throat where are attached, suck blood and can cause considerable bleeding, and in certain cases and suffocation. Sometimes confuse predatory maxillary P. to the Nile P. — so-called big lozhnokonsky Haemopis sanguisuga which does not suck blood, and entirely swallows different invertebrates or parts of their body (tsvetn. fig. 1 — 6). Considerable harm to fishery is done by P. parasitizing on valuable breeds of fishes (Acanthobdella peledina — on salmon, Piscicola geometra — on cyprinid etc.). Also nek-ry types of P. of the sort Proto-clepsis-Theromyzron sucking blood at waterfowl and capable to cause their mass death are harmful.
The clinical use of bloodsuckers
Treatment by means of P. — a girudoterapiya, or a delloterapiya — is known since ancient times, but it gained especially broad development along with use of bloodletting to the 18 and first half of 19 century at the end. The mechanism of action of work therapy is connected by hl. obr. with secretion by bloodsuckers at a krovososaniye hirudine (see), possessing anti-coagulating action.
Indications and Contraindications
are applied by P. according to strict indications, is preferential at some forms of heart failure and vascular diseases, for the purpose of a krovoizvlecheniye, usually local and as a revulsive. Girudoterapiya is used by hl. obr. at a cerebral form of arterial hypertension, predynsultny states, at the phenomena of local stagnation, at inflammatory processes in blood vessels, female generative organs, etc., at the congestive liver most often observed at mitral heart disease, at right ventricular insufficiency, stenocardia and a myocardial infarction. P.'s use at vein thromboses, thrombophlebitises and hemorrhoids reduces puffiness of fabrics and gives some antitrombotichesky effect.
Contraindications to P.'s use are the diseases which are followed by bleeding in connection with the lowered coagulability of blood and also hemolysis of various genesis, an anemia, sharp exhaustion. It must be kept in mind that saliva P. is in certain cases capable to cause inflammatory processes on skin of the person (see. Dermatozoonoses ).
Technology of use
On skin in the field of body which want to influence (heart, a liver etc.) put from 4 to 12, about 20 bloodsuckers are rare. At some neurologic diseases of P. put in the field of a mastoid or to a nape (a back surface of a neck). Sometimes at the same time several bloodsuckers (4 — 6) put to a tailbone. It is impossible to put P. on places where vessels pass under the skin since P. can bite through also a vascular wall.
Leather is previously carefully processed without use of odorous substances; it cannot be washed soap, to grease with iodine, to wipe with ether, etc. Skin if it is necessary, shave, wipe with alcohol to cause a hyperemia, and then wash warm sterile water and wipe dry cotton wool. Items shall be hungry (thin, quickly to move), otherwise they are not fit for the use. For P.'s involvement skin can be moistened with sugar water. Items take fingers about the head, to-ruyu put to skin, and wait until P. sticks, then put following. Sometimes P. is put in a test tube the head by the output end, densely put a test tube to skin and waited until P. sticks. If P. quickly disappears, on its place it is necessary to put another. It is possible to put P. from a glass glass. That P. did not creep away, tweezers with cotton wool direct them to the right place. Each P. in 0,5 — 1 hour nasasyvat 10 — 15 ml of blood and disappears. If P. long time itself does not disappear, on it it is necessary to strew salt or to moisten it with a salt water. It is impossible to tear off P. Sometimes after P.'s separation from skin blood long exudes from a wound. In this case apply a sterile bandage a wound, and if necessary a pressure compressing bandage. Sometimes it is necessary to sew up wounds or to impose on them brackets.
Bibliography: Lukin B. I. Bloodsuckers, in book: Fauna of the USSR, under the editorship of B. E. Bykhovsky, t. 1, L., 1976; M. V Blue. Observations over cultivation of medical bloodsuckers, Zool, zhurn., t. 23, No. 6, page 293, 1944; Shchegolev G. G. and Fedorova M. S. Medical bloodsucker and her use, M., 1955.
E. I. Lukin; V. I. Kristman (wedge, use).