Архив выпусков

Parasite fauna of the genus Oncorhynchus in sea was studied and characteristics is given of its peculiarities in the following species of the young: O. kisutch, O. nerka, O. keta, O. gorbusha and O. tschawytscha. Parasite fauna of O. nerka young from the Kurilskoje Lake before the migration and 2—3 months after its stay in sea is analysed.

Crowcrocaecum skrjabini has an intermediate and additional hosts. The mollusk Lithoglyphus naticoides serves as an intermediate host; the invasion extensity is 43.88% in summer and 28.57% — in autumn and winter. In the experiment Gammarus (Rivulogammarus) balcanicus has turned to be an additional host and Carassius auratus gibelio — a definitive hot. The descriptions are given of cercaria (which belongs to a cotylocercal type), metacercaria and marita, reared in the experiment.

A new species of cestodes, Fimbriarioides tadornae sp. n., is described from Tadorna tadorna from the Lake Tengiz (Central Kazakhstan). Artemia salina is an intermediate host of the above cestode. The development of F. tadornae from the oncosphere to the invasional cysticercoid under conditions prevailing in the Lake Tengiz (water salinity of 65‰, average temperature of 22° C) lasts 12 to 13 days.

Hystochemical methods were employed in order to study the distribution of succinic dehydrogenase, glucose-6-phosphat-dehydrogenase, alcaline, acidic phosphatases, lipids, fatty acids, glycogen and neutral, mucopolysaccharides in larvae of three species of cestodes: A. birulai, A. polystictae, A. xemae. A high concentration of succinic dehydrogenase was recorded from the tissue of the tail, scolex and neck. Glycose-6-phosphatdehydrogenase was found in great quantity only in the external parenchyma of the neck of A. polystictae. Here accumulations were observed of lipids which apparently are the products of excretion. The glycogen localization coincides with the distribution of succinis dehydrogenase. The activity of phosphatases is concentrated in the structures of the tail and external membranes of cysticercoids, the acidic phosphatase being dominant. It was concluded that aerobic oxidation dominates in larvae and substances are principally transported through the tail area and excretory aperture.

The description and figures are given of the nematode Paraiotonchium osiris sp. n. parasitic in the body cavity of Musca osiris and in the genital organs of the host females from Turkmenia. Two morphologically different generations of nematodes, gamagenetic and parthenogenetic ones, develop in the body cavitv of the insects. Juvenile females of the gamagenetic generation: n=11; L=474.6 to 587.6; a=15.02 to 22.1; c=5.23 to 6.97; V=(71.5 to 77.7); St—13.0 to 16.1. Mature parasitic females of the gamagenetic generation: n=14; L=1028.3 to 2695.1; a=8.79 to 18.04; c=8.51 to 15.9; V=(76.2 to 84.6); St=21.0 to 27.0. Parasitic females of the parthenogenetic generation: n=7; L=813.6 to 1412.5; a=8.24 to 13.15; c=9.94 to 17.92; V=(88.2 to 91.9); St=14.0 to 16.5. Males: n=30; L=469.2 to 803.8; a=17.0 to 29.12; c=4.5 to 6.99; St=7.5 to 14.0; Sp (d)=18.4 to 23.0; Sp (pr)=34.5 to 41.4; T=(62.41 to 83.57). The new species differs from two other members of the genus Paraiotonchium in the structure of the spicules (a longer distal portion) and a larger bursa in males. A key to the species of the genus Paraiotonchium is given.

Reciprocal hybrids between the stem eelworm of the red clover and those of onion, straw berry, parsnip, parsley and narcissus were obtained. Observations were conducted on the state of hybrid and control populations within 10 generations. A partial genetic and physiologica incompatibility of crossed forms of stem eelworms which manifests itself to a different extent in various combinations of parental pairs, was revealed. The red clover eelworm is a biological race of the collective species Ditylenchus dipsaci, which is at a certain stage of intraspecific differentiation.

Studies of ovogenesis of C. p. molestus at different food regimes (water, sugar, blood) have shown that in winter the imaginal feeding with carbohydrates nearly twice increases the degree of autogenity and fecundity of these mosquitoes. In warm seasons the carbohydratous feeding does not affect the autogenity but increases the fecundity of females and maturation of their ovaries. Poor larval feeding decreases only slightly the autogenity and sharply decreases the fecundity of females. Blood feeding favours the maturation of ovaries in most members of C. p. molestus and the growth of their fecundity.

The analysis is given of the peculiarities of the distribution of the widely spread forest subspecies Heptatoma pellucens pellucens Fabr. in the northern part of its distribution area in Karelia. Some data on the biology of the larva of this subspecies are presented.

After penetrating the skin the first instar larvae spread diffusively and rather evenly in the subcutaneous and intermuscular conncective tissue over the whole body of a deer and do not migrate upwards. The number of larvae in the intermuscular tissue decreases with age and increases in subcutaneous cellulose. During migration their growth varies much that can be partially explained by the heterogeneity of the tissus they advance ahead. On the places of larval localisation a granulomatose inflammation appears with a prevalence of lymphoid cells in the infiltrate and location haemorrhages into surrounding tissues.

Histological studies have shown that in experimentally infected fleas (C. consimilis) Listeria are preserved in the alimentary canal. In infected individuals microbes occur along the whole intestine, from oesophagus to the rectum but most often they are recorded from the mid-gut and proventriculus. Listeria are able to penetrate into the epithelial lining of the mid-gut, can penetrate into its muscular tissue and in some cases enter the body cavity of the insect. The finding of Listeria in the oesophagus confirms the possibility of the transmission of the infection by fleas through the bite without blocking.

The spontaneous infection of Borrelia latyshevi population of Ornithodoros tartakovskyi and its hosts in the foothill zone of southern Tadjikistan was studied. A great part of the Horsfield's terrapin unsusceptible to the spirochaete in the feeding of the tick's population was established. The foci is apparently maintained on account of the rising number of the red-tailed Libyan jird. In years of the depression of rodents number the main part in the preservation of the infection belongs to the ticks.

In birds of the order Ralliformes inhabiting the southwestern part of the Caspian Sea there were found four species of mites of the family Rhinonyssidae, parasites of the nasal cavity: Sternostoma fulicae Fain et Bafort and Rallinyssus caudistigmus Strandtmann in Fulica atra L., R. caspicus sp. n. in Gallinula chloropus (L.), R. gallinulae Fain in Porphyria polyocephalus (Lath.).

Experimental infection of males and females of Phlebotomus papatasi Sc. with Leishmania tropica major from man and L. gimnodactyli from Agama sanguinolenta was carried out in order to obtain mixed infection. Sand flies from the laboratory culture were successivejy infected with promastigotes of each species of Leishmania by means of compulsory dose feeding according to Alekseev's method. For identification of Leishmania cultures isolated from experimentally infected sand flies Alder's serological test modified by Safjanova was used. The mixed infection was obtained both in males and females of sand flies. The success of modelling of mixed infection depends on the succession of the administration of studied strains of Leishmania. It depends as well on the interval between infected feedings. The dependence of the experimental results on the number of promastigotes administered into the intestine of sand flies was not recorded.

Studies of the contents of total, albuminous and residual nitrogen in the liver tissue of chickens at a single and 3-fold infection with 100 000 oocysts of E. tenella were undertaken. It was established that a single infection of 20-, 40- and 60-day old chickens is accompanied by a decrease in the contents of total and albuminous and an increase in the residual nitrogen. Their level is restored as a rule by the 20-th day after infection. In 40-day old chickens by the 20-th day after the 2-nd and 3-d infections, in contrast to non-immunized chickens the level of total and albuminous nitrogen increases. Residual nitrogen concentration remains in the standard ranges.

A new technique is given of the absolute calculation of parasitic Protozoa in fishes. The mucus from the body and gills of fishes was mixed with such volume of water (V) that the drop of mixture (v) was clearly seen under the microscope. The calculation of Protozoa was done in a sample from three drops of mixture covered with three slides (S). From 50 to 100 viewing fields were seen the them and an average number of Protozoa in one field was calculated. The total number of Protozoa in one fish (N) was equal to an average number of parasites in a viewing field (n) multiplied by the total number of viewing fields (m) which could be obtained at the examination of the whole mixture. The latter was calculated conventionally (V/v •S/s) where s — a square of a viewing field. Thus, N= (V/v •S/s) (nk±tσ) where the error σ

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Summary is absent.