Main features of natural focality of ixodid tick-borne borrelioses in Russia. P. 177-191.
In a general form the "key" data on natural focality of ixodid tick-borne borrelioses and ecology of their agents — B. burgdorferi s. l. in Russia, which have been accumulated by now, are presented. Vectors and reservoir hosts of different species of Borrelia, as well as a landscape preference of natural foci and ecological factors, determining risk of human infection, are characterized.
in RussianNuclei in the Plasmodium of Intoshia variabili (Orthonectida) as revealed by DAPI staining. P. 192-194.
DAPI staining of wholemounts was used to reveal the parasitic Plasmodium of the orthonectid Intoshia variabili in its host, the turbellarian Macrorhynchus crocea. The nuclei of the parasite differ drastically from those of the host in size, morphology, and the estimated DNA content. Our findings indirectly support the idea that the orthonectid Plasmodium is a distinct parasitic organism, rather than modified host cells.
in RussianComparison of resistance to environmental factors of the molluscs Hydrobia ulvae infected with trematode parthenites and free from infection. P. 195-202.
The influence of trematode infection, mainly with Microphallus claviformis, onto the resistance of mudsnails Hydrobia ulvae to fresh water, desiccation and extremely high temperature has been investigated. It was found out in all variants of experiments that the intensity of mortality in infected individuals is reliably higher than in individuals free of infection. It is suggested, that the negative influence of parasites on the resistance of hosts is related to the disturbance of molluscs' capability to isolate themselves from extremal condition by shutting up the shell with operculum. It is proved by the high rate of salt loss in the infected molluscs in a comparison to non-infected individuals. Our hypothesis based on results obtained and reference data suggests that the rate of trematode parthenites' influence onto the resistance of molluscs depends upon the character of interrelationships in host-parasite systems. Normally, the trematode species having the active cercaria stage in the life cycle show more negative impact onto the resistance of infected molluscs, than those species, larval stages of which develop to metacercaria inside the parthenites.
in RussianDynamics of infection of Bithynia tentaculata (Gastropoda: Prosobranchia) with trematodes. P. 203-218.
The dynamics of infection of Bithynia tentaculata with 7 trematode species was examined during 5 years. Stability of parasite fauna with significant changes of infection rate has been recorded. During the period of observations the infection rate of Sphaeridiotrema globulus, Notocotylus imbricatus, Holostephanus volgensis, Pleurogenoides medians and Metorchis intermedius has decreased, while that of Psilotrema tuberculata has increased. The infection rate of Plagiorchis sp. slightly fluctuated.
It was found out that the infection rate of S. globulus, P. tuberculata, Plagiorchis sp., H. volgensis and M. intermedius increases by the age of hosts. Maximal infection rate of N. imbricatus was observed in mollusks of 2—3 years old.
Based on peculiarities of infection dynamics during the year, 3 groups of parasites have been recognized. 1. S. globulus, P. tuberculata and N. imbricatus show an increase of infection rate from April to August with subsequent decrease. 2. Infection rate of H. volgensis increases during the Summer and reaches maximum in Autumn. Age group of host 2+ and older ones showed some decrease of infection in the beginning of Summer. 3. First cases of infection with M. intermedius occur in May, then the infection rate increases and reaches maximum in the end of July. The infection rate gradually decreases and in the end of October the mollusks infected with M. intermedius are usually absent.
An emission of cercariae is usually observed in June—August. The difference in infection rate of Bithynia tentaculata males and females was not found.
Based on a complex analysis of infection dynamics and population dynamics of mollusks, different aspects of the life cycle of parasites (periods of emission, maturity and longevity of local microhemipopulations) are discussed.
in RussianNew data on trematodes of the families Opecoelidae and Accacoeliidae from fishes in Atlantic Ocean and its seas. P. 219-223.
The additions concerning the morphological characters and measurements of Anomalotrema koiae, Helicometra fasciata, Accacladocoelium macrocotyle, A. petasiporum, and Paraccacladium jamiesoni have been made. Podocotyle atomon (Rud., 1802) in Gaevskaya, Umnova, 1977 described from Sebastes marinus from the northwest Atlantic is considered as Anomalotrema koiae. Helicometra fasciata is found in Mugilidae for the first time. Accacladocoelium macrocotyle and A. petasiporum are found in the new region — the Azores.
in RussianStructure of the copulative apparatus of Sobolevicanthus gracilis (Cestoda: Cyclophyllidea). P. 224-230.
Fine structure of genital atrium, Furman body, distal region of vagina and sac cirrus were investigated. The broad polymorphism of surface microstructures (microtriches) in various parts of copulative apparatus has been revealed. The constitution of prostate glands, being the modified cytons of syncitial epithelium of the intrabursal section of spermaduct wall, is described.
Based on obtained and reference data, a comparative morphological analysis of copulative apparatus organization in lowest and highest cestodes was carried out. The hypothesis suggests that evolution of its organization was connected with the reduction of the muscular elements and simultaneous improvement of their managing, their isolation from surrounding parenchyma and development of supporting connective tissue elements.
It is shown, that Fuhrmann's body has its own developed muscular system armed with power microtriches and being capable to evaginate into the distal region of vagina. It is supposed that S. gracilis obtains of two different ways of copulation in: by means of cirrus that executes the cross fertilization; and by means of the additional copulative formation — Furman body, which guarantees the self fertilization of worms.
in RussianThe parasite fauna of the big and little Baikal oilfishes. P. 231-239.
The parasite fauna of two endemic fish species of the genus Comephorus (Cottoidei: Comephoridae) includes 11 species. Six species were found in Comephorus baicalensis and 9 — in C. dybowskii. Two species only are endemic for Baikal: Myxidium perniciosum and Gyrodactylus comephori. Other 9 species are distributed throughout Palaearctic region. Ecology of parasites and their hosts is briefly discussed.
in RussianThe effect of trematode invasion and chromium sulphate on the crude protein content in the haemolymph of Viviparus viviparus (Mollusca: Gastropoda: Pectinibranchia). P. 240-246.
The combined effect of the trematode infection (Echinoparyphium sp.) and various concentrations of chromium sulphate (0.01, 1, 100 mg/l) onto the crude protein content in the haemolymph of the mollusc Viviparus viviparus was investigated. The normal contents of the crude protein is 0.7— 1.22%. In adult specimens its concentration is 20—80% higher than in molluscs of junior age group. Sex difference by this index, which is higher in females, begins to manifest in four year old individuals only. The contents of crude protein in the haemolymph of pregnant females is 1.5 times higher than in latent ones.
Under the low intensity of the trematode infection, the contents of crude protein in the haemolymph remains normal, while in the case of heavy infection, it decrease 100 times or lower.
In the cases of 0.01—1 mg/l concentrations of chromium sulphate, the content of protein in the haemolymph of V. viviparus decreases, while in the case of 100 mg/l it increases abruptly, in comparison to the norm. The trematode infection intensifies these processes.
in RussianHelminth fauna in small rodents (Mammalia: Rodentia) of channel banks in meliorated territories. P. 247-252.
A helminth fauna of small rodents inhabiting channel banks have been investigated in soil improvement territories (Belorussian Polesie) in the period 1996—1999. 41 helminth species have been found in animals. Generally, there are specific helminths of rodents of the Cricetidae and Muridae families. These animals also participate in life cycles of bird's and carnivore's helminths.
in RussianThe finding of a parasite nematode of the genus Molnaria (Skrjabillanidae) in the Volga Basin. P. 252-254.
A larva of Molnaria sp. has been found in Leuciscus idus caught in the Upper Volga. This is the first record of the nematode of the genus Molnaria in the Volga Basin.
in RussianBook reviews. P. 255-256.
Summary is absent.
in Russian
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