Elemental composition of mushrooms from Gorny Altai

Elemental composition of some species of mushrooms from Ust’-Koksa raion, Gorny Altai, was analyzed to identify species that accumulate the highest concentrations of heavy metals and to estimate the ecological state of the area. The method of X-ray fluorescence analysis using synchrotron radiation was employed.     

New bryozoans from the Devonian of Gorny Altai (Russia)

New bryozoans Saffordotaxis altaicus sp. nov. from the Givetian Stage (Middle Devonian) and Cyphotrypa olgae sp. nov. and Crustopora aliena sp. nov. from the Famennian Stage (Upper Devonian) are described from the Devonian of Gorny Altai.     

Ostracodes from the Tuloi and Karasu formations (Ordovician) of northeastern Gorny Altai

Ostracodes from the Tuloi (Floian, Dapingian and the lower Darriwilian) and Karasu (Darriwilian and Sandbian) formations of the northeastern Gorny Altai are discussed and several ostracode localities are briefly described. Two new species Soanella tuloica sp. nov. and Maraphonia caliginosa sp. nov. are described and figured. The previously described forms are only illustrated.     

Spicules and microspheres in the heliolitid tabulates from the Silurian strata of Gorny Altai,Siberia

Calcareous spicules closely similar to those previously reported in several species of Heliolites, have been found in another heliolitid species, Squameolites junggarensis Lin et Wang, from a clayey limestone of the lower part of Kuimov Formation, of Homerian (Wenlock) age, in the western part of the Gorny Altai, Siberia. The sclerites are associated with ‘microspheres’, identified also in colonies of an unidentified species of Propora. It is suggested that the microspheres associated with the tabulate corals were their photoautotrophic symbionts.     

Some ostracodes from the Gur'yanovka Formation (Upper Ordovician) of northeastern Gorny Altai

Ostracodes from the Gur'yano-ka Formation (Upper Ordo-ician, Sandbian and Katian stages) of Gorny Altai, Russia, are studied for the first time. Some localities with fossil ostracodes of this age are described briefly. Ele-en new species of the genera Ballardina, Eurychilina, Laccochilina, Bolbina, Retiprimites, Pseudozygobolbina, Bullaeferum, Soanella, Egoro-ella, and Allertemmysa are described and figured. The pre-iously described species Leperditella aff. par-ipunctata V. Ivanova, 1959, Grammolomatella valdari V. Ivanova et Melnikova 1977, Longidorsa? baltica Meidla, 1996, and Steusloffina cuneata (Steusloff, 1895) and ostracodes in open nomenclature, Bollia sp., Klimphores sp., Rectella sp., Longiscula sp., are only figured.     

Enhanced blocking capacity of the plague microbe in the body of the flea

During the stay of plague microbe in the organism of flea, under the effect of bactericidal factor increases its ability to form the block of proventriculus in these insects. Thus, in fleas infected on white mice, which were infected in a natural way through blocked individuals, the block of proventriculus appears 2 to 3 times as often (59.5 and 34.0%) as in insects (15.02%) infected on animals, which were infected artificially.     

Distribution and insecticide resistance of the plague flea Xenopsylla cheopis in Maharashtra State, India

Distributions are reported for commensal rat fleas, predominantly Xenopsylla cheopis (Rothschild), in the State of Maharashtra, India, including the city of Bombay, during 1965-80. The X.cheopis flea index was high in most parts of Maharashtra, but low in Bombay. Rattus rattus Linnaeus is the principal host of X.cheopis, but the host range includes Bandicota bengalensis Gray, Golunda ellioti Gray, Mus musculus Linnaeus, Rattus blandfordi Thomas, R. norvegicus Berkenhout, Suncus caerulaeus Lerr, S. murinus Linnaeus and Tatera indica Hardwicke. X.cheopis was found to have high degrees of resistance to DDT, malathion and fenthion, tolerance to gamma HCH (= gamma BCH) but susceptibility to dieldrin. This insecticide resistance situation may contribute to the high flea indices prevailing in the state, with consequent risks of plague outbreaks. Two other species of rat flea, X.astia Rothschild and X.brasiliensis (Baker) were found to be less common than previously recorded. Their apparent replacement by X.cheopis is tentatively attributed, at least partly, to the selective advantage of insecticide resistance in the latter species.     

Cystoporida (Bryozoa) from the Emsian Stage (Lower Devonian) of the Salair Ridge and Gorny and Rudny Altai

Eight bryozoan species of the order Cystoporida are described from the Emsian Stage of the Lower Devonian in the western Altai-Sayan Folded Area. Five of them are new species: Fistulipora salairiensis sp. nov., Fistuliramus fasciculus sp. nov., Fistuliphragma sibirica sp. nov., F. moniliformis sp. nov., and Fistulocladia cincinnata sp. nov. The others belong to the genera Ganiella, Physallidopora, and Fistuliporidra. Most of the cystoporid species studied from the Emsian Stage in the Altai-Sayan Folded Area are widespread laterally. Six cystoporid species have a narrow stratigraphic range and are, therefore, characteristic species of the bryozoan biostratigraphic zones of this region. The species of Physallidopora cantabrica Ernst et Buttler and Fistuliporidra hibera Ernst et Buttler, for the first time encountered in the Emsian of Gorny and Rudny Altai, were previously described from coeval deposits in northwestern Spain.     

Ecological characteristics of flea species relate to their suitability as plague vectors

The ability of vector-borne diseases to persist and spread is closely linked to the ecological characteristics of the vector species they use. Yet there have been no investigations of how species used as vectors by pathogens such as the plague bacterium differ from closely related species that are not used as vectors. The plague bacterium uses mammals as reservoir hosts and fleas as vectors. The ability of different fleas to serve as vectors is assumed to depend on how likely they are to experience gut blockage following bacterial multiplication; the blockage causes fleas to regurgitate blood into a wound and thus inject bacteria into new hosts. Beyond these physiological differences, it is unclear whether there exist fundamental ecological differences between fleas that are effective vectors and those that are not. Here, using a comparative analysis, we identify clear associations between the ability of flea species to transmit plague and their ecological characteristics. First, there is a positive relationship between the abundance of flea species on their hosts and their potential as vectors. Second, although the number of host species exploited by a flea is not associated with its potential as a vector, there is a negative relationship between the ability of fleas to transmit plague and the taxonomic diversity of their host spectrum. This suggests a correlation between some ecological characteristics of fleas and their ability to develop the plague blockage. The plague pathogen thus uses mainly abundant fleas specialized on a narrow taxonomic range of mammals, features that should maximize the persistence of the disease in the face of high flea mortality, and its transmission to suitable hosts only. This previously unrecognized pattern of vector use is of importance for the persistence and transmission of the disease.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at .     

The epizootiological significance of flea accumulation in aggregations of the female long-tailed suslik in the Tuva plague focus

The formation of aggregations of related females is a peculiarity of the intrapopulational organization of long-tailed suslik that results in the accumulation of Citellophilus tesquorum, the main vector and keeper of the plague microbe in the Tuva plague nidus. The plague agent is adapted to the existence on the territory occupied by aggregations of females that manifests itself in the delay of the beginning and prolixity of block-formation periods in fleas. The transfer of the agent from one place to another takes place only at the high abundance of long-tailed suslik. When the number of the suslik is low the plague microbe circulates in the ranges of one or several neighbouring aggregations of females having no possibility for successful transfer to a new place.     

Stomatocysts of chrysophyte algae from bodies of water in territory near Irtysh river in Omsk Region and Lake Teletskoe in Gorny Altai,Russia

The distribution of stomatocysts of chrysophyte algae in the plankton of bodies of water of different types in the basin of the middle reach of the Irtysh (at the Omsk Region), as well as in the plankton and in fouling of the deep-water oligotrophic lake Teletskoe (Gorny Altai) has been considered. The classification of morphotypes of stomatocysts has been carried out. The number of morphotypes found in plankton samples from bodies of water of the middle Irtysh basin is 30 and, in Lake Teletskoe, 60. Four similar morphotypes of cysts were revealed for the bodies of water under investigation.     

Experimental study of the infecting ability of the flea Coptopsylla lamellifer rostrata in the Kyzylkum natural focus of plague

Experimental infecting of the fleas Coptopsylla lamellifer rostrata by plague was carried out. The fleas were infected by feeding through biomembrane (skin of a white mouse) with a mixture of defibrinated blood of guinea-pig and plague microbes. Under concentration 2-3 milliard of the microbes in 1 millilitre, from 60 to 100% of the fleas were infected. Forming of the block of proventriculus was observed in 9-13 day. Mean percent of blocking for all experiments was less than 1%. Maximal rate of blocking (2.8%) was observed in the experiment under everyday 3-hour feeding. After planting of the fleas with blocks on great gerbil (2 fleas on one gerbil) 20% of the gerbils were infected. The conclusion had been made that C. lamellifer rostrata has only insignificant effectiveness as a vector of plague agent in Kyzylkum. Probably it is caused by some specific features of this subspecies.     

Relationship of the flea Citellophilus tesquorum altaicus (Siphonaptera: Ceratophyllidae) with the plague agent

Some aspects of relationships of the flea Citellophilus tesquorum altaicus and bacterium Yersinia pestis of two strains isolated from different parts of the Tuva natural plague focus were studied. Peculiarities of elimination and blood meal activity of fleas infected with two strains of the plague agent were not revealed. Differences in mortality and alimentary activity are considerably determined by the sex of insects. The ability of examined strains to form a proventriculus block was not identical in the strains examined. This ability was expressed higher in the strain I-3428, which originated from the same part of the natural focus as the insectarium flea culture, than in the strain I-3327. During the spring and first half of summer, the proventriculus block appeared more frequently in females. The increasing of the fraction of blocked individuals was observed in both sexes from spring to summer. As for the ability to transmit the plague agent, similar seasonal increasing was noted in males, but in females, the ability to inoculate the plague microbe was always maintained at the same level.     

Seasonal dynamics of infecting ability of the flea Citellophilus tesquorum altaicus in the Tuva natural focus of the plague

The infecting ability of the fleas Citellophilus tesquorum altaicus loff, 1936, the main plague vectors in the Tuva natural focus, was experimentally studied in different periods of the epizootic season. Seasonal dynamics in the efficiency of infecting the long-tailed Siberian souslik with the plague causative agent through flea bites was noticed. Seasonal differences in infectivity of the "blocked" flea bites are revealed. An increase of infected experimental animals with a generalization of infection process in the period of epizooty activation in the natural focus was observed. A resistance of the long-tailed Siberian souslik to the plague agent infection through flea bites in the spring season was registered.     

Paradoxopsyllus scorodumovi (Aphaniptera) flea, an effective vector of plague in a Gorno-Altai natural focus

A study was conducted on the fleas of P. scorodumovi and five local strains of the plague microbe, one of which is typical of the strains of the Altai subspecies and four are non-typical of this nidus. The fleas of this species are capable to transmit not only the plague agent of the strains typical of this nidus but also non-typical ones which differ in some biological properties and are avirulent for most carriers but Pallas's pika. Biological peculiarities of fleas of P. scorodumovi in addition to their high efficiency as vectors of the plague microbe enable us to associate the more active autumn epizooty with fleas of this species.     

The ability of flea species on the common vole from mountainous Dagestan to transmit and preserve the causative agent of plague

The infection ability and terms of preservation of plague microbe in fleas of common vole from Dagestan high-mountain plague focus (Frontopsylla causasica, Megabothris turbidus, Ctenophthalmus intermedius and Amphipsylla rossica) was studied experimentally. Block formation and transmission of the infection by F. caucasica and M. turbidus was observed. The transmission of plague microbe by Ct. intermedius fleas was first carried out. These species of fleas preserve the infection for a long time. Experiments with fleas of A. rossica yielded negative results.     

Pathogenic action of the plague microbe on the flea Xenopsylla cheopis and the ultrastructure of the causative agent at various times of its stay in the vector

Pathology of gastro-intestinal tract of Xenopsylla cheopis fleas infected with plague microbe was determined by means of electron microscopy. Ultrastructure of plague microbe during different periods of its stay in the vector was studied.