scholarly journals Исследование влияния паводков и некоторых биотических факторов на распространение моллюсков семейства Bithyniidae

2019 ◽  
Vol 11 (1) ◽  
pp. 5
Author(s):  
А.С. Маюрова ◽  
М.А. Кустикова
Keyword(s):  
Water Pollution ◽  
Population Density ◽  
Indigenous People ◽  
Intermediate Hosts ◽  
Opisthorchis Felineus ◽  
Pollutant Concentrations ◽  
Study Sites ◽  
Khanty Mansi Autonomous

The dependence of population density of Bithyniidae snails, which are the first intermediate hosts of Opisthorchis felineus (cat fluke), on maximum flood levels, pollutant concentrations, and the presence of leeches was investigated in water basins of the Khanty-Mansi Autonomous Area. Study sites were at the rivers Ob (Surgut environ), Irtysh (Khanty-Mansiysk environ) and Bolshoy Yugan (Ugut village). The prevalence of the mollusk was shown to correlate positively with flood levels and negatively with water pollution and the presence of leeches that feed on snails. These observations may be useful for planning measures aimed to control opisthorchiasis in indigenous people that consume fish infected with opistorchis flukes.

scholarly journals Features of the first intermediary host distribution of Opisthorchis felineus near the major cities of KhMAO–Ugra (Western Siberia)

2019 ◽  
Vol 9 (4) ◽  
pp. 481-501
Author(s):  
Aleksandra Maiurova ◽  
Marina Kustikova
Keyword(s):  
Population Density ◽  
Western Siberia ◽  
Hydrological Regime ◽  
Opisthorchis Felineus ◽  
Ob River ◽  
Host Distribution ◽  
Bithynia Tentaculata ◽  
Irtysh River ◽  
Khanty Mansi Autonomous ◽  
The Irtysh River

In this paper the dynamics of invasion extensiveness of freshwater Bithyniidae snails by trematodes Opisthorchis felineus (cat fluke) in the waters of Khanty-Mansi Autonomous Area was determined. The study was conducted for the Ob river (Surgut) and the Irtysh river (Khanty-Mansiysk) for 7 years. As a result of the study, it was determined that the population density of snails and the extensiveness of their invasion by O. felineus trematodes are higher in the Irtysh River, which is associated with the hydrological regime of the river. Indicators of invasion extensiveness are higher for Bithynia tentaculata snails than Bithynia troscheli.

scholarly journals Distribution and Habitat Preference of Hispid Hare (Caprolagus Hispidus) In Shuklaphanta National Park, Nepal

2017 ◽  
Vol 31 (1-2) ◽  
pp. 1-16
Author(s):  
Dhirendra Bahadur Chand ◽  
Laxman Khanal ◽  
Mukesh Kumar Chalise
Keyword(s):  
Population Density ◽  
National Park ◽  
Imperata Cylindrica ◽  
Grass Species ◽  
Population Status ◽  
Tall Grass ◽  
The Past ◽  
Wide Range ◽  
Food Species ◽  
Study Sites

 Hispid hare (Caprolagu shispidus) is an endangered lagomorph which had a wide range of distribution in the past, but currently it is known to occur only from few isolated tall grass pockets of India and Nepal. We explored the population status, habitat utilization and existing threats of the Hispid hare at Shuklaphanta National Park (SNP) by the strip transect and quadrate sampling methods from November 2015 to May 2016 covering both winter and summer seasons. Four study sites of total 1.58ha were selected within SNPand strip transects were randomly laid to determine presence and absence of pellets of Hispid hare and their counts were used to estimate the population density. The Population density of Hispid hare was found to be 0.1820/ha in winter and 0.2268/ha in summer with the statistically significant preference to the tall grassland habitat. Twelve grass species were identified in the habitat of Hispid hare with dominancy of Saccharum spontaneum, Imperata cylindrica, Narenga porphyrocoma, and Saccharum munj. Among the grasses, Imperata cylindrica and Narenga porphyrocoma were the food species of higher preference for Hispid hare.

scholarly journals Population structure of Opisthorchis felineus (Trematoda) and its second intermediate hosts — cyprinid fishes in the Ob-Irtysh focus of opisthorchiasis, based on allozyme data

2014 ◽  
Vol 51 (4) ◽  
pp. 309-317 ◽  
Author(s):  
O. Zhigileva ◽  
V. Ozhireľev ◽  
T. Stepanova ◽  
T. Moiseenko
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Allozyme Variation ◽  
Intermediate Hosts ◽  
Opisthorchis Felineus ◽  
Cyprinid Fishes ◽  
Low Levels

AbstractGenetic variability of West Siberian populations of Opisthorchis felineus and two species of cyprinid fish, its second intermediate hosts, was studied by isozyme analysis. Low levels of allozyme variation and genetic differentiation in O. felineus from the Ob-Irtysh focus of opisthorchiasis were detected. The proportion of polymorphic loci was 21.1 %, the average observed heterozygosity (Hobs) was 0.008, and expected heterozygosity (Hexp) was 0.052. For most loci in O. felineus deficit of heterozygotes (FIS = 0.7424) was observed. A comparison of population genetic structure of fish and parasites showed they were not congruent. Estimates of genetic differentiation of the parasite were smaller than for the fish — its intermediate host. Migration and population structure of the second intermediate hosts do not play an important role in formation of the population-genetic structure of O. felineus in the Ob-Irtysh focus of opisthorchiasis.

scholarly journals Wind and insect pollination (ambophily) of Mallotus spp. (Euphorbiaceae) in tropical and temperate forests

2013 ◽  
Vol 61 (1) ◽  
pp. 60 ◽  
Author(s):  
Eri Yamasaki ◽  
Shoko Sakai
Keyword(s):  
Population Density ◽  
Temperate Forest ◽  
Fruit Set ◽  
Forest Succession ◽  
Airborne Pollen ◽  
Flowering Plants ◽  
Insect Pollination ◽  
Pioneer Tree ◽  
Pioneer Plants ◽  
Study Sites

Relatively few flowering plants show ambophily (pollination by both wind and insects), and whether and when ambophily is advantageous has not been studied well. In the present study, we report ambophily in two dioecious pioneer tree species, Mallotus japonicus Müll.Arg. in a temperate forest of Japan, and Mallotus wrayi King ex Hook.f. in a tropical forest of Borneo, and discuss the conditions that contribute to the maintenance of ambophily. Both species are pollinated by wind because they set fruits even when flower visitors were excluded and because substantial amounts of airborne pollen reached female trees. Insects may also contribute to fruit set, because insects with body pollen visited female inflorescences. Because M. japonicus and M. wrayi exhibit floral characteristics that are adapted to both wind and insect pollination, ambophily may be actively maintained in the two species at the study sites and perhaps elsewhere. Whereas previous studies have indicated that ambophily is advantageous for pioneer plants because of changing wind conditions during forest succession, our preliminary data suggest that changes in population density also contribute to the maintenance of ambophily in M. japonicus.

scholarly journals Aedes albopictus (Skuse) susceptibility status to agrochemical-insecticides used in durian plantating systems in southern Thailand

2020 ◽  
Author(s):  
Sakda Ratisupakorn ◽  
Sokchan Lorn ◽  
Nsa Dada ◽  
Aran Ngampongsai ◽  
Pawit Chaivisit ◽  
...  
Keyword(s):  
Population Density ◽  
Aedes Albopictus ◽  
Insect Pests ◽  
Field Application ◽  
Insecticide Susceptibility ◽  
Future Studies ◽  
Lambda Cyhalothrin ◽  
Southern Thailand ◽  
Study Sites ◽  
Susceptibility Status

ABSTRACTHigh rates of dengue, chikungunya, and zika morbidity occur in southern Thailand. The intensive application of insecticides in orchards could impact not only agricultural insect pests, but also non-target insects, such as mosquitoes, or non-target beneficial insects. In this study, the population density and insecticide susceptibility of Aedes albopictus populations to field application concentrations of four agrochemical insecticides – cypermethrin, chlorpyrifos, carbaryl, and imidacloprid were examined. Mosquito eggs were collected from durian cultivation sites in five provinces in southern Thailand and hatched and allowed to develop to the adult stage. The study sites were categorized into three groups based on insecticide application; intensive-application of insecticides (IA), less-application of insecticides (LA), and no application of insecticides (NA). Twenty ovitraps were deployed for at least three consecutive days at each study site to collect mosquito eggs and to determine the Ae. albopictus population density then WHO tube assays being used to determine the susceptibility of adult mosquitoes to selected insecticides. This study represents the first report of the agrochemical insecticide susceptibility status of Ae. albopictus collected from durian orchards in southern Thailand. The study found that the populations of Ae. albopictus were susceptible to chlorpyrifos, but showed reduced mortality following exposure to lambda-cyhalothrin, carbaryl, and imidacloprid which is suggestive of the existence of resistance. These findings provide new insights into mosquito insecticide resistance focusing on Ae. albopictus populations and has important implications for mosquito and mosquito-borne disease control in Thailand as well as providing baseline data on which future studies can develop.

scholarly journals Population Density, Habitat Characteristics and Preferences of Red Fox (Vulpes vulpes) in Chakwal, Pakistan

2020 ◽  
Vol 7 (4) ◽  
pp. 74-83
Author(s):  
AMIR NASEER ◽  
MUHAMMAD BILAL ◽  
UMAR NASEER ◽  
NAUREEN MUSTAFA ◽  
BUSHRA ALLAH RAKHA
Keyword(s):  
Population Density ◽  
Vulpes Vulpes ◽  
Red Fox ◽  
Estimation Method ◽  
Habitat Destruction ◽  
Habitat Characteristics ◽  
Line Transect ◽  
Importance Value Index ◽  
Preferred Habitat ◽  
Study Sites

The Red fox (Vulpes vulpes) is a least concern carnivore according to the IUCN Red List of Threatened Species (2016). However, in Pakistan Red fox is considered as Near Threatened (NT), due to habitat destruction and depletion of food resources. The objective of the study was to identify habitat preferences and population density of Red fox in District Chakwal, Pakistan. Line transect census method was used to estimate the population density of Red fox through direct sighting and indirect method of burrow counting, presence of footprints and scats. A total of 10 transects were carried out at three potential sites: Devi, Photaki and Chumbisurla Wildlife Sanctuary (CWS) in Chakwal based on preliminary surveys. Habitat preference was estimated by comparing three different study sites by quadrat method and found that CWS area is preferred habitat for Red fox. A total of 24 plant species were recorded in the study areas, among them Cynodon dactylon is major herb found to provide shelter to Red fox in all study sites based on Importance value Index (I.V.I) at CWS (IVI=208.8) followed by Devi (IVI=185.93) and Photaki (IVI=142.33). The maximum population density of Red fox through direct sighting at CWS having 0.26 individuals/km2 compared to Devi and Photaki having 0.16 and 0.13 individuals/km2, respectively. The indirect estimation method revealed that maximum dens were found in CWS area compared to Devi and Photaki, while footprints and scats were found maximum in Devi and Photaki, respectively. It is concluded that Red fox preferred habitat is CWS site. Habitat destruction and conflicts with fox are causing the population of the Red fox to dwindle in Chakwal, Pakistan.

Cercariae Opisthorchis felineus and Metorchis bilis from first intermediate hosts for the first time in basin of Chany lake (Novosibirsk region, Russia) is found

2016 ◽  
Vol 3 (3) ◽  
pp. 421-429 ◽  
Author(s):  
Сербина ◽  
E. Serbina
Keyword(s):  
Human Health ◽  
Western Siberia ◽  
Intermediate Hosts ◽  
Double Infection ◽  
Host Snail ◽  
Opisthorchis Felineus ◽  
Novosibirsk Region ◽  
Lake Systems ◽  
First Time

Objective of research: to perform the analysis of long-term (15 annum) dynamics of Bithyniidae snails infected by trematode parthenites from the Chany Lake, the biggest lake in the south of Western Siberia. Materials and methods: The Bithyniidae snails examined in the lake-river systems Chany Lake in 1994-2013 (in the middle reaches and in the estuary of the Kargat River) and in the Zolotye Rossypi Bay and the Malye Chany Lake. The Bithyniidae snails were collected from May to September (twice in any ten days) by hand from 4–6 plots of 0.25 m2 at a depth of 0.1–0.7 m. In total, 8,316 Bithynia troscheli (Paasch, 1842) and 766 В. tentaculata (L., 1758) were examined. Identification of parthenitae trematode was based on observation when mature cercariae were capable of leaving the shell of the host snail on their own. Results and discussion: In Bithyniidae snails, we found parthenites from trematodes from 12 families Cyathocotylidae Mühling, 1898 Poche, 1925; Prosthоgonimidae Luhe, 1909; Pleurogenetidae Looss, 1898; Lecithodendriidae Odhner, 1911; Microphallidae (Ward, 1901) Travassos, 1920; Plagiorchiidae Lühe, 1901 Echinostomatidae (Looss 1899) Dietz, 1909 Odhner 1910); Psilostomidae (Looss 1900) Odhner 1913; Notocotylidae Luhe, 1909; Monorchiidae Odhner, 1911; Cyclocoelidae Kossack, 1911 и Opisthorchidae (Lass, 1899) Braun, 1901. The prevalence of bithyniid snails infected by trematode parthenites varied from 1,6% to 24,1% in different years The double infection by trematode parthenites was found in 0,96% bithyniid snails from estuary of the Kargat River; 4,45% in the Malye Chany Lake, and 26,6%, in the Zolotye Rossypi Bay. The cercariae of Opisthorchidae family in four annum of the fifteen detected. The prevalence of bithyniid snails infected by trematode parthenites from Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890) was observed in Chany Lake systems for the first time. Both species (O. felineus and M. bilis) of trematodes have danger to human health and causes very dangerous disease, opisthorchiasis and metorchiasis.

Populations of Acanthocephalus anguillae and Pomphorhynchus laevis in rivers with different pollution levels

1998 ◽  
Vol 72 (4) ◽  
pp. 331-335 ◽  
Author(s):  
P. Galli ◽  
L. Mariniello ◽  
G. Crosa ◽  
M. Ortis ◽  
A. Occhipinti Ambrogi ◽  
...  
Keyword(s):  
Water Pollution ◽  
Negative Binomial ◽  
Asellus Aquaticus ◽  
Intermediate Hosts ◽  
Pomphorhynchus Laevis ◽  
Pollution Levels ◽  
Polluted Sites ◽  
Different Levels ◽  
Leuciscus Cephalus

AbstractThe distribution of two acanthocephalan species (Pomphorhynchus laevis and Acanthocephalus anguillae) in the chub (Leuciscus cephalus) was studied in foriver reaches characterized by different levels of pollution: the River Ticino ne Abbiategrasso (unpolluted), the Naviglio Grande Canal, in Milano (slightly polluted), the River Lambro near Merone village (polluted) and the Riv Lambro near Monza (severely polluted).Pomphorhynchus laevis was restricted to the unpolluted and the slight polluted sites, while the intensity of A. anguillae increased proportionally water pollution. These differences were partially explained by the variation in abundance of their intermediate hosts (Echinogammarus stammeri for P. lavis and Asellus aquaticus for A. anguillae). Data on the occurrence of P. laevis at A. anguillae showed a significant negative binomial frequency distributic suggesting their tendency to be aggregated within the host populations L. cephalus.

scholarly journals Cluster and correlation analyses of the chemical composition of groundwater nearby MSW landfills

2019 ◽  
Vol 135 ◽  
pp. 01015
Author(s):  
Alexander Nevzorov ◽  
Mikhail Slesarev ◽  
Alexey Korshunov
Keyword(s):  
Chemical Composition ◽  
Population Density ◽  
Transport Infrastructure ◽  
Water Sampling ◽  
European North ◽  
Correlation Analyses ◽  
Pollutant Concentrations ◽  
Marker Substances ◽  
The World ◽  
And Storage

In areas of the European North with a low population density and poorly developed transport infrastructure, it is difficult to organize waste removal and storage at large landfills, therefore many settlements have small landfills of municipal solid waste (MSW), and the practice of placing them in swamps is very common, which leads to the migration of pollutants into adjacent rivers. Environmental monitoring nearby such landfills is hampered by high costs of periodic water sampling and chemical composition analyses. It is possible to decrease the number of substances under analysis and thus reduce costs by determining the marker substances, the concentration of which in groundwater near the landfill has stable correlations with the content of other pollutants. The article provides an analysis of the pollutant concentrations in 45 MSW landfills around the world. The results of cluster and correlation analyses made it possible to identify marker substances and establish the target correlation dependences.

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