Parasite Fauna Research Articles

Immature trematodes of Lecithochirium sp. (Digenea: Hemiuridae) in the California two-spot octopus (Octopus bimaculatus) from Mexico.

Immature trematodes of Lecithochirium sp. are recorded for the first time as parasites of the California two-spot octopus Octopus bimaculatus from Bahía de los Ángeles, Baja California, Mexico. Thirty-nine O. bimaculatus were examined for trematodes and a total of 100 immature specimens of Lecithochirium sp. were recorded from the crop of seven infected octopuses. Based on these records, O. bimaculatus may act as a second intermediate or paratenic host for these parasites. Partial sequences of the 28S (region D1-D3) ribosomal gene corroborate the identifications based on morphological characters. DNA sequences of the 28S gene from GenBank were analyzed to include the immature samples of Lecithochirium sp. within a hemiurid phylogenetic framework. All immature specimens of Lecithochirium sp. were recovered as monophyletic and Pulmovermis cyanovitellosus was identified as the sister species of Lecithochirium sp. However, due to the lack of molecular data for species of the genus Lecithochirium, these phylogenetic inferences must be taken with caution. Therefore, the morphological and molecular data obtained here provide a foundation for future work to develop a systematic comparison among- and within-species of the genus Lecithochirium. Additionally, the present records of Lecithochirium in O. bimaculus add to the knowledge of the parasite fauna of cephalopods.

From the Balkan towards Western Europe: Range expansion of the golden jackal (Canis aureus)-A climatic niche modeling approach.

In recent decades, a rapid range expansion of the golden jackal (Canis aureus) towards Northern and Western Europe has been observed. The golden jackal is a medium‐sized canid, with a broad and flexible diet. Almost 200 different parasite species have been reported worldwide from C. aureus, including many parasites that are shared with dogs and cats and parasite species of public health concern. As parasites may follow the range shifts of their host, the range expansion of the golden jackal could be accompanied by changes in the parasite fauna in the new ecosystems. In the new distribution area, the golden jackal could affect ecosystem equilibrium, e.g., through changed competition situations or predation pressure. In a niche modeling approach, we project the future climatic habitat suitability of the golden jackal in Europe in the context of whether climatic changes promote range expansion. We use an ensemble forecast based on six presence‐absence algorithms to estimate the climatic suitability of C. aureus for different time periods up to the year 2100 considering different IPCC scenarios on future development. As predictor variables, we used six bioclimatic variables provided by worldclim. Our results clearly indicate that areas with climatic conditions analogous to those of the current core distribution area of the golden jackal in Europe will strongly expand towards the north and the west in future decades. Thus, the observed range expansion may be favored by climate change. The occurrence of stable populations can be expected in Central Europe. With regard to biodiversity and public health concerns, the population and range dynamics of the golden jackal should be surveyed. Correlative niche models provide a useful and frequently applied tool for this purpose. The results can help to make monitoring more efficient by identifying areas with suitable habitat and thus a higher probability of occurrence.

Bacteria and Parasite Fauna of Cultured and Wild Clarias gariepinus in Benue State, Nigeria

Variation in bacteria and parasite load of Clarias gariepinus from pond and wild environments was determined. Of the 30 samples of C. gariepinus, while 6 healthy from the pond environment were examined with 7 different bacteria isolates, 7 diseased C. gariepinus were examined with 7 bacteria isolates. Also, while 3 healthy samples of C. gariepinus from the wild environment were examined with 6 different bacteria isolates, 14 diseased samples were examined with 10 bacteria isolates. Staphylococcus aureus (73.33%) and Escherichia coli (67.67%) were the most prevalent followed by Aeromonas hydrophyla (40.00%) and Streptococcus spp. (36.67%) among the 10 bacteria isolates recovered from the samples of C. gariepinus. Out of the 30 samples of C. gariepinusfrom the pond environment, 6(20.00%) were infested with 3 species of parasites; Eustrongylides spp. (50.00%), Camallanus spp. (83.33%) and Camallanus riparius (33.33%). Out of the 30 samples of C. gariepinus from the wild environment, 11(36.67%) were infested with 4 species of parasites; Eustrongylides spp. (54.55%), Camallanus spp. (72.73%), Caenorhabditis brigsae (36.36) and Chironomus riparius (6.67%). Generally, samples of C. gariepinus from the pond environment were more parasitized than those from the wild environment. Relative to other body parts, the intestine was most associated with bacteria isolates compared to the gills and skin. During the study period, 3 isolates of parasites (Eustrongylides spp., Camallanus spp. and Caenorhabditis brigsae) were recovered and observed to be most prevalent in the intestine of samples of C. gariepinus from the pond environment, 3 parasite species were also recovered from the parasitized samples of C. gariepinus from the wild. Of the body parts of C. gariepinus from the pond and wild environments, the intestine had the highest percentage of parasite infestation of 86.67% from the pond and 83.33% from the wild while the least 13.33% from the pond and 16.67% from the wild environments were recorded for the gills.

Gill monogeneans of neotropical cichlid fish: diversity, phylogenetic relationships, and host-parasite cophylogenetic associations

Host-parasite coevolution is one of the main topics of the evolutionary biology of host-parasite associations. The majority of monogeneans parasitizing fish exhibit a high degree of host specificity. As a result, their evolutionary history might be intertwined with that of their fish hosts. The Cichlidae represent a diverse group of secondary freshwater fish with disjunctive distribution. Host-specific dactylogyrid monogeneans commonly parasitize cichlid fish. Their high diversity is associated with the main areas of cichlid distribution, i.e., Neotropical America and Africa. Nevertheless, the parasite fauna of cichlids from Neotropical America is still underexplored. A total of 31 cichlid species were examined for the presence of monogeneans, with 20 of them being parasitized. On these cichlids, 30 monogeneans belonging to the genera Gussevia, Trinidactylus, and Scadicleithrum were identified, 17 of them potentially representing new species for science. Phylogenetic analyses revealed three monophyletic groups of Neotropic cichlid monogeneans. Genus Gussevia was monophyletic, while Sciadicleithrum resulted polyphyletic. Sciedicleithrum from South America and Sciadicleithrum from Mexico represented two divergent lineages. The plesiomorphic Neotropical cichlid host group for dactylogyrid monogeneans was Cichlini, from which the representatives of other Neotropical cichlid tribes were colonised. Cophylogenetic analyses revealed a statistically significant cophylogenetic signal in the investigated host-parasite system, with host switch and duplication representing the main coevolutionary events for monogeneans parasitizing Neotropical cichlids. This scenario is in accordance with previous studies focussed on dactylogyridean monogeneans parasitizing freshwater fish in Europe and Africa.

Trematodes of Genera Gyrabascus and Parabascus from Bats in European Russia: Morphology and Molecular Phylogeny.

Simple SummaryThe ecology of bats determines their unique parasitic fauna. Most species of worms from bats are highly specialized parasites. We studied parasitic worms of bats that died of natural causes, using classical morphological and molecular phylogenetic approaches. Original drawings, descriptions, and results of molecular phylogenetic analysis for five species of trematodes were provided. We established a broad morphological variability in the studied trematode species, which means that the identification of closely related species may be problematic for researchers. We proposed a taxonomic key for the reliable identification of the studied trematode species. The results of our study contribute to the knowledge of bat helminths and host-parasite relationships in general.Morphological variability of trematodes from bats (Chiroptera) is poorly studied. Since the variability of adult digenean specimens may be rather high, morphological features are often insufficient for the identification of closely related species, and confirmation with the use of molecular data is required. The aim of our study was to combine the morphological and molecular phylogenetic analyses of several bat trematodes from the genera Gyrabascus and Parabascus (Pleurogenidae): Gyrabascus amphoraeformis, Gyrabascus oppositus, Parabascus lepidotus, Parabascus duboisi, and Parabascus semisquamosus, of which G. amphoraeformis and G. oppositus are little known in European Russia. We made detailed morphological descriptions of these trematodes from several definitive hosts, analyzed morphometric features, and generated new partial sequences of the 28S rRNA gene. A broad variability of trematodes of the genera Gyrabascus and Parabascus was revealed both from various host species and from specimens of the same host species. We propose a new taxonomic key for the identification of the studied species. Certain host specificity of these trematodes was revealed.

SPECIES COMPOSITION OF WOLF (CANIS LUPUS) HELMINTH FAUNA IN KAZAKHSTAN

The article presents data on the study of the species composition of wolf helminth fauna in the period from 2019 to 2021. A total of 39 wolves (Canis lupus) were examined, and their parasite fauna was assessed. The study identified the following types of helminths Echinococcus granulosus, Taenia krabbei, Dypilidium spp., Mesocestoides spp., Toxascaris leonina, Trichinella nativa, Dirofilaria repens. The extensiveness of the invasion wolves by helminths was relatively high in the western part region (96.5%), and towards the north-central part region, this indicator significantly decreased (65.2%). The average number of helminths was high, with some infected animals carrying several types of parasites. Thus, the intensity of invasion by helminths in wolves was 7.6 specimens per infected individual host. The research aimed to study the endoparasitic fauna of wild wolves using complex classical parasitological and molecular genetic methods. Samples of helminths were differentiated by amplification and sequencing using the marker gene cytochrome oxidase COX1 (GenBank accession number: MT877205, MZ505444, MZ669895, MZ724175). There is a need to assess the distribution of helminths in intermediate and final hosts populations and provide appropriate health education to avoid maintaining parasite life cycles and infestations, which will become a public health problem in the future.

Composition and structure of the parasitic fauna of Hypostomus spp. (Loricariidae: Hypostominae) from a Neotropical river in Brazil.

Hypostomus are abundant in Brazilian rivers and streams. In the Ivaí River, the loricariids represent 20.3% of the total species of the basin. Of these 13 species belong to Hypostomus. However, to date, there are no studies on these fish parasitic fauna. Thus, this research aimed to analyze the distribution of the parasitic infracommunity of six species of Hypostomus from the Ivaí River and investigate how the infracommunity is structured in these hosts. One hundred and twenty-eight fish were analyzed, belonging to six sympatric species of Hypostomus (Hypostomus hermanni, H. cochliodon, H. albopunctatus, H. regani, Hypostomus sp.1, and Hypostomus sp.2); of these, 92.9% were parasitized with at least one taxon, totaling 1478 specimens of parasites. The parasitic fauna was composed of the ectoparasites Trinigyrus anthus, T. carvalhoi, Unilatus unilatus (monogeneans), and Placobdella spp. (hirudinea), and the endoparasites Austrodiplostomum compactum (digenean) and Procamallanus annipetterae (nematode). The parasites exhibited similar patterns of infection in all hosts, including a low number of species, low diversity, and numerical dominance of a group of parasites. However, permutational multivariate analysis of variance (PERMANOVA) showed different parasite species compositions among the hosts. Hypostomus cochliodon and H. regani had the highest parasite richness, while Hypostomus sp.1 and Hypostomus sp.2 showed low abundance and intensity of parasitic infections. However, Hypostomus sp.1 showed the highest values of evenness, although the parasite composition in both species did not differ. The results presented herein contribute to increasing the knowledge about the parasitic fauna of Hypostomus spp. from the Ivaí River by presenting new hosts and locality records.

Pharmaceutical contamination and biotic factors affecting parasitism in common carp ( Cyprinus carpio )

Increasing levels of persistent pollutants in the aquatic environment are likely to have serious impacts on host–parasite relationships. In this study, common carp (Cyprinus carpio) of the same age, origin and source were randomly stocked in two pond localities, one fed by treated water from a municipal sewage treatment plant and the other fed by a non-polluted stream. Fish biometric parameters and health status were evaluated after 2 years of exposure through the determination of somatic condition indices, parasite load and concentration of pharmaceuticals. Municipal pollutants were found at both sites, although at significantly higher levels at the polluted site, with antidepressants, antibiotics, analgesics and beta-blockers dominant in each case. Owing to a higher availability of natural food, carp from the polluted locality displayed significantly better body condition than those from the control site, while parasite abundance and species richness were higher at the control site. Our results suggest that, compared with fish from control locality exhibiting diverse and abundant natural parasite fauna, fish from the polluted locality were better able to cope with parasites, due to their better condition status. Fish from this study site may have profited from municipal waste water by avoidance of high levels of parasite infections.

Parasitic Helminth fauna of Clarias gariepinus and Parachanna Obscura from a reputable Fish Farm, Jos, Plateau State, Nigeria

Parasitic Helminth fauna of Clarias gariepinus and Parachanna Obscura from a reputable Fish Farm, Jos, Plateau State, Nigeria

Systematic literature review of Hyphessobrycon eques: A support for the improvement of captive breeding

Hyphessobrycon eques has a great prominence in fishkeeping and scientific research. In this context, a systematic literature review was performed to assist in the improvement of captive breeding of this species and to identify knowledge gaps. Notably, of the 966 articles published between 1997 and 2020 found in an initial screening of the digital libraries of Google Scholar, PubMed, SciELO, Science Direct, and Scopus, only 56 represented research on the species according to the established criteria. Considering aspects pertinent to captive reproduction, 25 studies were selected. These studies addressed information regarding reproduction; embryonic, larval, and juvenile development of the species; parasitic fauna; limiting concentrations of prophylactic agents; food preferences; and dietary supplements already used for these fish. Only seven studies reported information on the physicochemical characteristics of water in natural habitats, with great variations in several parameters, mainly those related to temperature. In 5 of the 25 selected studies, information related to reproductive characteristics and/or embryonic, larval, and juvenile development was addressed. However, only two studies developed experimental studies with information relevant to the captive breeding of the species. Studies to identify parasitic fauna and to analyze the use of prophylactic agents were also found. As for the information gaps on the cultivation of the species, there are no studies related to nutrition seeking to determine the species nutritional needs, including feeding frequencies, feeding durations, and specific amounts of food. Therefore, this review offers a great support for the breeding of H. eques by highlighting opportunities for new scientific studies that could enrich and collaborate in the breeding of this ornamental fish.

Parasite Community Analysis of The Gray Snapper Lutjanus Griseus (Perciformes,Lutjanidae) in a Tropical Region of The Southern Gulf of Mexico.

SummaryThe gray snapper Lutjanus griseus is a commercially important fish species along its distribution range in the western Atlantic Ocean. However, despite its importance, there is still little knowledge about its parasitic fauna for the Mexican coasts of the Gulf of Mexico. The aims of this research were to generate a list of the parasitic fauna present in juvenile gray snapper L. griseus from a coastal lagoon located in southeastern Mexico, to evaluate the infection levels of parasites and to determine the relationship between the abundance of parasites and the fish size and condition factor. Samples of L. griseus (12 – 29.2 mm) were obtained in two periods of the year (dry and rainy seasons) to examine the intra-annual variability of its parasitic fauna. A total of 17 parasite species were recorded belonging to six taxonomic groups (Myxozoa, Monogenea, Digenea, Cestoda, Nematoda and Acanthocephala). The highest levels of infection (abundance, prevalence and intensity of infection) were found for the monogeneans Euryhaliotrema griseus and Euryhaliotrema fastigatum. There were no significant correlations between the total abundance of parasites and the fish condition and size (total length) in not any of the two seasons studied, suggesting that the body size and the biological condition index of the host did not directly influence the abundance of parasites in early life stages of L. griseus. Moreover, the species of parasites found that could be zoonotic for humans through the consumption of raw or inadequately cooked fish were the nematodes Contracaecum sp. type 1, Contracaecum sp. type 2, Cucullanus pargi and Pseudoterranova sp. The presence of the monogeneans E. griseus and E. fastigatum was also highlighted because these ectoparasite species are known to cause harm to fish under culture systems. All the parasite species found in this study, except nematodes, were new records of geographic distribution.

Parasitofauna of farm red deer (Cervus elaphus) in Western Polissya of Ukraine

The formation of the parasite fauna of wild ungulates and control of diseases caused by them is an essential veterinary measure in the breeding of deer. The study aimed to conduct monitoring studies on the infestation of red deer parasites (Cervus elaphus) during commercial cultivation during acclimatization in the Western Polissya of Ukraine. Faecal samples (n = 30) were taken from females of four ecotypes of the Eastern European breed, English, Hungarian, F1 crossbreed (Eastern European x Western European breed), and males of different ecotypes. The research was performed between May and September 2020 at the Department of Parasitology and Ichthyopathology, Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv. Eggs and larvae from nine species of helminths were found in the faeces of parasitic deer at Amila Farm: Trichostrongylus axei, Ostertagia ostertagia, Cooperia oncophora, Haemonchus contortus, Chabertia ovina, Murisillo capides (Capillaria bovis), Dicrocoelium dendriticum, including eight species of nematodes and one species of trematodes, as well as oocysts of two species of protozoa: Eimeria ellipsoidalis, Eimeria brasiliensis. Intensity of Trichostrongylus nematode, Ostertagia, Coperia, Hemonhus, Habertia, Aonhoteca (capillary), strongyloides and mulleria larvae on the scale of invasiveness (up to 100 EGF/LGF) in May and September was low, and dicrocelia trematodes eggs – low and medium (1–10, 11–100 EGF) in September, indicating the subclinical course of helminthiasis and their constant release during this period into the environment. The intensity of parasitic protozoan infestation was also low (1–10 OGF) in May and relatively high (11–100 OGF) in September. The intensity of parasitic protozoan infestation was also low (1–10 OGF) in May and relatively high (11–100 OGF) in September.

Molecular-genetic approaches to species identif ication of platyhelminthes of the genus Ligophorus (Monogenea) parasitising f lathead mullet.

Mugil cephalus L., 1758 (flathead mullet) is a valuable commercial fish and a promising object of artificial breeding in the Black Sea and the Sea of Azov, and the study of its parasite fauna is important for fishery and mariculture. Monogeneans of the genus Ligophorus are common ectoparasites dwelling on the gills of mullets. Two representatives of this genus parasitise flathead mullet in the Azov-Black Sea region, namely Ligophorus mediterraneus Sarabeev, Balbuena et Euzet, 2005 and Ligophorus cephali Rubtsova, Balbuena, Sarabeev, Blasco- Costa et Euzet, 2006. Morphological identification of these species requires spending much time and a high level of experience in monogenean taxonomy. For quick and correct species identification of these parasites, we have developed a genotyping approach based on the polymerase chain reaction of allele-specific gene sites for various Monogenea species. A fragment of the 28S ribosomal gene, which includes conserved and variable sites, was chosen as a genetic marker. Three approaches were used as follows: amplified fragment length analysis, allelespecific PCR with endpoint detection and allele-specific real-time PCR using SYBR Green intercalating dye. The first approach was by obtaining PCR products of different lengths that were specific either to L. mediterraneus or to L. cephali. This approach was implemented due to the presence of several variable sites located at a distance from each other. The PCR mixture contained three primers: one forward and two reverse. The forward primer was complementary to the conserved site, which did not differ between species. Reverse primers were speciesspecific and, for each species, they were complementary to different DNA regions located 100 bp apart. As a result, L. mediterraneus was characterized by shorter amplicons than L. cephali. For the second and third approaches, a pair of primers was designed according to the following principle: the forward primer was complementary to both species, since it was selected for the conserved gene region. Reverse primers were species-specific and were designed for the 28S variable region. The two parasite species were distinguished by three-point mutations. Thus, one pair of primers was complementary to L. mediterraneus, the other, to L. cephali. The amplified fragment length analysis and the allele-specific real-time PCR demonstrated 100 % coincidence of genotyping results compared with Sanger sequencing. The developed genotyping protocols can be used not only to distinguish two species of Ligophorus from flathead mullet in ecological studies and veterinary practice but also for further development of similar approaches for other monogeneans, among which there are many pathogenic species.

Natural history collections: collaborative opportunities and important sources of information about helminth biodiversity in New Zealand

ABSTRACT Only a small fraction of the Earth’s total biodiversity has been described. This is particularly true of parasitic fauna, due to the paucity of taxonomic expertise, funding, and interest in parasites. It is expected that co-extinctions will become the main cause of species loss with potentially half of the parasite species becoming extinct prior to their discovery. This article addresses this issue and highlights case studies from the Otago Museum (OMNZ) (Dunedin, New Zealand), providing examples of successful collaborations between government organisations, museums, and parasitologists in bridging knowledge gaps in parasite diversity. The case studies presented focus on the parasitic helminths from opportunistic necropsies of stranded marine mammals and deceased birds. Collections from these case studies have doubled the size of the parasite collection at the OM, making this institution the most important repository of parasitic helminths in the country. We encourage such collaborations between museums, governing bodies, indigenous communities, ecologists and parasitologists in enhancing our knowledge of parasite diversity. Furthermore, we urge scientists to deposit both host and parasite tissues from surveys, vouchers, along with their respective metadata so that samples can be adequately stored and curated, thus ensuring that parasite collections become a legacy for future generations of scientists.

Syngamus trachea in free-ranging white stork (Ciconia ciconia) nestlings in Switzerland.

Syngamosis is a disease caused by the strongylid nematode Syngamus trachea, which infects the respiratory tract of various bird species around the world. The parasite appears to be harmful for a wide variety of avian orders, occasionally leading to a fatal outcome, particularly in young birds.The aim of this study was to examine the parasitic fauna in deceased or euthanized, free-ranging white storks nesting at the Zoo Basel in 2019 and 2020; and to assess the extent to which these parasites contributed to the wild birds' death.In five out of 24 necropsied white storks, an infection with S. trachea was diagnosed based on morphological analysis of adult nematode stages and eggs, in combination with PCR amplification and sequencing of DNA extracted from female worms. The main pathological changes affected the white storks’ respiratory tract and a mixed cell tracheitis was diagnosed in the histopathological examination of three of the five infected birds. Some birds displayed additional lesions compatible with syngamosis, namely partially degenerated parasitic structures with concurrent granulomatous inflammation in the lung and multifocal acute hemorrhages in the bronchi and parabronchi. Coprological examinations (fecal flotation technique, fecal sedimentation technique, sodium acetate acetic acid formalin procedure and Ziehl-Neelsen staining) from the intestinal content as well as a PCR for Toxoplasma gondii on brain, lung, heart, liver, and spleen tissue yielded negative results in all examined individuals. In the absence of further major pathological findings, S. trachea was assumed to have significantly contributed to the death of the infected birds.

The hitchhiker's guide to Australian conservation: A parasitological perspective on fauna translocations

AbstractTranslocation is a widely used conservation tool for reintroducing, introducing or restocking wildlife for conservation purposes. Disease and parasites are often unintended hitchhikers during translocations. Conservation managers have begun considering the health, disease risk and parasite loads of their species post‐translocation, but not often during the translocation itself. When parasites and diseases are considered during the translocation, they are often dealt with via medical interventions resulting in the complete eradication of parasites leaving the host vulnerable to new or novel disease or parasite loads, or disrupting specialised host–parasite interactions or disease dynamics. To determine the extent of consideration and intervention of parasites and diseases in the Australian context, we conducted an aggregate scoping review of wildlife conservation translocations resulting in 98 identified translocations of 61 species with most (75%) being translocations of 40 species of mammals. Of the 98 translocations identified, only 40 (41%) described any management actions to monitor the health or disease of the translocation, such as health checks, post‐mortems or sampling of disease or parasite fauna. Surprisingly, some literature mentioned specific diseases or parasites impacting a population (29% of 90 translocations), but only 16 (16%) undertook intervention to prevent these further spreading. When considering general trends over time, more translocations are considering parasites and disease in their planning, and some management action is usually taken; however, medical intervention remains low. In order to ensure that parasites and diseases are part of conservation thinking, we provide a flowchart for managers that can be implemented into future translocations that consider both the negative consequences of disease and parasites, and the ecological necessity and potential benefits of retaining co‐evolved parasites and diseases.

INTESTINAL PARASITES OF DOGS FROM SE-YAKHA (YAMAL) IN CONTEMPORARY

Archaeological work is actively carried out on the territory of Yamal, while traces of invasion are also found in coprolites and the cultural layer, and therefore, it is of interest to compare modern and ancient parasite fauna. Combined and sedimentation methods were used to analyze 11 stool samples of domestic dogs collected in 2021 during the expedition in the Se-Yakha settlement. Prevalence was established – 54.55%, while the dominant parasite was Sarcocystis (27.27%), T. leonina was detected less often – 18.18% and tapeworm – 9.09%, trematode invasion was not recorded, although opisthorchiasis is constantly recorded in the region. Morphometric studies of the eggs of the tapeworm and sporocysts were carried out. The tapeworm eggs are 61.50±1.3 µm long; egg width 41.7±1.03 µm; the width of the mouth is 22.20±0.88, which most closely matches the description of D. nihonkaiense (syn. D. klebanovskii). The eggs of the tapeworms are a frequent archaeological find, but the species is not established. According to morphological and ecological characteristics, protozoa (length 14.40±0.30 µm; width 10.25±0.18 µm; shape index 1.40±0.04) correspond to the description of S. grueneri. Most likely, dogs in ancient times also had them, but due to their small size and thin shell, they were not preserved.

HELMINTH FAUNA IN SHEEP IN THE VALLEY OF THE TEBERDA RIVER

In connection with the movement of small cattle from one region of the Russian Federation to another with close contact of agricultural ruminants with wild ruminants and carnivores, as well as with the impact of anthropogenic factors, etc. in a certain territory, the parasite fauna of ruminants changes, and pastures in the valley of the Teberda River are no exception. Invasive diseases are a limiting factor in obtaining high-quality mutton. The studies were performed on sheep breeding farms of Muhu, LLC and the private sector located in the Karachay-Cherkess Republic, Karachayevsky District, and Verkhnyaya Teberda Village. In total, 91 samples of faeces were taken from the Karachai sheep of various age and sex groups. Conventional methods were used to diagnose helminthiasis. Helminth fauna in the sheep was represented by one suborder, five genera and three species of nematodes, namely, Strongylata, Protostrongylus, Nematodirus, Bunostomum, Nematodirella, Trichocephalus, Muellerius capillaris, Dictyocaulus filaria and Strongyloides papillosus; one cestode species Moniezia benedeni, and one trematode species Dicrocoelium lanceatum, and protozoa of the genus Eimeria were also identified. Mixed invasions were most often diagnosed in the animals in 52.7%, of which the most common was the suborder Strongylata + genus Eimeria (Infection Prevalence = 8.8%).

PARASITE FAUNA OF WOOD BISON (BISON BISON ATHABASCAE RHOADS, 1897) LIVING IN THE UST’-BUОTОMА NURSERY, LENA PILLARS NATURE PARK, REPUBLIC OF SAKHA (YAKUTIA)

The results of the study are presented on the parasite fauna of the wood bison from the Ust’-Buоtоmа Nursery, the Lena Pillars Nature Park (Yakutia), that participates in the re-acclimatization program with subsequent release into the wild in their new habitats. The breeding stock was brought from the Canadian Elk Island National Park (Alberta). During the study, six endoparasite species were found, including 1 species of the protozoa, Eimeria bovis, 2 species of cestodes, Moniezia expansa and Moniezia benedeni, and 3 species of nematodes, Cooperia spp., Ostertagia spp. and Trichostrongylus spp. In the course of parasitological studies, zooanthroponosis of bison was excluded and endoparasites were detected that were common to wild and domestic large ungulates typical both for Yakutia and Canada according to epizootological data. In this regard, a potential exchange of helminths and protozoa was possible between natural biocenoses and agro-biocenoses. The parasites found in the Nature Park are a factor of natural selection, but they must be taken into account in the event of a characteristic clinical picture, and in case of loss of livestock, especially young animals, to implement effective therapeutic and preventive measures.

FORMATION MONITORING OF PARASITE FAUNA IN STABLED ANIMALS OR ANIMALS IN ENCLOSED GRAZING AREAS

Monitoring studies were performed on biological diversity of parasite fauna in domesticated animals at the territory of the Joint Russian-Armenian Scientific Experimental Centre, within the piedmont zone of Armenia with moderate continental climate at 900-1200 m above the sea level. The study species were large and small ruminants, rabbits and hens. All the animals except sheep were kept indoors (stalls). We found 3 trematode species, 4 cestode species and 5 nematode species based on seasonal coproovoscopic and larvoscopic examinations, as well as an incomplete helminthological dissections of 5 sheep. The infection of sheep and cattle with hematophagous parasites was also detected and the infection of hens and rabbits with helminths and protozoa was found. Oribatid mites Scheloribates sp. were isolated from the studied soil samples. We also found and studied land and freshwater molluscs, intermediate hosts of a number of important parasite species for the infection. The land molluscs were found to have naturally-acquired invasions with larval forms of Protostrongylidae and Dicrocoeliidae. In total, we found 20 helminth species, 5 ixodid ticks, 1 oribatid mite and 7 protozoa, and vectors: 2 species of freshwater molluscs and 1 species of land molluscs.