Parasite Species Composition Research Articles

Паразиты обыкновенной щиповки Cobitis taenia Linnaeus, 1758 (Pisces: Cobitidae) в Саратовском водохранилище

Objective of research. To study the species composition of the parasite fauna and the infestation rate of the spiny loach Cobitis taenia Linnaeus, 1758 from Saratov Reservoir. Materials and methods. The material was collected in the Mordovo-Kol’tsovsky area of the Reservoir (the middle part of the reservoir) in 2009 and 2014–2015. Fishing was carried out by a hydrobiological net. Totally 47 individuals of spiny loach were investigated by the method of full parasitological autopsy. Collection, fixation and office studies were carried out using the standard technique; diagnostics of species composition of parasites — by identification guides. To estimate the rate of fish invasion, we used the common parasitological indices: extensity of invasion, intensity of invasion and the index of abundance of parasites. Results and discussion. 7 species of parasites belonging to 5 classes: Monogenea — 1, Cestoda — 1, Trematoda — 3, Nematoda — 1, Bivalvia — 1 were found in the spiny loach Cobitis taenia Linnaeus from Saratov Reservoir. The species composition of parasites and the level of host infestation directly depend on the lifestyle and nutrition of fishes. Eating the infected benthic and weed bed invertebrates (oligochaetes, larvae and adult insects), the spiny loach becomes infected with 3 species of helminths. 4 species of parasites infect the host using the active infestation way. Most of the parasites found in fish from different families and groups are wide specific. The parasite fauna includes 1 species, narrow specific for the spiny loach (monogenea Gyrodactylus latus Bychowsky, 1933) and 1 species specific for loaches (fam. Cobitidae) — metacercariae of Holostephanus cobitis Opravilova, 1968. For 4 species of parasites, the spiny loach is the final (definitive) host, for 3 — intermediate. The dominant species in the composition of the parasite fauna C. taenia is the trematode H. cobitidis (mtc.); the extensity of infection with it reaches 97,9%, the abundance index is 10,8 ind. Fluke larvae infect fishes (using the active way) penetrating through the skin. The most pathogenic for spiny loach parasites are the monogenea G. latus, metacercariae of trematodes H. cobitidis and Paracoenogonimus ovatus Katsurada, 1914, the larva of the nematode Raphidascaris acus Bloch, 1779.

Transmission of parasites in the coastal waters of the Arctic seas and possible effect of climate change

The review deals with the biodiversity, life cycles, distribution and temperature adaptations of parasites circulating in the coastal waters of northern polar seas. Special attention is given to helminths of marine birds, which are the most common parasites in the coastal waters. Among them, the focus is on trematodes. Factors responsible for the impoverished species composition of parasites in the Arctic are analyzed. It is shown that species without free-living larvae in the life cycle have an advantage in this environment. The abundance of cestodes and acanthocephalans in Arctic seabirds is linked with the high proportion of crustaceans in their diet. The phenomenon of nonspecific parasitism (occurrence of parasites in atypical host species) is analyzed from an evolutionary viewpoint. Characteristic features in the spatial distribution of infection of marine coastal invertebrates with parasite larvae are considered, and factors that determine it are specified. The prevalence of infection in intermediate hosts is closely connected with the abundance of final hosts, which makes it possible to estimate the abundance of final hosts in a given region and reveal trends in its changes. Trematodes have a high potential for temperature acclimation. This facilitates their transmission in the northern seas but, on the other hand, makes it unlikely that the transmission process would be intensified upon an increase in summer temperatures resulting from climate warming. However, intensification of transmission may well occur due to the prolongation of the warm season (“transmission window”), which has been predicted and is already observed. It is suggested that warming in the Arctic promotes both the entry of certain “southern” species into the Arctic and the trans-Arctic interpenetration of the North Atlantic and North Pacific parasitic faunas. A case is made for the necessity to broaden the scope of parasitological research in the Arctic and Subarctic, including parasitological monitoring at the reference sites of the sea coast.

Prevalence and risk factors of gastrointestinal parasitic infections in goats in low-input low-output farming systems in Zimbabwe

A longitudinal study was conducted in low-input low-output farming systems to determine the prevalence of gastrointestinal parasitic infections in different age groups, sex and associated risk factors in goats. A total of 580 indigenous goats were randomly selected in areas representing the five agro-ecological regions of Zimbabwe in the dry and wet seasons. Blood and faecal samples were collected from each animal and egg/oocyst per gram of faeces (epg/opg), larval culture, and packed cell volumes (PCV) were determined. Factors affecting parasitic infections were evaluated. Highest prevalence was determined for Eimeria oocysts (43%), strongyles (31%) and lower levels in trematodes and cestodes. Parasites identified were Haemonchus, Strongyloides and Oesophagostomum. Area, season, sex and age significantly influenced patterns of gastrointestinal infections (P<0.05). Cannonical correlations indicated that parasite species composition varied by area and impacts of risk factors also differed. Risk of infection was very high for goats sampled in Natural regions (NR) I, II, III (OR=6.6–8.2; P<0.05) as compared to those in NR IV and V. Highest helminths and Eimeria infections were observed in the wet vs. dry season (P<0.05). Young animals were more susceptible to parasitic infections (P<0.05). Prevalence was higher in males than females, with odds of infection for males being almost three times to that for females (P<0.0001). Knowledge concerning gastrointestinal helminth biology and epidemiological infection patterns caused by these parasites is essential in the development of appropriate control strategies and this has a potential to reduce production losses.

Variation in parasite communities in Oreochromis niloticus linked with precipitation

The aquatic environment can be studied either directly by a regular monitoring of water quality parameters or indirectly by using bioindicators, such as fish parasites. The most common groups of parasites examined to date in response to environmental stress are ectoparasites including trichodinids and monogeneans. To assess the effects of drought on the prevalence of ectoparasites and the number of species of parasites in fish, we collected fish specimens in the summer and early autumn (January to April) in the years 2014 and 2015. The first collection took place after a year with regular precipitation; however the second collects occurred after reduction of about 70% in rain rates. We collect 85 samples of fish. The parasites were surveyed by the fresh smears of gills and feces, or by histopathological examination with Hematoxylin-Eosin and Giemsa stain. Before the drought (in the first collection in 2014), the prevalence of parasites in fish collected was 28.5% (18/63,), but after the drought in 2015, the prevalence was 73.5% (64/87). We counted at random, the number Trichodina sp. of the histopathology of the gills of fish and we observed that the parasites average before the drought was 08.04 ± 2.05e after the drought was 3.33 ± 1:35, with no statistically significant difference between the observation periods. Before the drought, Trichodina sp. (18/23) Myxobolus sp. (3/23), Henneguya sp. (9/23) and Ichthyophthirius multifiliis (2/23) were found. After dry the found parasites were: Trichodina sp. (27/27, 100%), Henneguya sp. (4/27, 14.8%) and Monogenea (2/27, 7.4%). We conclude that the reduction in precipitation and the water crisis generated by it significantly increased the prevalence of ectoparasites in gills, which reinforces the parasites indication of fish as a biological indicator of changes in environmental quality. The study suggested that the species composition of fish parasites is influenced by environmental parameters.

The diversity of parasites in the Chinese sleeper Perccottus glenii Dybowski, 1877 (Actinopterygii: Perciformes) under the conditions of large-scale range expansion

It has been found that the species composition of parasites infesting the Chinese sleeper Perccottus glenii in water bodies from the nonnative part of its range is more depleted. Here, the phylogenetic distances between parasites exceed those in the native part of the range. It has been revealed that parasitological differences between P. glenii populations from the nonnative and native parts of the range, as well as between populations inside the nonnative part, have similar composition and abundance of the host-specific and euryxenous components in the parasitic fauna. It has been shown that these differences are determined by the genesis of sites from which P. glenii is introduced, as well as the local conditions of the recipient water bodies.

Сообщества паразитов гольяна &lt;i&gt;Phoxinus phoxinus&lt;/i&gt; (L.) из водоемов Приполярного Урала

Видовой состав паразитов рыб, в том числе гольяна, из горных и предгорных озер и водотоков Приполярного и Полярного Урала в его европейской части, за исключением некоторых сведений о паразитах рыб из рек Щугор и Кожим, не известен. Между тем, эти данные важны для решения вопросов о происхождении и формировании гидрофауны указанной территории. Это особенно интересно в связи с результатами многолетних ихтиофаунистических исследований разнотипных озер и водотоков западных склонов Приполярного и Полярного Урала. Для сравнения видового состава паразитов гольяна из разных водоемов использованы коэффициент Чекановского и критерий Фишера. Паразитофауна гольяна из обследованных водоемов отличается случайным и обедненным видовым составом, слабой зараженностью большинством паразитов рыбы. Сходство видового состава паразитов изученных водоемов не превышает 50 %. Сообщества паразитов гольяна из р. Кожим и оз. № 2 соответствуют характеристикам незрелого сообщества. Черты остальных сообществ не подходят ни под одно из ранее описанных сообществ паразитов гольяна. Наибольшее число особей паразитов собрано при вскрытии гольяна из оз. № 2, самое высокое значение их биомассы отмечено в оз. № 3. Самые низкое число особей паразитов отмечено у гольяна из р. Балбанью и оз. М. Балбанты, наименьшая их биомасса зарегистрирована у рыбы из оз. Большое, несколько выше она в р. Кожим и Балбанью, далее по этому показателю идут оз. М. Балбанты, оз. Падежаты и оз. № 2.

Variation in Parasite Communities in Spottail Shiners (Notropis hudsonius) Linked with Precipitation.

The Richelieu River, Quebec, is a highly-regulated waterway subject to numerous anthropogenic influences from municipal effluents and agricultural activities. Parasite communities in 234 spottail shiners (Notropis hudsonius) were examined from 4 localities in late spring 2003 and 2004. Component species richness varied between 15 and 18 species in 2003 but declined to 9 to 13 in 2004, while total parasite abundance was consistently lower in 2003. Parasite component community similarity among localities could not be directly linked to available upstream water quality measurements or anthropogenic activity and was best explained by precipitation. Total precipitation in May 2003 was approximately 40% more than in May 2004, presumably altering patterns of runoff, river flow rates, and water quality. This study suggests that fish parasite species composition and richness in the Richelieu River are influenced by environmental parameters which in turn ultimately are driven by a combination of climatic conditions and anthropogenic activities in the watershed.

Climate-driven tipping-points could lead to sudden, high-intensity parasite outbreaks.

Parasitic nematodes represent one of the most pervasive and significant challenges to grazing livestock, and their intensity and distribution are strongly influenced by climate. Parasite levels and species composition have already shifted under climate change, with nematode parasite intensity frequently low in newly colonized areas, but sudden large-scale outbreaks are becoming increasingly common. These outbreaks compromise both food security and animal welfare, yet there is a paucity of predictions on how climate change will influence livestock parasites. This study aims to assess how climate change can affect parasite risk. Using a process-based approach, we determine how changes in temperature-sensitive elements of outbreaks influence parasite dynamics, to explore the potential for climate change to influence livestock helminth infections. We show that changes in temperate-sensitive parameters can result in nonlinear responses in outbreak dynamics, leading to distinct ‘tipping-points’ in nematode parasite burdens. Through applying two mechanistic models, of varying complexity, our approach demonstrates that these nonlinear responses are robust to the inclusion of a number of realistic processes that are present in livestock systems. Our study demonstrates that small changes in climatic conditions around critical thresholds may result in dramatic changes in parasite burdens.

Nematode parasites infecting the starry batfish Halieutaea stellata (Vahl) (Lophiiformes: Ogcocephalidae) from the East and South China Sea.

The starry batfish Halieutaea stellata (Vahl) is a small, benthic fish found in Indo-West Pacific Oceans. However, our present knowledge of the helminth parasites of this fish is still fragmentary. In this study, a total of 29 fish collected from the East and South China Sea were examined to determine the prevalence, intensity and species composition of helminth parasites in H. stellata. Using morphological and molecular approaches, four species of nematodes were found parasitic in this fish host, including the adults and fourth-stage larvae of Raphidascaroides nipponensis Yamaguti 1941; adults and third-stage larvae of Raphidascaris lophii (Wu 1949), third- and fourth-stage larvae of Hysterothylacium larval type IV-A of Shamsi, Gasser & Beveridge 2013 and third-stage larvae of Hysterothylacium amoyense (Hsü 1993). Halieutaea stellata represents a new host record for the three last-named nematodes. Raphidascaroides nipponensis with the highest prevalence (82.5%) and intensity (mean = 13.5) of infection was considered as the dominant parasite species in H. stellata. The detailed morphology of the different developmental stages of the four nematode species was studied using light and scanning electron microscopy. All nematode species were also genetically characterized by sequencing and analysing the internal transcribed spacer (ITS) of the ribosomal DNA. This study provides further data on the occurrence of nematode parasites in H. stellata and also contributes to facilitate an accurate and rapid diagnosis of the infection by these little-known nematodes.

Correlation between amphibian habitat utilisation and blood parasite infection levels the Pongola floodplain

Correlation between amphibian habitat utilisation and blood parasite infection levels the Pongola floodplain Frogs play an important role in the food web where they serve as both predators and prey. They thus play a key role in the stability of most ecosystem communities. Studies have shown that there is high correlation between the relative abundance of prey in the area, and the frequency these species are found in the gut contents of frogs in that same area. Southern Africa has a rich frog diversity. Frogs are highly adaptive organisms and have established in almost every suitable habitat on the subcontinent. Even though frogs are found in a wide variety of environments, most species are very specific to the particular habitat in which they are able to survive in and more importantly reproduce in. The aim of this study is to assess and document amphibian species diversity and habitat viability in the Pongola floodplain situated below the Pongolapoort Dam in northern KwaZulu-Natal. To investigate the effect of habitat utilisation on parasite diversity and infection levels a blood parasite survey on the amphibians in this area will also be conducted. In the life cycle of these blood parasites the vector is often either a mosquito or a leech. The leech is more likely to infect the more aquatic species while the mosquito will infect the terrestrial species. The hypothesis of this study is that the parasite species composition will reveal information that will enable us to better understand habitat requirements and utilisation.

Determinants of prevalence and intensity of infection with malaria parasites in the Blue Tit

AbstractParasite species are usually specialists utilising specific host species, but parasite assemblages may differ substantially even between populations of the same species and show seasonal and annual fluctuations. Host characteristics such as individual age and sex may also affect parasite species composition and abundance. Here, we report the occurrence of malaria parasites in the Blue Tit (Cyanistes caeruleus) inhabiting Gotland (Sweden) across 5 years. Using PCR-based techniques, we found eight cytochrome b lineages belonging to genus Plasmodium (pTURUD1, pBT7, pSGS1, pSW2, pGRW11) and Haemoproteus (hPARUS1, hPHSIB1, hWW2) with the overall prevalence of 65 %. The Plasmodium infections predominated (prevalence of 49.5 %), whereas Haemoproteus infection rate was much lower (prevalence of 16.5 %). We showed significant differences in infection status between study years and age classes when all parasite lineages were analysed together or the two most common lineages were analysed separately. Overall, older birds showed higher prevalence. A significant interaction between year and genus effect significantly explained variation in infection intensity. This interaction stems from a significant yearly variation of the infection intensity with Plasmodium, while such an effect is not present for Haemoproteus infections. More importantly, the intensity of infection with Haemoproteus was significantly higher than with Plasmodium in 3 out of the 4 study years with data.

Histopathology and helminth parasites of African catfish Clarias gariepinus (Burchell, 1822) in relation to heavy metal pollution in a subtropical river system

Summary In a study aimed to determine the histopathology, component parasite communities and level of selected heavy metals, African catfish Clarias gariepinus from three rivers in Zimbabwe (Gwebi, Manyame and Mukuvisi) were analysed for heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) in the gills, liver, kidney and muscles. The histopathology of these tissues was assessed by microscopic examination of stained thin sections. Metazoan parasite diversity and species composition in fish along different sites of the rivers were determined and compared. Levels of Cd, Fe, Pb and Zn were lowest in the Gwebi, Cr and Cu in the Manyame, and Ni in the Mukuvisi River. There were significant differences (P < 0.5) in concentration of iron and nickel in the gill and liver tissues of fish among the three rivers while significant differences in concentration of iron and lead were observed in muscle tissue. Gill chronic inflammation and ossification were significantly different (P < 0.5) in fish from among the three rivers. Chronic inflammation, hemosiderin deposits and bile accumulation in the liver were also significantly different (P < 0.5) among the three rivers and so was the extent of chronic inflammation in the kidney tissue. Lamellar fusion was slightly more present in gills of catfish from the Mukuvisi than the Gwebi River. The parasite community of C. gariepinus comprised three monogenean, two cestode and three nematode species. The least polluted Gwebi River had the highest parasite community diversity while the most polluted Mukuvisi River had the lowest diversity. Fish parasite community structure is thus a potential indicator of river pollution, while heavy metal pollution is a potential threat to fish and human health in the system.

Comparison of PfHRP-2/pLDH ELISA, qPCR and Microscopy for the Detection of Plasmodium Events and Prediction of Sick Visits during a Malaria Vaccine Study

BackgroundCompared to expert malaria microscopy, malaria biomarkers such as Plasmodium falciparum histidine rich protein-2 (PfHRP-2), and PCR provide superior analytical sensitivity and specificity for quantifying malaria parasites infections. This study reports on parasite prevalence, sick visits parasite density and species composition by different diagnostic methods during a phase-I malaria vaccine trial.MethodsBlood samples for microscopy, PfHRP-2 and Plasmodium lactate dehydrogenase (pLDH) ELISAs and real time quantitative PCR (qPCR) were collected during scheduled (n = 298) or sick visits (n = 38) from 30 adults participating in a 112-day vaccine trial. The four methods were used to assess parasite prevalence, as well as parasite density over a 42-day period for patients with clinical episodes.ResultsDuring scheduled visits, qPCR (39.9%, N = 119) and PfHRP-2 ELISA (36.9%, N = 110) detected higher parasite prevalence than pLDH ELISA (16.8%, N = 50) and all methods were more sensitive than microscopy (13.4%, N = 40). All microscopically detected infections contained P. falciparum, as mono-infections (95%) or with P. malariae (5%). By qPCR, 102/119 infections were speciated. P. falciparum predominated either as monoinfections (71.6%), with P. malariae (8.8%), P. ovale (4.9%) or both (3.9%). P. malariae (6.9%) and P. ovale (1.0%) also occurred as co-infections (2.9%). As expected, higher prevalences were detected during sick visits, with prevalences of 65.8% (qPCR), 60.5% (PfHRP-2 ELISA), 21.1% (pLDH ELISA) and 31.6% (microscopy). PfHRP-2 showed biomass build-up that climaxed (1813±3410 ng/mL SD) at clinical episodes.Conclusion PfHRP-2 ELISA and qPCR may be needed for accurately quantifying the malaria parasite burden. In addition, qPCR improves parasite speciation, whilst PfHRP-2 ELISA is a potential predictor for clinical disease caused by P. falciparum.Trial RegistrationClinicalTrials.gov NCT00666380

New Records of Lake Baikal Leech Fauna: Species Diversity and Spatial Distribution in Chivyrkuy Gulf

The study of several Lake Baikal leech collections offered us the possibility to determine species diversity in the Chivyrkuy Gulf, the biggest one in the lake. As a result, the first information on the Chivyrkuy Hirudinea fauna (Annelida, Clitellata) has been revealed. There are two orders and four families of leeches in the Chivyrkuy Gulf: order Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and order Arhynchobdellida (families Erpobdellidae and Haemopidae). In total, 22 leech species and 2 subspecies belonging to 11 genera were identified. Of these, 4 taxa belong to the family Glossiphoniidae (G. concolor, A. hyalina, A. heteroclita f. papillosa, and A. heteroclita f. striata) recorded in Baikal for the first time. Representatives of 8 unidentified species (Glossophinia sp., Baicaloclepsis sp., Baicalobdella sp., Piscicola sp. 1, Piscicola sp. 2, Erpobdella sp. 1, Erpobdella sp. 2, and Erpobdella sp. 3) have been also recorded. The checklist gives a contemporary overview of the species composition of leech parasites, their hosts, and distribution within the Chivyrkuy Gulf. The analysis of spatial distribution has shown that the leech species diversity is correlated with the biological productivity of the bay. The most diverse community of leech species is detected in the eutrophic zone of the lake.

An environmental assessment of the parasite fauna of the reef-associated grouperEpinephelus areolatusfrom Indonesian waters

Sixty Epinephelus areolatus were examined for metazoan fish parasites in Indonesia, off Segara Anakan lagoon, Java and in Balinese waters. The study revealed 21 different parasite species, and 14 new host and locality records. The anisakid nematodes Anisakis typica and, for the first time in Indonesia, Anisakis sp. HC-2005 were identified by using molecular methods. Ecological parameters were calculated for both sites off the anthropogenically influenced Segara Anakan lagoon and the relatively undisturbed reference site at the southern Balinese coast. The fish from Segara Anakan demonstrated a significantly higher enzymatic activity (Hepatosomatic index) and a significantly reduced number of heteroxenous gut helminths (e.g. the digenean Didymodiclinus sp., the nematode Raphidascaris sp. and the acanthocephalan Serrasentis sagittifer). Other regional differences for E. areolatus included ecto-/endoparasite ratio, endoparasite diversity, the parasite species composition and prevalence of infection of the respective parasite species. We applied the stargraph method to visualize observed regional differences using grouper parasites as biological indicators for the sampled coastal ecosystems at both sampling sites.

The parasite fauna of the Patagonian toothfish Dissostichus eleginoides off the Falkland Islands

The parasite fauna of juvenile Dissostichus eleginoides, while they inhabit the Falkland's shelf, was examined, giving new detailed information on spatial, ontogenic and seasonal variations. A total of 24,943 parasites from 15 different taxa were found in the stomach of 502 individual fish. Parasite species composition and abundance allowed separation of toothfish by area between the north-west and south-east of the Falklands. The digenean, Elytrophalloides oatesi, and the nematodes, Hysterothylacium spp. and Anisakis spp., were the most common, all with a prevalence >20%. For some seasons ontogenic changes in abundance were significant in these three parasite taxa, and this is discussed in terms of ontogenic and seasonal changes in diet. Elytrophalloides oatesi and Hysterothylacium spp. showed spatial and seasonal differences in abundance with greater numbers in the warmer waters of the north-west and during the summer months. Differences in abundance of E. oatesi between the Falklands and other regions indicate its potential for use as a biological tag to study toothfish movements and population structure; however, more seasonal data would be required before this technique could be used.

Blood parasites, body condition, and wing length in two subspecies of yellow wagtail (Motacilla flava) during migration

Blood parasites of migrating yellow wagtails of two subspecies--Motacilla flava feldegg and Motacilla flava flava-were studied on a sample of 473 birds caught in spring and autumn periods in Bulgaria. We controlled eight "migration waves" (flocks captured in different evenings) of yellow wagtails for four parameters--average body mass, average fat level, average wing length, and average prevalence of different hematozoan species. Gametocytes or meronts of a total of six species of hematozoa belonging to three genera were identified-Haemoproteus motacillae, Haemoproteus anthi, Plasmodium relictum, Plasmodium subpraecox, Plasmodium cathemerium, and Tryponosoma avium. Mixed infections were detected in 31 cases, of which 14 were of H. anthi/H. motacillae type. Parasite species composition was similar in the two studied subspecies of M. flava. We did not find any significant differences in the overall infection prevalence or number of infecting parasites between M. f. flava and M. f. feldegg. Parasite prevalence and the number of co-infecting parasites in spring were much higher than in fall. Season had a strong influence on the prevalence of H. anthi and H. motacillae, and for both, there was a marginally significant interaction between subspecies and season, but not a season-independent influence of subspecies. Males of M. f. feldegg had a significantly higher overall blood parasite prevalence and prevalence of H. anthi than females. Sex-related differences in the prevalence of other parasites were not significant. Migration waves of yellow wagtails differed in overall infection status and in H. motacillae prevalence, but not for H. anthi prevalence. We also found significant differences in fat score, weight, and wing length between the studied migration waves of the yellow wagtails. Fat scores of birds infected with different hematozoa were lower compared with those of the non-infected birds. This only marginally was true for body weight and was not the case for wing length. Overall, infected birds were in worse condition (estimated as the residual weight after regression with wing length) compared with the non-infected birds, but after controlling for seasonal effects, the differences in condition appeared to be due to migration season and did not significantly differ between infected and non-infected birds caught in the same season.

Parasitological survey of the edible cockle Cerastoderma edule (Bivalvia) on the south coast of Ireland

The edible cockle Cerastoderma edule is one of the most common soft sediment bivalves in Europe and of commercial relevance in some areas of its range. Information on the parasite fauna of cockles is available from several North Sea and Atlantic shore locations. However, little is known from the British Isles in this context. This study provides an inventory of the macroparasites of C. edule sampled from fourteen localities along the south coast of Ireland. Altogether, we identified ten taxa of macroparasites belonging to three major groups. The majority of them were digenean trematodes using cockles as second intermediate host. Infection rates and levels were comparatively low, with the exception of the gymnophallid Meiogymnophallus minutus, which was found to be prevalent at all sampling sites and often very abundant. Whilst parasite species composition in Irish cockles was similar to the one found in conspecifics from northern Europe, it showed distinct differences from the macroparasite fauna reported from C. edule collected in southern Europe and northern Africa.

Deconstructing spatial patterns in species composition of ectoparasite communities: the relative contribution of host composition, environmental variables and geography

ABSTRACTAim We determined whether dissimilarity in species composition between parasite communities depends on geographic distance, environmental dissimilarity or host faunal dissimilarity, for different subsets of parasite species with different levels of host specificity.Location Communities of fleas parasitic on small mammals from 28 different regions of the Palaearctic.Method Dissimilarities in both parasite and host species composition were computed between each pair of regions using the Bray–Curtis index. Geographic distances between regions were also calculated, as were measures of environmental dissimilarity consisting of the pairwise Euclidean distances between regions derived from elevation, vegetation and climatic variables. The 136 flea species included in the dataset were divided into highly host‐specific species (using 1–2 host species per region, on average), moderately host‐specific species (2.2–4 hosts per region) and generalist species (&gt;4 hosts per region). The relative influence of geographic distance, host faunal dissimilarity and environmental dissimilarity on dissimilarity of flea species composition among all regions was analysed for the entire set of flea species as well as for the three above subsets using multiple regressions on distance matrices.Results When including all flea species, dissimilarity in flea species composition was affected by all three independent variables, although the pure effect of dissimilarity in host species composition was the strongest. Results were different when the subsets of fleas differing in host specificity were treated separately. In particular, dissimilarity in species composition of highly host‐specific fleas increased solely with environmental dissimilarity, whereas dissimilarity for both moderately specific and non‐specific fleas increased with both geographic distance and dissimilarity in host species composition.Main conclusions Host specificity seems to dictate which of the three factors considered is most likely to affect the dissimilarity between flea communities. Counter‐intuitively, environmental dissimilarity played a key role in determining dissimilarity in species composition of highly host‐specific fleas, possibly because, although their presence in a region relies on the occurrence of particular host species, their abundance is itself mostly determined by climatic conditions. Our results show that deconstructing communities into subsets of species with different traits can make it easier to uncover the mechanisms shaping geographic patterns of diversity.

Phenotypic plasticity in the greater mouse-eared bat in extremely different roost conditions

Bats use various roost types with a wide spectrum of ecological features. The greater mouse-eared bat Myotis myotis (Borkhausen, 1797), creates nurseries in attics and caves in Central Europe. The stable low temperature and high humidity cave microclimate contrasts that of attics, which may alter species adaptations and life strategies. We analysed population characteristics (composition, body condition, parasite load, and immune response) and genetic relatedness of two proximal M. myotis populations. Age, sexual and parasite species composition were similar between the cave and attic sites. However, a significantly higher parasite load and body condition was detected in the post-partum females and juveniles of the cave colony (n = 263 bats from the cave, 231 from the attic), with the cave colony females having a significantly stronger immune response (n = 2 caves and 2 attics, 20 females per site). There was no evidence for genetic divergence between cave and attic populations (n = 3 caves and 3 attics, 24 females per site), indicating that different population characteristics are not genetically based and that M. myotis is an example of a species with rather unique phenotypic plasticity.