Evidence of predation pressure on sensitive species by raccoons based on parasitological studies.

To demonstrate predation and potential impacts of raccoons on various species, a total of 108 raccoons from aquatic-associated nature reserves and natural areas in three federal states of Germany, Hesse (n = 36), Saxony-Anhalt (n = 36) and Brandenburg (n = 36), were investigated from a dietary ecological perspective in the present study. Fecal analyses and stomach content examinations were conducted for this purpose. Additionally, as a supplementary method for analyzing the dietary spectrum of raccoons, the parasite fauna was considered, as metazoan parasites, in particular, can serve as indicators for the species and origin of food organisms. While stomach content analyses allow for a detailed recording of trophic relationships solely at the time of sampling, parasitological examinations enable inferences about more distant interaction processes. With their different developmental stages and heteroxenous life cycles involving specific, sometimes obligate, intermediate hosts, they utilize the food web to reach their definitive host. The results of this study clearly demonstrate that spawning areas of amphibians and reptiles were predominantly utilized as food resources by raccoons in the study areas. Thus, common toad (Bufo bufo), common newt (Lissotriton vulgaris), grass frog (Rana temporaria), and grass snake (Natrix natrix) were identified as food organisms for raccoons. The detection of the parasite species Euryhelmis squamula, Isthmiophora melis, and Physocephalus sexalatus with partially high infestation rates also suggests that both amphibians and reptiles belong to the established dietary components of raccoons from an ecological perspective, as amphibians and reptiles are obligate intermediate hosts in the respective parasitic life cycles of the detected parasites. The study clearly demonstrates that raccoons have a significant impact on occurrence-sensitive animal species in certain areas and, as an invasive species, can exert a negative influence on native species and ecosystems.

Diversity, phylogeny and intraspecific variability of Paradiplozoon species (Monogenea: Diplozoidae) parasitizing endemic cyprinoids in the Middle East.

Diplozoidae are common monogenean ectoparasites of cyprinoid fish, with the genus Paradiplozoon being the most diversified. Despite recent studies on Diplozoidae from Europe, Africa and Asia, the diversity, distribution and phylogeny of this parasite group appears to be still underestimated in the Middle East. The objective of this study was to investigate the diversity, endemism and host specificity of diplozoids parasitizing cyprinoid fish from the Middle East, considering this region as an important historical interchange of fish fauna, and to elucidate the phylogenetic position of Middle Eastern Paradiplozoon species within Diplozoidae. Four Paradiplozoon species were collected from 48 out of 94 investigated cyprinoid species. Three known species, Paradiplozoon homoion, Paradiplozoon bliccae and Paradiplozoon bingolensis, were recorded on new cyprinoid host species, and a new species, Paradiplozoon koubkovae n. sp., was recorded on Luciobarbus capito and Capoeta capoeta from the Caspian Sea basin in Iran and Turkey. Paradiplozoon bliccae, exhibiting a wide host range in the Middle East, expressed both morphological and genetic intraspecific variabilities. The four Paradiplozoon species collected in the Middle East were placed in divergent clades, showing the rich evolutionary history of diplozoid parasites in the Middle East. Our study also revealed that two lineages of African diplozoids have a Middle Eastern origin. We stress the importance of applying an integrative approach combining morphological, ecological and molecular methods to reveal the real diversity of diplozoids.

Parasites of Sardinella maderensis (Lowe, 1838) (Actinopterygii: Clupeidae) and Their Potential as Biological Tags for Stock Identification along the Coast of West Africa.

This study is the first to provide information on the parasite fauna of Sardinella maderensis along the coasts of Benin and Ghana, and the first to investigate the potential use of parasites as biological tags in fish population studies in the area. It may thus serve as a starting point for upcoming studies. From February to June 2021, a total of 200 S. maderensis were sampled from the fishing port of Cotonou (Benin) and the Elmina landing site (Ghana). The prevalence and abundance of each parasite were recorded. The following are the outcomes of this study: Parasite species, such as Parahemiurus merus, Mazocraeoides sp. and Hysterothylacium fortalezae, were recorded along the coasts of Benin and Ghana, while Anisakis sp(p). and Tentacularia coryphaenae were only recorded along the coast of Benin. Parahemiurus merus was the most prevalent and abundant among all the parasites recorded. Anisakis sp(p). and T. coryphaenae were selected as having potential in the stock identification of S. maderensis. Both parasites were only recorded along the coast of Benin at a low prevalence. As a result, examinations of more S. maderensis from each location for these parasites may justify their use in stock identification studies.

Raccoons contraband - The metazoan parasite fauna of free-ranging raccoons in central Europe.

The invasive raccoon (Procyon lotor) is an abundant carnivore and considered as an important potential vector of infectious diseases and parasites in Europe. Raccoons show a broad, opportunistic, omnivorous food spectrum. Food supply and habitat quality in urban areas are very attractive for the generalist raccoon. This inevitably leads to increased interaction with humans, domestic animals and livestock, making the raccoon a potentially suitable zoonosis vector. In its autochthonous range, especially in the Eastern and Midwestern United States, the raccoon has been studied very intensively since the beginning of the 20th century. Whereas, basic field biology and parasitology studies in Germany and Europe are lacking and have only been conducted sporadically, regionally and on small sample sizes. In the presented study 234 raccoons from central Germany were comprehensively examined for their metazoan parasite fauna. The present study shows for the first time an extremely diverse parasite fauna in raccoons outside their native range and proves their essential role as intermediate hosts and hosts for ecto- and endoparasites. A total of 23 different parasite species were identified, five of which are human pathogens, 14 of which are new for the parasite fauna of raccoons in Europe. The human pathogenic raccoon roundworm Baylisascaris procyonis is the most common parasite species in this study, with a prevalence of up to 95%. The digenetic trematode Plagiorchis muris, another human pathogenic parasite species, was detected for the first time in raccoons. The ongoing spread of invasive carnivores and the associated spread and transmission of their parasites and other pathogens increases the potential health risk of wild and farmed animals as well as humans. An increase in parasitic diseases in humans (e.g. raccoon roundworm) is to be expected, especially in urban areas, where raccoons are becoming more and more abundant.

Parasite Fauna and Coinfections in Urban Rats Naturally Infected by the Zoonotic Parasite Angiostrongylus cantonensis.

When the zoonotic parasite of rodents that can cause human neuroangiostrongyliasis, i.e., Angiostrongylus cantonensis, is found in its natural definitive hosts, it is usually reported in isolation, as if the rat lungworm were the only component of its parasite community. In this study, we report the coinfections found in rats naturally infected by A. cantonensis in urban populations of Rattus norvegicus and Rattus rattus in Valencia, Spain. In addition to the rat lungworms, which were found in 14 of the 125 rats studied (a prevalence of 11.20%), 18 other parasite species (intestinal and tissular protists, microsporidia and helminths) were found, some of them with high burdens. Fourteen of these nineteen species found are potential zoonotic parasites, namely Blastocystis, Giardia duodenalis, Cryptosporidium spp., Enterocytozoon bieneusi, Encephalitozoon hellem, Toxoplasma gondii, Brachylaima spp., Hydatigera taeniaeformis s.l. larvae, Hymenolepis nana, Hymenolepis diminuta, Angiostrongylus cantonensis, Calodium hepaticum, Gongylonema neoplasticum and Moniliformis moniliformis. The total predominance of coinfected rats as well as their high parasite loads seem to indicate a trend towards parasite tolerance.

Gastrointestinal Microbiota and Parasite-Fauna of Wild Dissostichus eleginoides Smitt, 1898 Captured at the South-Central Coast of Chile.

Dissotichus eleginoides has a discontinuous circumpolar geographic distribution restricted to mountains and platforms, mainly in Subantarctic and Antarctic waters of the southern hemisphere, including the Southeast Pacific, Atlantic and Indian oceans and in areas surrounding the peninsular platforms of subantarctic islands. The aim of this work was to determine and characterize the gastrointestinal parasitic and microbial fauna of specimens of D. eleginoides captured in waters of the south-central zone of Chile. The magnitude of parasitism in D. eleginoides captured in waters of the south-central zone of Chile is variable, and the parasite richness is different from that reported in specimens from subantarctic environments. Next-generation sequencing (NGS) of the microbial community associated to intestine showed a high diversity, where Proteobacteria, Firmicutes, and Bacteriodetes were the dominant phyla. However, both parasitic and microbial structures can vary between fish from different geographic regions.

Gastrointestinal parasitic infestation in the Rock ptarmigan Lagopus muta in the French Alps and French Pyrenees based on long-term sampling (1987-2018).

Data presented in this work represents the first record of parasites from the Alpine and Pyrenean Lagopus muta subspecies, providing valuable information to consider for conservation management. From 1987 to 2018, 207 Rock ptarmigans were collected in the framework of a long-term sanitary monitoring in France. Eight parasites were found in the Alpine Rock ptarmigan, and one in the Pyrenean subspecies. Only two parasites occurred with high prevalence in the Alpine Rock ptarmigan: Capillaria caudinflata (38.9%) and Eimeria sp. (34.7%). Prevalence of the other parasites (Ascaridia compar, Cestodes, Amphimerus sp. and Trichostrongylus tenuis) was lower than 20%. Dispharynx nasuta was found with a prevalence of 52.9% in the Pyrenean Rock ptarmigan. Overall, we found a spatially aggregated distribution of parasites in the northern French Alps, probably due to both favourable climatic conditions for parasite cycle and high host density. Statistical analyses indicated a positive effect of altitude and latitude on C. caudinflata occurrence whereas risk factors for Eimeria sp. were the distance from urban areas and land cover. In addition, the majority of the infested birds came from areas close to ski-pistes, where human disturbance increases the susceptibility to diseases, causing stress to wildlife.

Gastrointestinal parasite infestation in the alpine mountain hare (Lepus timidus varronis): Are abiotic environmental factors such as elevation, temperature and precipitation affecting prevalence of parasite species?

Information concerning factors regulating Alpine mountain hare (Lepus timidus varronis) populations such as host-parasite interactions is missing as only a few parasitological surveys exist of this subspecies. Parasites are not only dependent on their host but also on suitable environmental conditions for infestation. Abiotic environmental factors have an important regulating role on parasites in mammals. It is estimated that the elevation range of parasites is likely to shift in response to alternate host movement and changes in climate. Here we assess the parasitic infestation in the Alpine mountain hare by analysing the parasites in faeces and comparing the parasite infestation at different elevation ranges and at varied weather conditions for two years in the Austrian Alps. Almost half of the faecal samples were free of parasites (46.2%, n = 52). Most frequent was the infection by Coccidia (46.2%), whereas stomach intestine strongylids, Trichuris spp, and Cestoda were only found in 9.6% of all faeces. Hence, only Coccidia may be prevalent enough to regulate Alpine mountain hare populations in the Austrian Alps. Elevation had a significant positive effect on the infection of animals by Trichuris spp, whereas temperature had a significant negative effect on the infection by any parasite traceable in faeces and, when looking at the parasite groups individually, on Coccidia.

Host body size and the diversity of tick assemblages on Neotropical vertebrates.

Identifying the factors that influence the species diversity and distribution of ticks (Acari: Ixodida) across vertebrate host taxa is of fundamental ecological and medical importance. Host body size is considered one of the most important determinants of tick abundance, with larger hosts having higher tick burdens. The species diversity of tick assemblages should also be greater on larger-bodied host species, but empirical studies testing this hypothesis are lacking. Here, we evaluate this relationship using a comparative dataset of feeding associations from Panama between 45 tick species and 171 host species that range in body size by three orders of magnitude. We found that tick species diversity increased with host body size for adult ticks but not for immature ticks. We also found that closely related host species tended to have similar tick species diversity, but correcting for host phylogeny did not alter the relationships between host body size and tick species diversity. The distribution of tick species was highly aggregated, with approximately 20% of the host species harboring 80% of all tick species, following the Pareto principle or 20/80 Rule. Thus, the aggregated pattern commonly observed for tick burdens and disease transmission also holds for patterns of tick species richness. Our finding that the adult ticks in this system preferentially parasitize large-bodied host species suggests that the ongoing anthropogenic loss of large-bodied vertebrates is likely to result in host-tick coextinction events, even when immature stages feed opportunistically. As parasites play critical roles in ecological and evolutionary processes, such losses may profoundly affect ecosystem functioning and services.

Alien species and their zoonotic parasites in native and introduced ranges: The raccoon dog example.

The raccoon dog (Nyctereutes procyonoides) is a canid that is indigenous in East Asia and alien in Europe, where it was introduced more than half a century ago. The aim of this study was to compare the parasite faunas associated with raccoon dogs in their native and introduced ranges, and to identify zoonotic parasite species. We examined 255 carcasses of hunted raccoon dogs from Estonia and recorded a total of 17 helminth species: 4 trematodes, 4 cestodes and 9 nematodes. The most prevalent parasite species were Uncinaria stenocephala (97.6%) and Alaria alata (68.3%). Average parasite species richness was 2.86 (the highest was 9) and only two animals were not parasitized at all. Although the infection intensity was determined by weight and not by sex, all animals infected with more than five helminth species were males. We also found that animals infected with higher numbers of helminth species fed significantly more on natural plants. Intentional consumption of grass may represent a self-medicating behaviour among raccoon dogs. We included the Estonian data into a wider comparison of raccoon dog parasite faunas and found a total of 54 helminth taxa, including 28 of zoonotic potential. In Europe, raccoon dogs are infected with a minimum of 32 helminth species of which 19 are zoonotic; in the native range they are infected with 26 species of which 17 are zoonotic. Most species were nematodes or trematodes, with fewer cestodes described. The recent increase in the number and range of raccoon dogs in Europe and the relatively high number of zoonotic parasite taxa that it harbours suggests that this species should be considered an important source of environmental contamination with zoonotic agents in Europe.

Recovery of Oswaldotrema nacinovici from Whimbrels (Aves) in Korea.

Adult specimens of Oswaldotrema nacinovici (Digenea: Philophthalmidae) have been first identified in Korea from 2 migratory birds (whimbrels, Numenius phaeopus) which were found dead at a western seashore area near Gunsan. The worms were recovered in the intestine of these birds. The worms were morphologically characterized by a large ventral sucker in comparison to the oral sucker, an external seminal vesicle extending beyond the posterior margin of the ventral sucker, and conspicuous uterine seminal receptacle. It was noteworthy that metacercariae-like bodies were contained within the inflated regions of 2 ceca. Other intestinal trematode species found in whimbrels included Spelotrema pygmeum, Gynaecotyla squatarolae, Maritrema obstipum, and Himasthla megacotyle. Zoonotic potential of these trematode species should be taken into considerations.

Recovery of Oswaldotrema nacinovici from Whimbrels (Aves) in Korea

Adult specimens of Oswaldotrema nacinovici (Digenea: Philophthalmidae) have been first identified in Korea from 2 migratory birds (whimbrels, Numenius phaeopus) which were found dead at a western seashore area near Gunsan. The worms were recovered in the intestine of these birds. The worms were morphologically characterized by a large ventral sucker in comparison to the oral sucker, an external seminal vesicle extending beyond the posterior margin of the ventral sucker, and conspicuous uterine seminal receptacle. It was noteworthy that metacercariae-like bodies were contained within the inflated regions of 2 ceca. Other intestinal trematode species found in whimbrels included Spelotrema pygmeum, Gynaecotyla squatarolae, Maritrema obstipum, and Himasthla megacotyle. Zoonotic potential of these trematode species should be taken into considerations.

Macroparasites and their communities of the European eel Anguilla anguilla (Linnaeus) in the Czech Republic.

This paper summarises the results of parasitological examinations of the European eel Anguilla anguilla (Linnaeus) in the Czech Republic, carried out at the Institute of Parasitology, Czech Academy of Sciences (previously the Czechoslovak Academy of Sciences) within the period of 50 years (1958-2008). Even though this survey is limited to the Czech Republic, it provides extensive data probably incomparable with any other study anywhere regarding the number of eels examined and parasites found. A total of 723 eels was examined from 42 localities that belong to all of the three main river drainage systems in the country, i.e. the Elbe, Danube and Oder river basins. Of the 31 species of adult and larval macroparasites including Monogenea (4 species), Trematoda (3), Cestoda (3), Nematoda (11), Acanthocephala (5), Hirudinea (1), Bivalvia (1), Copepoda (1), Branchiura (1) and Acariformes (1), most of them (30) were recorded from the Elbe River basin. These parasites can be divided into three main groups regarding their host specificity: parasites specific for eels (26%), non-specific adult parasites occurring also in other fishes (61%) and non-specific larvae (13%). The highest number (19) of parasite species was recorded in the Mácha Lake fishpond system in northern Bohemia. The parasite communities in eels from the individual localities exhibited large differences in their species composition and diversity depending on local ecological conditions. The parasite fauna of A. anguilla in the Czech Republic is compared with that in other European countries. The nematode Cucullanus egyptae Abdel-Ghaffar, Bashtar, Abdel-Gaber, Morsy, Mehlhorn, Al Quraishy et Mohammed, 2014 is designated as a species inquirenda.