Helminth parasitism in the coyote, Canis latrans, from the Rolling Plains of Texas

Eighteen helminth species were recovered from 150 coyotes necropsied in West Texas: 2 trematodes, Alaria marcianae (12% of hosts infected) and Alaria sp. (0.6%); 3 cestodes, Taenia pisiformis (39%), T. serialis (4%) and Mesocestoides corti (58%); 2 acanthocephalans, Oncicola canis (26%) and Pachysentis canicola (23%); and 11 nematodes, Physaloptera rara (60%), Pterygondermatites cahirensis (37%), Spirocerca lupi (83%), Subulura s.p. (1.3%), Filaroides osleri (28%), Ancylostoma caninum (87%), Toxascaris leonina (89%), Dermatoxys veligera (1.3%), Syphacia sp. (0.6%), Dirofilaria immitis (0.6%), and Trichuris sp. (0.6%). All hosts were infected with from 1 to 10 helminth species (-x = 5.5 species). Simpson's index was very low (0.12) indicating a diverse helminth fauna. The helminth fauna of West Texas coyotes demonstrated only low similarity with those from other geographic regions in North America. Significant positive relationships were found between pairs of prevalent helminth species in terms of frequency of occurrence. Comparison of mean levels of infection between pairs of helminth species indicated 6 significant relationships. A clumped distribution was indicated in those helminths utilizing arthropod intermediate hosts or paratenic hosts. Analysis of prevalence of helminth species in terms of host sex by frequency of occurrence and mean levels of infection revealed only one significant relationship; T. leonina occurred more frequently in females than males. Similar analysis of age relationships ( ? 1 year and ? 2 years) and helminth parasitism indicated P. rara occurred more frequently in older animals while A. caninum and P. cahirensis occurred more frequently and with higher levels of infection in younger animals. The results of these findings are discussed in terms of food niche and behavioral aspects of this host from the Rolling Plains of Texas.     

A host-parasite list of the protozoan and helminth parasites of New Guinea animals

Ewers W. H. 1973. A host-parasite list of the protozoan and helminth parasites of New Guinea animals. International Journal for Parasitology, 3: 89–110. This paper provides a hostparasite list for protozoan and helminth parasites recorded from native animals of New Guinea. The synonomy of both hosts and parasites are given together with references to the literature of each species of parasite.     

Helminth communities of loggerhead turtles (Caretta caretta) from Central and Western Mediterranean Sea: The importance of host's ontogeny

We investigated the factors providing structure to the helminth communities of 182 loggerhead sea turtles, Caretta caretta, collected in 6 localities from Central and Western Mediterranean. Fifteen helminth taxa (10 digeneans, 4 nematodes and 1 acanthocephalan) were identified, of which 12 were specialist to marine turtles; very low numbers of immature individuals of 3 species typical from fish or cetaceans were also found. These observations confirm the hypothesis that phylogenetic factors restrict community composition to helminth species specific to marine turtles. There were significant community dissimilarities between turtles from different localities, the overall pattern being compatible with the hypothesis that parasite communities reflect the ontogenetic shift that juvenile loggerheads undergo from oceanic to neritic habitats. The smallest turtles at the putative oceanic, pelagic-feeding stage harboured only the 2 digenean species that were regionally the most frequent, i.e. Enodiotrema megachondrus and Calycodes anthos; the largest turtles at the putative neritic, bottom-feeding stage harboured 11 helminth taxa, including 3 nematode species that were rare or absent in turtles that fed partially on pelagic prey. Mean species richness per host was low (range: 1.60–1.89) and did not differ between localities. Variance ratio tests indicated independent colonization of each helminth species. Both features are expected in ectothermic and vagrant hosts living in the marine environment.     

Temporal variation in helminth infracommunities of the Gafftopsail pompano,Trachinotus rhodopus (Pisces: Carangidae) off the Pacific coast of Mexico

Temporal variation of the helminth infracommunity structure in the Gafftopsail pompano Trachinotus rhodopus was studied during bi-monthly revisions of samples collected offshore from Puerto Ángel, Oaxaca (Mexican Pacific) in 2018. In total, 110 specimens of T. rhodopus were subjected to a parasitic review. Helminths found were identified to the lowest possible taxonomic level (six species and three genera) by means of morphological and molecular data. Attributes of the helminth infracommunities are described through statistical analyses, showing stability in terms of their richness throughout the year. However, variations were found in helminth abundance related to the seasonality of samplings, which may be associated with the life cycles of the parasites, the host species' gregarious behavior, the availability of intermediate hosts, and/or the diet of T. rhodopus.     

New data on gastrointestinal helminths in shags (Phalacrocorax verrucosus) at Kerguelen Archipelago

To date, the knowledge of the helminth communities of Antarctic birds is scarce or fragmented. Knowledge about diseases and parasites is crucial for understanding and managing ecosystems, particularly in isolated areas where host species are more sensitive to new diseases or parasite infections. It has been showed that variations in rate of parasitism may occur between populations of host species. Two major non-exclusive hypotheses have been proposed to explain such variability: exposure to parasitism and, perhaps more important, life history strategies of hosts. We studied the helminth community of the Kerguelen Shag Phalacrocorax verrucosus, an endemic seabird species of the Kerguelen Archipelago. We provide new data on the helminths infecting this species from partial or complete digestive tracts of two birds. Two nematodes (Contracaecum rudolphii s.l. and Ingliseria cirrohamata) were found free or attached to the wall of the proventriculus of birds, while the acanthocephalan Corynosoma sp. and the cestode species Tetrabothrius sp. occurred in the intestine of the shags. The genus Tetrabothrius is reported for the first time in Kerguelen Shags and in this area. The analysis of stomach contents from 41 live Kerguelen Shag individuals revealed infection by Contracaecum nematodes. The proportion of infected birds differed between colonies, possibly in relation to differential exposure to infected fish hosts.     

Functional and phylogenetic uniqueness of helminth and flea assemblages of two South African rodents

The loss of a particular species from a community may have different effects on its functioning, depending on the presence or absence of functionally similar or phylogenetically close species in that community (redundancy). Redundancy is thus defined as the fraction of species diversity not expressed by functional or phylogenetic diversity. We assessed functional and phylogenetic alpha- and beta-redundancy in helminth and flea assemblages of two species of South African rodents, Rhabdomys dilectus and Rhabdomys pumilio, using community uniqueness as the inverse indicator of redundancy. We asked whether patterns of functional and phylogenetic alpha- and beta-uniqueness differed between (i) parasite groups (endo- versus ectoparasites), (ii) host species within parasite groups, and (iii) biomes within host species. We found differences between the two hosts in the functional and phylogenetic alpha-uniqueness (but not beta-uniqueness) of flea, but not helminth, assemblages. Significant correlations between the alpha-uniqueness of parasite assemblages and the total parasite prevalence were found only for phylogenetic uniqueness and only in helminths. Pairwise site-by-site dissimilarities in uniqueness (beta-uniqueness) and pairwise dissimilarity in prevalence were significantly associated (positively) in helminths but not in fleas. A between-biome difference in functional (but not phylogenetic) alpha-uniqueness was found in both helminth and flea assemblages harboured by R. pumilio. We conclude that the resilience of parasite assemblages in terms of the effect on hosts depends not only on their transmission strategy but also on traits of host species and environmental factors.     

Helminth communities in small mammals in southeastern New South Wales

• 1.1. Changes in the composition and abundance of 5 marsupial and 3 eutherian mammal species, and of their helminth communities pre- and post-perturbation by wildfire at Nadgee and Timbillica State Forests in southeastern coastal New South Wales during the period September 1977 to September 1985 are reported.
• 2.2.Dasyurid marsupials (Antechinus stuartii, Antechinus swainsonii and Sminthopsis leucopus), peramelid marsupials (Perameles nasuta and Isoodon obesulus) and native eutherian rodents (Rattus fuscipes and Rattus lutreolus) occurred pre-fire. These species and the introduced house mouse (Mus musculus) occurred post-fire.
• 3.3. All host taxa harboured a diverse helminth fauna dominated by nematodes. The helminth communities in A. stuartii, A. swainsonii, S. leucopus and R. lutreolus represented more than 70%, those in P. nasuta, R. fuscipes and M. musculus represented more than 50% and that in I. obesulus represented less than 40% of the total helminth faunas known to occur in these hosts throughout their geographic ranges in Australia.
• 4.4. Adult nematodes of Capillaria sp. 11 and Tetrabothriostrongylus mackerrasae occurred in all host groups, those of Peramelistrongylus skedastos occurred in both marsupial groups but not in rodents, larval stages of the ascaridoid nematode Ophidascaris robertsi occurred in all host groups and physalopterid nematode larvae believed to be Abbreviata spp. occurred in dasyurid marsupials and in rodents but not in peramelid marsupials.
• 5.5. Four helminth communities were recognised: one in the dasyurid marsupials, a second in the peramelid marsupials, a third in the native rodents and a fourth in the introduced house mouse.
• 6.6. Differences in the helminth communities in host taxa pre- and post-wildfire were associated with the ecological strategies of the hosts and their roles as opportunistic invaders (M. musculus), fire-enhanced species (S. leucopus) or slow recolonisers (P. nasuta) post-perturbation by wildfire.

     

A checklist of helminth parasites of Elasmobranchii in Mexico

A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided.     

Helminth Diversity in Synanthropic Rodents from an Urban Ecosystem

Richness and diversity of parasites depend on a set of interrelated factors related to the characteristics of the host, the environment and the parasites itself. In the City of Buenos Aires, rodent communities vary according to landscape structure. The goal of this paper was to study the variations of helminth richness and diversity among invasive rodent species in different landscape units of the City of Buenos Aires. 73% of the rodents were parasitized with at least one of the 10 identified helminth species. Each rodent species presented its own characteristics in terms of richness, diversity and helminth composition, keeping these characteristics still occupying more than one landscape unit. The infracommunities with greater diversity corresponded to R. norvegicus due to its high values of parasitic richness, proportion of infected hosts and parasite prevalence. Instead, R. rattus and M. musculus infracommunities had lower diversity since a high percentage of them presented a unique helminth species. Within the city, the inhabitants of shantytowns would be the most exposed to zoonotic diseases transmitted by rodents due to high abundance of rodents harboring a high parasite load, including species like Hymenolepis nana and H. diminuta, recognized worldwide from a zoonotic aspect.     

Helminth communities of herons (Aves: Ardeidae) in southern Italy

The helminth communities of nine species of herons from southern Italy were studied and compared. Of 24 taxa found including seven digeneans, seven nematodes, six cestodes and four acanthocephalans, only five taxa were found in more than one heron species, and five of the 21 taxa that could be identified to species level were classified as ‘heron specialists’. The total number of helminth species per heron species ranged from 1 in Botaurus stellaris to 9 in Ixobrychus minutus with infection levels generally low. A statistical comparison was carried out for herons with a sample size > 5. At the infracommunity level, only I. minutus clearly differed from other heron species. Diversity parameters of heminth infracommunities did not significantly differ among heron species. Species richness ranged from just 0.3 to 2.3 helminth taxa per individual host, and the Brillouin index, from 0 to 0.3. Total helminth abundance did not exceed 40 worms per host except in a single case of Ardeola ralloides. Infracommunities clearly were dominated by single helminth species. The present study confirms a depauperate helminth community in herons from southern Italy. Comparison with data from Spain and the Czech Republic showed strong quantitative similarities with values obtained in the present study. Results also suggest that the composition of local helminth communities are strongly variable depending on geographical location as is demonstrated by comparison with data from other European areas. However, whether herons in Europe naturally host depauperate helminth communities or these communities are depauperate because of other factors is unknown.     

A survey of the helminths of Rattus sordidus,the canefield rat,together with a description of Ancistronema coronatum n. g., n. sp. (Nematoda: Chabertiidae)

The digestive systems of 86 canefield rats from Ingham, Queensland were examined for parasites. One species of cestode and seven species of nematode were found, all but one being new host records. The helminth community was characterised in terms of core, secondary and satellite species. No core species were identified, but Nippostrongylus typicus and Odilia emanuelae were identified as secondary species. All other species were identified as satellite species. The strongyloid nematode Ancistronema coronatum n. g., n. sp. is described. Ancistronema differs from other genera in the Chabertiidae in having a short buccal capsule and in the number and shape of the elements of the internal and external leaf crowns. This is the first record of a strongyle from Australian rodents. It is postulated that it came into Australia with ancestral Rattus sp. hosts which colonised Australia from Indonesia less than a million years ago.     

Morphological and molecular identification of helminths of the greater bulldog bat Noctilio leporinus (Quiroptera: Noctilionidae) from Campeche,Mexico

Surveys on parasites of bats from the Americas have been conducted, but information on helminths is still scarce, especially in the Neotropical region. In Mexico, there are species of bats that lack of a record for helminth species, such as members of the family Noctilionidae. The present study describes for the first time the helminths of Noctilio leporinus in Campeche, Mexico. In 2017, six specimens of N. leporinus were studied for helminths. The species identification of helminths was based on morphological studies and molecular analysis of fragments of the 28S rDNA. All bat specimens were infected for at least one helminth species. Three helminth taxa were identified: the trematode Pygidiopsis macrostomum, and the nematodes Tricholeiperia cf. proencai, and Heligmonellidae gen. sp. The morphological identification of P. macrostomum was confirmed by sequence analysis of 28S rDNA gene. The phylogeny of P. macrostomum grouped our sequence with other sequences of the same species collected in Brazil. The phylogenetic tree of Heligmonellidae gen. sp. indicated that the helminth belongs to clade formed by the species Odilia bainae, Nippostrongylus magnus and Nippostrongylus brasiliensis of the family Heligmonellidae. The phylogenetic analysis of the 28S sequences of T. cf. proencai did not show any similarity or close affinity with nematodes from which that gene has been sequenced to date. The findings of the present study increase the number of helminth species parasitizing bats in Mexico.     

Gastrointestinal helminths of King penguins (Aptenodytes patagonicus) at Crozet Archipelago

Communities of helminths are known to be related to feeding behaviors of hosts. While climate change and overfishing can impact food availability for Antarctic piscivorous predators, knowledge about infectious and parasitic diseases among Antarctic species is scarce or fragmentary. We studied the helminth community of King penguins (Aptenodytes patagonicus) from the Crozet Archipelago, the main breeding area of the species. Based on a sample of 41 individuals found freshly dead from predation or starvation, the gastrointestinal helminth community in King penguins was composed of 1 species of cestode (Tetrabothrius wrighti) and 2 species of nematodes (Tetrameres wetzeli and Contracaecum heardi). Cestodes formed the core of the helminth community (97.5% of worms collected) with a prevalence of infestation of 100% and a mean intensity of 178.6 worms per host. Sources of infestation and pathologies caused by these worms are also discussed.     

The helminth infracommunities in three species of herons (Aves: Ardeidae) from Ukraine

This survey analysed the helminth communities associated with three Ukrainian heron species (Ardea cinerea, Ardea purpurea, Nycticorax nycticorax) collected throughout 1947–2019. The sample analysed included 128 specimens, and 55 helminth species were identified. Of these, the most diverse taxonomic group was trematodes with 29 species, followed by cestodes with 14 species, nematodes with nine, and acanthocephalans with three species. The helminth infracommunities were found to be similar across all three host species. Furthermore, the distance to the coastal regions impacts both diversity and species richness in infracommunities.     

The decay of similarity with geographical distance in parasite communities of vertebrate hosts

Aim The rate at which similarity in species composition decays with increasing distance was investigated among communities of parasitic helminths in different populations of the same host species. Rates of distance decay in similarity of parasite communities were compared between populations of fish and mammal hosts, which differ with respect to their vagility and potential to disperse parasite species over large distances. Location Data on helminth communities were compiled for several populations of three mammalian host species (Ondatra zibethicus, Procyon lotor and Canis latrans) and three fish host species (Perca flavescens, Catostomus commersoni and Esox lucius) from continental North America. Methods Distances between localities and similarity in the composition of helminth communities, the latter computed using the Jaccard index, were calculated for all possible pairs of host populations within each host species. Similarity values were then regressed against distance to see if they decayed at exponential rates, as reported for plant communities; the significance of the regressions was assessed using randomization tests. Results The number of hosts examined per population did not correlate with the number of helminth species found per population, and thus sampling effort is unlikely to have confounded the results. In four (two mammals and two fish) of the six host species, similarity in helminth communities decayed exponentially with distance. When the log of similarity is plotted against untransformed distance, the slopes obtained for the two fish species are lower than those obtained for the two mammalian host species. Main conclusions Similarity in the composition of parasite communities appears to decay exponentially with increasing distance in some host species, but not in all host species. The rate of decay is not necessarily associated with the vagility of the host. Although distance decay of similarity is generally occurring, it seems that other ecological processes, related either to the host or its habitat, can obscure it.     

Über Vogelparasiten auf der Insel Mellum an der niedersächsischen Nordseeküste

Parasitological investigations on 40 gulls (Larus), 15 eiders (Somateria) and some birds of shelduck (Tadorna), curlew (Numenius), oystercatcher (Haematopus) and terns (Sterna) resulted all in all 7 coccidia and about 76 helminth species, partly residenting in different hosts and often in enormous quantities (Somateria 160.000, Tadorna 58.000, Larus 62.000, Numenius 93.000). Effects of helminthal loads upon the avian hosts, biology of parasites and correlations between their coastal and inland places of residence are in discussion. Morphological differences of Psilochasmus in Tadorna tadorna, of Gymnophallus from gallbladders of Larus too, furthermore the structural change of egg-forming Gymnophallida in the gut of Somateria mollissima and coccid oocysts from kidneys of Larus argentatus, Haematopus ostralegus, Tadorna tadorna and Somateria mollissima are showed.     

Gastrointestinal helminths of little blue penguins,Eudyptula novaehollandiae (Stephens), from Otago,New Zealand

Data regarding helminth communities can provide insights into health, feeding interactions, behaviour and evolution of their host organisms. Penguins (Spheniscidae) are important components of marine food webs and tracking their helminth communities can be indicative of ecosystem health. New Zealand is home to 5 of the world's 19 penguin species and little is known about their gastrointestinal helminths. Here, we provide the first study on the gastrointestinal helminths of little blue penguins from south-eastern South Island, New Zealand. The helminth community consisted of two species of tapeworm; Tetrabothrius lutzi and Tetrabothrius sp.; three nematode species, Contracaecum eudyptulae, Capillaria sp. and Stegophorus macronectes; two acanthocephalans, Andracantha sigma and Bolbosoma balaenae; and one trematode, Galactosomum otepotiense. The most prevalent parasites were T. lutzi, A. sigma, and C. eudyptulae. This work includes three new host records and five new geographic records. This is the first report of B. balaenae occurring in a host other than a marine mammal. This study adds to our knowledge about the helminth community of New Zealand little blue penguins, and includes new genetic data on helminth species, providing a baseline against which future studies may be compared.     

Gastrointestinal helminths in brown trout (Salmo trutta Linnaeus, 1758) captured in Galician rivers (NW Spain)

Specimens of Salmo trutta (n = 613) captured by local anglers in different rivers in Galicia (NW Spain) during the 2015 fishing season (15 March–15 August) were examined. In total 1479 adult helminths were recovered from the gastrointestinal tracts of 221 fish. Moreover, the microscopic observation of the sediments obtained, previous diphasic concentration, revealed the presence of helminth eggs in 485 trout specimens. The following species were identified by morphological and molecular analysis: Crepidostomum metoecus (8.97%) (Trematoda); Salmonema ephemeridarum (16.97%), Raphidascaris acus (9.46%) and Pseudocapillaria sp. (2.12%) (Nematoda); and Echinorhynchus truttae (8.48%) (Acanthocephala). The prevalence, mean intensity and mean abundance of each helminth species were determined in relation to size/age of the fish. The helminth infracommunity comprised a maximum of four species and the species richness was S = 5. The biological cycles of most of the helminth species recovered are dependent on benthic macroinvertebrate fauna, which, in turn, is influenced by the water quality. Therefore, any changes that take place in the aquatic ecosystem (due to anthropogenic activities or climate change) may be reflected in the helminth composition.     

Helminth communities in the burrowing toad, Rhinella fernandezae, from Northeastern Argentina

The main goals of this study were to determine the richness and diversity of helminth parasites of Rhinella fernandezae at the component and infracommunity levels and determine the ecological implications of different biotic and abiotic factors. Specimens were collected near the city of Corrientes, Corrientes Province, Argentina. Prevalence of infection was 94% in the specimens examined (n = 65). The helminth component community in R. fernandezae in this area was comprised a total of 22 species. Of all helminth species, only three (Catadiscus inopinatus, Cosmocerca podicipinus and C. parva) were dominant (importance value: I > 1.0) in the community. The most abundant species were B. tetracotyloides (d = 0.43) among the larvae and C. podicipinus (d = 0.09) among adult worms. At the infracommunity level, the mean individual species richness (2.28 ± 1.48) (mean ± SD) was no more than 3 helminth species per infected host; the diversity and equitability of helminths were 0.23 ± 0.21 and 0.48 ± 0.38, respectively. The host body size was the main factor in determining the parasite abundance. Species richness was significantly and positively correlated with host body size. The parasite helminth species predominantly showed an overdispersed pattern of distribution. Helminth species showed two negative and significant pairs of covariation and one significant pair of association (P < 0.05). R. fernandezae has a wide variety of parasites relating to the host microhabitat, mobility and feeding habits.     

Trematodes Recovered in the Small Intestine of Stray Cats in the Republic of Korea

In 2005, we reported the infection status of 438 stray cats with various species of intestinal helminths, including nematodes (4 species), trematodes (23 species), and cestodes (5 species) in the Republic of Korea. However, morphologic details of each helminth species have not been provided. In the present study, we intended to describe morphologic details of 13 trematode species which were either new fauna of cats (10 species) or new fauna of not only cats but also all animal hosts (3 species). The worms were fixed in 10% neutral buffered formalin under a cover slip pressure, stained with Semichon''s acetocarmine, and then observed using a light microscope equipped with a micrometer. The 13 subjected species included members of the Heterophyidae (Stellantchasmus falcatus, Stictodora fuscata, Stictodora lari, Centrocestus armatus, Procerovum varium, and Cryptocotyle concava), Echinostomatidae (Echinostoma hortense, Echinostoma revolutum, Echinochasmus japonicus, and Stephanoprora sp.), Diplostomidae (Neodiplostomum seoulense), Plagiorchiidae (Plagiorchis muris), and Dicrocoeliidae (Eurytrema pancreaticum). By the present study, Cryptocotyle sp. and Neodiplostomum sp. recored in our previous study were identified as C. concava and N. seoulense, respectively. Three species, P. varium, C. concava, and Stephanoprora sp., are new trematode fauna in Korea.