Helminth community structure of sympatric eastern American toad, Bufo americanus americanus, northern leopard frog, Rana pipiens, and blue-spotted salamander, Ambystoma laterale, from southeastern Wisconsin

One-hundred twelve amphibians, including 51 blue-spotted salamanders, Ambystoma laterale, 30 eastern American toads, Bufo americanus americanus, and 31 northern leopard frogs, Rana pipiens, were collected during April-October 1996 from Waukesha County, Wisconsin and examined for helminth parasites. The helminth compound community of this amphibian assemblage consisted of at least 10 species: 9 in American toads, 8 in leopard frogs, and 3 in blue-spotted salamanders. American toads shared 7 species with leopard frogs, and 2 species occurred in all 3 host species. Although there was a high degree of helminth species overlap among these sympatric amphibians, statistically significant differences were found among host species and percent of indirect or direct-life cycle parasites of amphibian species individual component communities (chi2 = 1,015, P < 0.001). American toads had a higher relative abundance of nematodes, 59%, than larval cestodes, 31%, and larval and adult trematodes, 10%, whereas leopard frogs had a higher relative abundance of larval cestodes, 71.3%, and larval and adult trematodes, 25.3%, than nematodes 3.4%. This is related to ecological differences in habitat and dietary preferences between these 2 anuran species. Helminth communities of blue-spotted salamanders were depauperate and were dominated by larval trematodes, 94%, and few nematodes, 6%. Low helminth species richness in this host species is related to this salamander's relatively small host body size, smaller gape size, lower vagility, and more fossorial habitat preference than the other 2 anuran species. Adult leopard frogs and toads had significantly higher mean helminth species richness than metamorphs, but there was no significant difference in mean helminth species richness among adult and metamorph blue-spotted salamanders. Considering adult helminths, the low species richness and low vagility of caudatans as compared with anurans suggest that local factors may be more important in structuring caudatan helminth communities of salamanders than of anuran hosts. Helminth species infecting salamanders may be more clumped in their geographic distribution as compared with anurans, and the role of other hosts and their parasites at the compound community level may be important in structuring helminth communities of salamanders.     

Helminth risks associated with mixed game and livestock interactions in and around Lake Mburo National Park, Uganda

A study was performed in and around Lake Mburo National Park (LMNP) to identify common helminths that parasitize both game and livestock. Various techniques including floatation, Baerman and sedimentation tests, faecal culturing and post‐mortem were used to identify helminths recovered during the survey. Identification was based on egg, larval and adult helminth developmental stages. Results showed that 22 species of parasitic nematodes, lungworms, ascaris, trematodes and tapeworms occur in both wild game and livestock found in and around the national park. The significance of the findings to helminth cross‐infection among game, livestock and man is discussed.     

Helminth communities of native and introduced fishes in Lake Pátzcuaro, Michoacán, México

In Lake Pátzcuaro in the Mesa Central of México, a total of 19 species of helminths was found in 598 fishes and comprised five digeneans, two monogeneans, four cestodes, one acanthocephalan and seven nematodes, of which ten species were represented by larval or immature states. The richest and most diverse helminth communities were found in the native carnivorous goodeid Alloophorus robustus. In general, the helminth communities in the different fish species were not particularly species rich and the parasite assemblages were numerically dominated by larvae of the bird trematode, Posthodiplostomum minimum. Patterns of helminth community richness and diversity were similar to those previously observed in north-temperate freshwater fishes. Most enteric helminths occurred with low abundance and only a small proportion of the gut helminth communities was numerically dominated by any one species. Helminths dominating their enteric communities showed some level of host specificity. Helminth communities in carnivorous fish species were generally richer than those in herbivores and detritivores, with the exception of the predominantly herbivorous Goodea atripinnis. The helminth fauna of introduced fishes, Cyprinus carpio, Micropterus salmoides and Oreochromis niloticus , consisted of either few or no host-specific adult helminth(s) translocated from their original geographical areas and by larval stages of helminths of piscivorous birds. Based on the geological history of the area and the biogeography of the endemic fish fauna, it is hypothesized that host-switching and relationships with the nearctic fauna have been fundamental in determining the helminth fauna of the endemic fish hosts.     

Helminth and leech community structure in tadpoles and caudatan larvae of two amphibian species from Western Nebraska

Currently no comparative studies exist on helminth and leech community structure among sympatric anuran tadpoles and salamander larvae. During June-August 2007-2009, we examined 50 bullfrog tadpoles, Rana catesbeiana , 50 barred tiger salamander larvae, Ambystoma mavortium , and 3 species of snails from Nevens Pond, Keith County, Nebraska for helminth and leech infections. The helminth and leech compound community of this larval amphibian assemblage consisted of at least 7 species, 4 in bullfrog tadpoles and 4 in barred tiger salamander larvae. Bullfrog tadpoles were infected with 2 species of nematodes ( Gyrinicola batrachiensis and Spiroxys sp.) and 2 types of metacercariae ( Telorchis sp. and echinostomatids), whereas barred tiger salamander larva were infected with 1 species of leech ( Placobdella picta ), 2 species of adult trematodes ( Telorchis corti and Halipegus sp.), and 1 species of an unidentified metacercaria. The component community of bullfrog tadpoles was dominated by helminths acquired through active penetration, or incidentally ingested through respiratory currents, or both, whereas the component community of larval salamanders was dominated by helminths acquired through ingestion of intermediate hosts (χ2 = 3,455.00, P < 0.00001). Differences in amphibian larval developmental time (2-3 yr for bullfrog tadpoles versus 2-5 mo for salamander larvae), the ephemeral nature of intermediate hosts in Nevens Pond, and the ability of bullfrog tadpole to eliminate echinostome infections had significant effects on mean helminth species richness among amphibian species and years (t = 12.31, P < 0.0001; t = 2.09, P = 0.04). Differences in herbivorous and carnivorous diet and time to metamorphosis among bullfrog tadpoles and barred tiger salamander larvae were important factors in structuring helminth communities among the larval stages of these 2 sympatric amphibian species, whereas size was important in structuring helminth and leech communities in larval salamanders, but not in bullfrog tadpoles.     

Latitudinal gradient in the taxonomic composition of parasite communities

Although latitudinal gradients in diversity have been well studied, latitudinal variation in the taxonomic composition of communities has received less attention. Here, we use a large dataset including 950 surveys of helminth endoparasite communities in 650 species of vertebrate hosts to test for latitudinal changes in the relative contributions of trematodes, cestodes, nematodes and acanthocephalans to parasite assemblages. Although the species richness of helminth communities showed no consistent latitudinal variation, their taxonomic composition varied as a function of both host type and latitude. First, trematodes and acanthocephalans accounted for a higher proportion of species in helminth communities of fish, whereas nematodes achieved a higher proportion of the species in communities of bird and especially mammal hosts. Second, the proportion of trematodes in helminth communities of birds and mammals increased toward higher latitudes. Finally, the proportion of nematodes per community increased toward lower latitudes regardless of the type of host. We present tentative explanations for these patterns, and argue that new insights in parasite community ecology can be gained by searching for latitudinal gradients not only in parasite species richness, but also in the taxonomic composition of parasite assemblages.     

Helminth infracommunities of the frogs Rana catesbeiana and Rana clamitans from Turkey Marsh, Michigan

One hundred twenty-seven bullfrogs, Rana catesbeiana, and 120 green frogs, Rana clamitans, collected in July and August 1987 from Turkey Marsh, Michigan, were examined for helminths. Of the 16 helminth species found, Falcaustra catesbeianae had the highest prevalence and mean intensity in bullfrogs. In green frogs, Megalodiscus temperatus had the highest prevalence and Haematoloechus parviplexus had the highest mean intensity. Taxonomically, 1,030 (30.5%) trematodes and 2,348 (69.5%) nematodes occurred in bullfrogs; 2,874 (96.4%) trematodes, 2 (0.1%) cestodes, and 105 (3.5%) nematodes were found in green frogs. The larger and more aquatic of the 2 hosts, R. catesbeiana, had the highest mean number of helminth species, helminth intensity, diversity, and evenness. Adult frogs of both species had a significantly higher mean number of helminth species than did juveniles. Significant correlations existed between the number of helminth species and frog length. Although the helminth communities of Turkey Marsh frogs are isolationist in character, they are more diverse than other helminth communities studied in amphibians.     

洞庭湖外睾吸虫新种及其生活史

本文报告洞庭湖区鲶鱼肠道寄生的洞庭湖外睾吸虫Exorchis dongtinghuensis sp.nov(新种)及其全程生活史,其第一中间宿主为湖北钉螺Oncomelania hupensis;第二中间宿主为鲤鱼、鲫鱼和金鱼;终宿主为鲶鱼Parasilurus asotus。作者对各期宿主作了人工感染试验和现场自然感染调查。对其发育过程作了观察比较。     

Helminthic fauna of commercial fishes from the Saya-de-Malya bank (Indian Ocean)

The data on infestation of 8 species of commercial fishes from Saya-de-Malya bank (the Indian Ocean) are presented. 43 helminth species were identified: 10 Monogenea species, 18 trematode, 7 cestode and 8 nematode species. The mature worms are observed to be related to a certain host, whereas the nematode and cestode larvae have wide specificity. High infestation degree by Anisakis larvae is found in fishes, especially in Carangidae. At the bank area fishes are found to be free from Acanthocephala while those Acanthocephala are found in fishes from other areas of the Indian Ocean which may be attributed to the specific diet at the Saya-de-Malya bank. On the whole the helminth fauna of fishes examined at the Saya-de-Malya bank does not demonstrate the endemic pattern. The most specific helminth species were found in some fish species.     

Parasitism in the bathypelagic fish, Melanostigma pammelas

Three hundred and thirty-seven specimens of the zoarcid fish, Melanostigma pammelas, collected between December, 1950 and December, 1969 from bathypelagic waters off southern California, were examined for their parasites. Incidences of infection were: digentic Trematoda 61%, Myxosporida 39%, larval Nematoda 9%. Two adult trematodes are described: Fellodistomum melanostigmum nov. sp. from the intestine, and Aponurus pacificus nov. sp. from the stomach. This parasite record is markedly unlike the typical record reported for eastern Pacific mesopelagic fishes in which many larval nematodes and few, if any, adult trematodes were found. Our long-term objective is to explain parasite pattern differences in the deep ocean in terms of their biological and physical environments. Our initial purpose is to determine the numbers and kinds of parasites in M. pammelas.     

Helminths of the ocelot from southern Texas

In the USA, the ocelot (Leopardus pardalis) is a highly endangered felid found only in a few remaining vestiges of native thornshrub brushland in the Lower Rio Grande Valley (LRGV) of extreme southern Texas. From 1987-1998, carcasses of 15 adult ocelots that died of vehicular accidents or natural causes were examined for helminths. All cats had 1-8 (mean = 3) helminth species. All were infected with 1-101 (mean +/- SE = 32 +/- 7) Toxascaris leonina. Other helminths from these ocelots were Alaria marcianae, Brachylaima sp., Mesocestoides lineatus, Taenia rileyi, Oncicola canis, Dirofilaria immitis, Physaloptera rara, Ancylostoma tubaeformae, Cylicospirura chevreuxi, Vogeloides felis, and Metathelazia californica. Additionally, two cats had scarring of the aorta with lesions typical of those caused by Spriocerca lupi, although larval nematodes were not seen. A clinal variation in size of nearly three orders of magnitude was noted in the diplostomatid trematodes in the small intestine of one adult male ocelot. Despite the differences in size, all specimens appeared morphologically identical and were regarded as A. marcianae. Helminth prevalences and abundances, including those of potentially pathogenic species like D. immitis, were low. Although a single heartworm infection may have contributed to the death of one ocelot, helminth infections in general seemed to be of no great consequence to this endangered ocelot population. The helminth fauna of ocelots in the LRGV is reflective of that from wild felids in general; all have been reported previously from the bobcat (Lynx rufus) and mountain lion (Puma concolor) elsewhere in Texas.     

Studies on the helminth parasites of the Long-tailed field mouse, Apodemus sylvaticus sylvaticus from Wales

The incidence and degree of infestation of the Long-tailed field mouse, Apodemus sylvaticus with helminth parasites have been studied from a rough grassland and woodland area, Aberystwyth and from Skomer Island in Wales. With few exceptions, adult mice were more heavily infested than juveniles.
In Aberystwyth, where the composition of the helminth fauna was found to be more varied than that from the island of Skomer, three species of helminths, one digenean and two nematodes, showed evidence of seasonal variation in the degree of infestation of mice. The factors affecting this fluctuation in parasite numbers throughout the year are discussed.
It is suggested the distribution of helminths in the mouse population may be represented by a negative binomial, indicating that the infective eggs, larvae or intermediate hosts of the respective helminths were aggregated in their distribution in the selected areas of study.     

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 role of the rock cod Notothenia coriiceps Richardson, 1844 in the life-cycle of Antarctic parasites

Fifty specimens of Notothenia coriiceps caught in Potter Cove, King George Island, were examined for ecto- and endoparasites. Of the 22 parasite species found, 18 were helminths, 2 were hirudineans and 2 were crustaceans. The isopod Aega antarctica and an unidentified hirudinean are reported for the first time from this fish host. Dominant parasites were the adults of Aspersentis megarhynchus, the invasive stage of Corynosoma spp. (cystacanth) and the adults of Macvicaria pennelli, with respective prevalences of infestation of 94, 76 and 74%. The preferred sites of infestation were the pylorus and intestine, where five different larval (nematodes and cestodes) and eight adult (digeneans and acanthocephalans) parasite species were found. No adult nematodes and cestodes were found and no parasites could be isolated from the musculature. The results of the present study are related to previous findings on the parasite fauna of N. coriiceps. The comparison implies a high parasite diversity in this benthic Antarctic fish species. Most parasites found appear to have a wide range of distribution within Antarctic waters together with a low host specificity. Besides its role as final host for several species of trematodes and acanthocephalans, N. coriiceps serves as transmitter of parasite larvae to piscivorous birds and seals. It is concluded that the parasite fauna in Antarctic fish species provides important insights into the different habitat use and trophic relationship of their fish hosts. Received: 11 September 1997 / Accepted: 12 January 1998     

Helminth assemblages of the turtle Emydura macquarii (Pleurodira: Chelidae) Queensland, Australia

The helminth fauna of 76 Emydura macquarii from 3 river systems in central and northern Queensland was examined. Eleven species were found, including 2 nematodes, 6 trematodes, 1 aspidogastrean, 1 cestode, and 1 monogenean. Analysis of helminth diversity showed that the Fitzroy and Ross River turtles had communities of comparable diversity, but the helminth communities in Proserpine River turtles were much less diverse. The helminth communities in all localities were dominated by trematodes. Polystomoides australiensis was the most prevalent, being found in 60% of the Ross River turtles, 57% of the Fitzroy River turtles, and 46% of the Proserpine River turtles. Notopronocephalus peekayi was the most abundant species, with mean abundances of 5.9 in the Ross River turtles and 9.8 in the Fitzroy River turtles. Species richness, Simpson's Reciprocal Index, was highest, 4.68, for the Ross River helminth community, Sorensen's Qualitative Index showed 95% similarity between the Ross River and Fitzroy River communities, although Sorensen's Quantitative Index indicated only 35% similarity between the 2 sites. Host feeding patterns are likely the most important factor affecting species richness of the helminth infracommunities, as the majority of helminth species are transmitted by food-web interactions involving intermediate hosts.     

Helminthofauna of the common shrew Sorex araneus L. (Soricidae) from Samarskaya Luka

Ecological analysis of the helminthofauna of common shrew Sorex araneus L. from Samarskaya Luka (Samara Region) has been carried out. Twenty-three helminth species are found including 3 species of trematodes, 8 cestodes, 10 nematodes, and 2 acanthocephales. Dependence of the structure of helminthofauna on the host age is revealed.     

Parasitic helminths of flying starlings (Sturnus vulgaris L.) in their nesting area

1.150 flying starlings and 226 pulli have been necropsied and their helminth parasites collected. Localities where the birds has been captured are given in table 1 and the map. Flying birds are parasited in the proportion of 97.1%. There are three trematodes species, eight cestodes, six nematodes and one acanthocephalan (table 2). Differences are noted according with the locality, the season and the age of the bird. Pulli are parasited by 47% with a very important difference between the two places. The number of parasitic species is lesser: one trematode, two cestodes and three nematodes. The helminthological fauna of belgian starlings seems common but more important and much varied that in the birds hibernating in North Africa.     

The helminth fauna of wild and domestic ruminants in Mongolia—a review

The helminth fauna of eight species of wild ruminants and five species of domestic ruminants sharing common grassland in Mongolia was reviewed. A total of 108 species of helminths, belonging to 40 genera, 23 families, 11 superfamilies, 6 orders and 3 classes were reported in wild and domestic ruminants in Mongolia. Several new host–helminth associations have been recorded. Twenty seven helminth species have been found in certain host species for the first time in Mongolia. These included 2 species of trematodes, 2 species of cestodes and 23 species of nematodes. Helminths that are specific for some of the examined ruminant species were determined. However, wild animals may serve as a reservoir of helminth infections for domestic animals when sharing grassland in Mongolia. The helminth fauna of the ruminants with respect to occurrence, distribution, prevalence and intensity of infection was considered for six geographic regions of Mongolia.     

Helminth fauna of Talpa spp. in the Palaearctic Realm

The helminth fauna of the genus Talpa in the Palaearctic Realm is reviewed. Several helminth species reported in Talpa spp. by a number of authors are discussed, with reference to host specificity, parasite biology, and host ethology, ecology and phylogeny. Twelve species of cestodes were found, two of which exhibit stenoxenous specificity (Staphylocystis bacillaris and Multitesticulata filamentosa). Only three species of trematodes, Ityogonimus lorum, Ityogonimus ocreatus and Combesia macrobursata, are exclusive parasites of Talpa spp. The largest group are nematodes, with 37 species. Species of Tricholinstowia are parasites of holarctic talpids and several species of distinct genera, such as Capillaria, Soboliphyme and Trichuris, are found only in Talpa spp. Only acanthocephalans of the genus Moniliformis have been reported in moles of the genus Talpa. On the basis of these helminthological findings, the close phylogenetic relationship between moles (Talpidae) and shrews (Soricidae) supports the separation of the ordinal levels Soricomorpha and Erinaceomorpha.     

Intestinal helminths of capybaras, Hydrochoerus hydrochaeris, from Venezuela

Quantitative parameters of intestinal helminth species and their potential relations to host characteristics in a population of capybaras (Hydrochoerus hydrochaeris) from Venezuela are reported for the first time. The intestines of 40 capybaras were collected during the 1992-annual harvest at Hato El Cedral. Six helminth species were found: 2 cestodes (Monoecocestus macrobursatum, M. hagmanni), 2 nematodes (Viannella hydrochoeri, Protozoophaga obesa), and 2 trematodes (Hippocrepis hippocrepis, Taxorchis schistocotyle). This is the first report for M. macrobursatum in Venezuela. Helminth abundance did not differ between sexes or age classes. Although patterns of distribution for all helminth species were overdispersed, the high prevalence found for all species (over 70%) and the high abundance observed for nematodes made it difficult to assess the effect that these helminths may produce on capybaras. Nevertheless, the negative associations found between the body condition of capybaras and helminth intensity for M. macrobursatum and V. hydrochoeri, might be pointing out potential host population regulatory role for these parasites which require further research.     

A comparative analysis of the helminth fauna of kittiwake Rissa tridactyla (Linnaeus, 1758) and glaucous gull Larus hyperboreus Gunnerus, 1767 from different parts of the Barents Sea

The article is based on the results of helminthological observations made on kittiwake Rissa tridactyla and glaucous gull Larus hyperboreus in 1991-2001 in different areas of the Barents Sea (Eastern Murman coast, Franz Josef Land, Novaya Zemlya, Spitzbergen). 18 helminth species (2 trematodes, 11 cestodes, 4 nematodes, and 2 acanthocephalans) were recorded in the kittiwakes and 19 (3 trematodes, 9 cestodes, 5 nematodes and 2 acanthocephalans) species were recorded in the glaucous gulls. Trematodes were absent in the birds collected at the Franz Josef Land and the northern island of Novaya Zemlya. 3 trematode species, namely Gymnophallus sp. (somateria?), Microphallus sp. 1 (M. pseudopygmaeus), and Cryptocotyle lingua were found in the glaucous gulls of western Spitzbergen. It was supposed that the life cycles of these parasites can be completed there. On the other hand, coastal ecosystems of Arctic archipelagoes turn out to be favourable for the transmission of some cestodes. This is closely connected with the regional traits in the marine bird diet, namely the increase of the amphipod (intermediate hosts of hymenolepidids and some dilepidids) and polar cod (supposed second intermediate host for some tetrabothriids) portion in Arctic. As a result, cestodes are the base of the helminth fauna of kittiwakes and glaucous gulls of the Barents Sea, by their species richness, prevalence and abundance. Nematodes and acanthocephalans were represented by a few species with low infection intensity. The main ecological factors affected the regional difference in the species richness and abundance of the helminths parasitising kittiwakes and glaucous gulls in the Barents Sea are proposed. Those are regional climatic features and regional traits in the behaviour and food priorities of birds, and also the distribution of the helminths intermediate hosts, invertebrates and fishes. The phenomenon of host specificity lowering with respect to the definitive host was recorded in some cestode species (Microsomacanthus diorchis, M. microsoma, and Arctotaenia tetrabothrioides) on the border of their distribution ranges, the coastal ecosystems of Arctic.