Host specificity and exchange of intestinal helminths among four species of grebes (Podicipedidae)

1987 ◽  
Vol 65 (3) ◽  
pp. 669-676 ◽  
Author(s):  
T. M. Stock ◽  
John C. Holmes

The infracommunities of intestinal helminths in 96 birds belonging to four species of grebes taken from lakes in Alberta were examined for patterns of species co-occurrence and relative abundance. Infracommunities were large (averages of 360–3640 worms) and complex (averages of 6.4–10.7 species). Three species of grebes (Aechmophorus occidentalis, Podiceps grisegena, P. nigricollis) had distinctive infracommunities, each characterized by a set (5–10) of frequent and numerous core helminth species, which regularly co-occurred with a consistent rank order of numbers. Infracommunities in Podiceps auritus overlapped those of the other two species of Podiceps and had few (2) core species. Most (11 of 14) core species are specialists in grebes, but only one was limited to a single host species. Most were shared among hosts, with the bulk of the population of each occurring in one host species. Sharing was particularly significant between the large, fish-eating grebes (A. occidentalis and P. grisegena) and between the smaller, mainly invertebrate-eating grebes (P. nigricollis and P. auritus). Host specificity and the pattern of exchange of helminths, mediated by the differentiated but overlapping host food habits, were important determinants of enteric helminth community structure.

2002 ◽  
Vol 50 (6) ◽  
pp. 597 ◽  
Author(s):  
I. Beveridge ◽  
N. B. Chilton ◽  
D. M. Spratt

The occurrence of species flocks within the nematode genus Cloacina was examined using the criteria of host specificity, co-occurrence and monophyly. Species of Cloacina generally exhibited a high degree of host specificity, with most species occurring either in a single host species or in two closely related host species. The frequency distribution of numbers of component species of Cloacina per host species indicated that most host species harboured 2–4 species of nematodes, with an approximately exponential decline in the number of species of parasites to a maximum of 20 species of nematode per host species. Host species harbouring eight or more species of Cloacina were found within a single recent macropodid clade, but there was no correlation between evolutionary age of the host and the number of parasite species harboured. Sampling effort was significantly correlated with the number of nematode species found and, in partial regression analysis, subsumed the effects of host body size and geographic range, which were found to be significant correlates with the number of nematode species present in preliminary analyses. Analysis of co-occurrences of nematode species indicated significant variation between host species, with some hosts (e.g. Macropus agilis) most commonly harbouring a single species of Cloacina, while closely related host species (e.g. M. dorsalis) most commonly harboured numerous species. Parsimony analysis of species of Cloacina based on morphological data suggested that while small series of related nematode species could be identified within a single host species, the species flock in each host species is polyphyletic in origin. Species flocks contributed significantly to community richness in some host species.


1986 ◽  
Vol 64 (1) ◽  
pp. 142-152 ◽  
Author(s):  
Albert O. Bush ◽  
John C. Holmes

This paper examines patterns in the linear distribution of helminths in the small intestine of each of 45 scaup. Over all birds, most common species of helminths were found in over half of the small intestine; their distributions overlapped broadly. In individual birds, each species occupied a more restricted, predictable part of the intestine; "core species" (those present in more than two-thirds of the birds) were more evenly distributed along the intestine than expected by chance and occupied almost all of it; "secondary species" (those in one- to two-thirds of the birds) were clumped in anterior and posterior portions of the intestine; and "satellite species" (those in less than one-third of the birds) were randomly distributed. For all common helminths, the range occupied in individual birds was significantly correlated with population size; however, overlap between adjacent species did not increase with increases in their total numbers. The intestinal helminths of scaup belonged to three guilds: small absorbers (paramucosal), large absorbers (mid-lumenal), and trematodes. The interactions noted above occurred both within and between guilds. The overall helminth community in scaup appeared to be saturated with species belonging to the two absorber guilds, but not with trematodes. Communities within individual scaup sampled this overall community and were often unsaturated. We conclude that the core and secondary species of absorbers provide a basic, interactive structure to the overall community and to most of the communities in individual birds. Trematodes and satellite absorber species provide stochastic elaborations.


Parasitology ◽  
2019 ◽  
Vol 147 (2) ◽  
pp. 213-224 ◽  
Author(s):  
Ronel Pienaar ◽  
Antoinette Josemans ◽  
Abdalla A. Latif ◽  
Ben J. Mans

AbstractTick-borne diseases caused by Theileria are of economic importance in domestic and wildlife ruminants. The majority of Theileria infects a limited number of host species, supporting the concept of host specificity. However, some Theileria seem to be generalists challenging the host specificity paradigm, such as Theileria sp. (sable) reported from various vertebrate hosts, including African buffalo, cattle, dogs and different antelope species. We tested the hypothesis that T. sp. (sable) uses Bovidae as hosts in general using a real-time polymerase chain reaction assay specific for T. sp. (sable) and a closely related genotype: T. sp. (sable-like). Various antelope species from the Tragelaphini (black wildebeest, blesbuck, blue wildebeest, gemsbuck, sable and waterbuck) tested positive for either T. sp. (sable) or T. sp. (sable-like). However, no African buffalo (n = 238) or cattle (n = 428) sampled in the current study tested positive, suggesting that these latter species are not carrier hosts. The results were confirmed using next-generation sequencing which also indicated at least 13 new genotypes or species found in various antelope and giraffes. Genotypes were found in single host species or in evolutionarily related hosts, suggesting that host specificity in Theileria may be a lineage specific phenomenon likely associated with tick-host-parasite co-evolution.


1997 ◽  
Vol 24 (4) ◽  
pp. 445 ◽  
Author(s):  
L. R. Smales ◽  
T. H. Cribb

The helminth fauna from 124 water-rats, Hydromys chrysogaster, collected from 33 localities in Queensland was analysed. A total of 45 species of helminths was found, comprising 2 acanthocephalans, 2 cestodes, 13 nematodes and 28 trematodes. The helminth community of the water-rats in the region north of latitude 18˚ (far north) was different from that of water-rats south of 18˚ (central); Sorensen’s Index 45·8% similarity, whereas Holmes and Podesta’s Index gave 32·1% similarity. Comparisons with data from water-rats from southern and Tasmanian regions showed that they were different from each other and from both Queensland regions. The helminth communities were characterised by high diversity, dominated by trematodes in the central and Tasmanian regions, but with nematodes becoming more prominent in the far northern and southern regions. No core or secondary species were found in the Queensland helminth communities, the southern community was suggestive of a bimodal distribution and the Tasmanian had two core species. A checklist of helminth species occurring in water-rats from eastern Australia is provided.


Oryx ◽  
2014 ◽  
Vol 49 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Lajos Rózsa ◽  
Zoltán Vas

AbstractThe co-extinction of parasitic taxa and their host species is considered a common phenomenon in the current global extinction crisis. However, information about the conservation status of parasitic taxa is scarce. We present a global list of co-extinct and critically co-endangered parasitic lice (Phthiraptera), based on published data on their host-specificity and their hosts’ conservation status according to the IUCN Red List. We list six co-extinct and 40 (possibly 41) critically co-endangered species. Additionally, we recognize 2–4 species that went extinct as a result of conservation efforts to save their hosts. Conservationists should consider preserving host-specific lice as part of their efforts to save species.


Parasitology ◽  
2007 ◽  
Vol 134 (10) ◽  
pp. 1465-1476 ◽  
Author(s):  
I. BEVERIDGE ◽  
S. SHAMSI ◽  
M. HU ◽  
N. B. CHILTON ◽  
R. B. GASSER

SUMMARYGenetic variation was examined in the anoplocephalid cestode Progamotaenia festiva, from Australian marsupials, in order to test the hypothesis that P. festiva, is a complex of sibling species and to assess the extent of host switching reported previously based on multilocus enzyme electrophoresis (MEE). Polymerase chain reaction (PCR)-based single-strand conformational polymorphism (SSCP) was used for the analysis of sequence variation in the cytochrome c oxidase subunit 1 (cox1) gene among 179 specimens of P. festiva (identified based on morphology and predilection site in the host) from 13 different host species, followed by selective DNA sequencing. Fifty-three distinct sequence types (haplotypes) representing all specimens were defined. Phylogenetic analyses of these sequence data (utilizing maximum parsimony and neighbour-joining methods) revealed 12 distinct clades. Other heterologous species, P. ewersi and P. macropodis, were used as outgroups and the remaining bile-duct inhabiting species, P. diaphana and P. effigia, were included in the analysis for comparative purposes. The latter 2 species were nested within the clades representing P. festiva. Most clades of P. festiva identified were restricted to a single host species; one clade primarily in Macropus robustus was also found in the related host species M. antilopinus in an area of host sympatry; another clade occurring primarily in M. robustus occurred also in additional kangaroo species, M. rufus and M. dorsalis. High levels of genetic divergence, the existence of distinct clades and their occurrence in sympatry provide support for the hypothesis that P. festiva represents a complex of numerous species, most of which, but not all, are host specific. Three distinct clades of cestodes were found within a single host, M. robustus, but there was no evidence of within-host speciation.


2014 ◽  
Vol 104 (3) ◽  
pp. 295-306 ◽  
Author(s):  
M.E. Barrantes ◽  
M.K. Castelo

AbstractLarvae of the robber flyMallophora ruficaudaare ectoparasitoids of white grubs and adults are an important apiculture pest in Argentina. Females oviposit on tall grasses and the second instar larva actively searches and locates hosts. There are nine potential hosts in the distribution area of this parasitoid andCyclocephala signaticollis(Coleoptera: Scarabaeidae) is the most parasitized in the field. However,M. ruficaudahas a certain degree of behavioural flexibility towards different host species, and not being a strict specialist. The conditions under which the parasitoid orientates and accepts different hosts’ species are unknown. We studied the host specificity ofM. ruficaudatowards three species ofCyclocephalagenus and we determined whether this specificity depends on larval age. We also evaluated whether larva orientation towardsCyclocephalaspecies changes with chemical cue concentration. We assessed host specificity measuring the orientation and acceptance behaviours towards kairomones extracts and live individuals ofCyclocephalaspecies usingM. ruficaudalarvae of low and high life expectancy (i.e., young and aged second instar larvae). We observed that young larvae orientated only towardsC. signaticollischemical stimulus, whereas aged larvae orientated also towardsC. modesta, and the same was observed with increasing stimuli's concentration. Both young and agedM. ruficaudalarvae orientate towards liveC. signaticollisandC. putridaspecies and rejectedC. modesta. Also, we found that larvae accepted allCyclocephalahosts. In conclusion, our results indicate that specificity in the laboratory, observed through host orientation and host acceptance behaviours, depends not only on the availability of host species, but also on the nature of the host's stimuli combined with parasitoid age.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jason M. Garvon ◽  
Alan M. Fedynich ◽  
Markus J. Peterson ◽  
Danny B. Pence

The influence of spatially distinct host subpopulations on helminth community structure and pattern was examined in a migratory avian host species. Forty helminth species represented by 24,082 individuals were collected from 184 blue-winged teal (Anas discors; BWT) from 2 primary migratory corridors in Florida (eastern migratory corridor; EMC) and Louisiana and Texas (western migratory corridor; WMC). Mean species richness was greater in BWT from the WMC (x¯±S.E=10.2 ± 0.3species) than the EMC (8.6 ± 0.2). The helminth community from the WMC had higher abundances of 6 common/intermediate species. Corridor helminth communities were similar in species composition but less similar when incorporating abundances of those species. Overlapping distributions of phylogenetically related host species that share generalist helminth species across ecologically similar habitats seem to mitigate the isolating mechanisms that are necessary for the distinct coevolutionary pathways to develop between adjacent corridors.


Author(s):  
Wei Wang ◽  
Lance A Durden ◽  
Haylee Weaver ◽  
Renfu Shao

Abstract Based on a comprehensive study of museum specimens, eight new species of sucking lice of the genus Hoplopleura Enderlein, 1904 (Psocodea: Phthiraptera: Hoplopleuridae), are described from six genera of Australian Old Endemic rodents: Conilurus Ogilby, 1838 (Rodentia: Muridae), Leggadina Thomas, 1910 (Rodentia: Muridae), Leporillus Thomas, 1906 (Rodentia: Muridae), Mesembriomys Palmer, 1906 (Rodentia: Muridae), Pogonomys Milne-Edwards, 1877 (Rodentia: Muridae), and Xeromys Thomas, 1889 (Rodentia: Muridae). The description of these new species increases the number of sucking louse species from endemic Australian rodents from 13 to 21 and extends the records of sucking lice to all of the 14 genera of endemic rodents in Australia. Our results show that sucking lice are much more diverse among rodents in Australia than previously known. Furthermore, the Australian Hoplopleura species are host specific—each Hoplopleura species, including the eight new species described in the present study, parasitizes only a single host species, except Hoplopleura irritans Kuhn and Ludwig, 1967 (Psocodea: Phthiraptera: Hoplopleuridae) and Hoplopleura melomydis Weaver, 2017 (Psocodea: Phthiraptera: Hoplopleuridae), each of which is found on two host species. An updated dichotomous key for identifying Australian Hoplopleura species is included.


2020 ◽  
Vol 68 (1) ◽  
pp. 1
Author(s):  
Nicole F. Clark ◽  
Jen A. McComb ◽  
Andrew W. Taylor-Robinson

In order to study the relationships between mistletoes and their host species, comprehensive collections of both mistletoes and hosts are needed. The effect of sampling effort on the estimation of mistletoe host range was demonstrated in a comparison of an inventory of host mistletoe interactions published by Downey in 1998 and a 2019 inventory presented here, which is based on data from collections in the Australian Virtual Herbarium and information in the literature. New hosts were recorded for 93% of the 90 Australian mistletoes. There were 338 previously known hosts recorded to be parasitised by additional mistletoe species, and 317 new host species that were not previously known as mistletoe hosts (25 being alien species). These were from 78 new host genera and 13 new host families. The total number of host species was 1186 within 327 genera from 92 host families. A total of 63% of all Australian mistletoes parasitise species of either Eucalyptus or Acacia or both these genera. The large rise in host species recorded in less than two decades between inventories suggests that current knowledge of hosts is still incomplete, such that further new hosts will be discovered in future. Some mistletoe species show a strong preference to one host family or genus but due to insufficient collecting it is premature to conclude that any of the three species known from a single host are host specific.


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