Parasite evolutionary events inferred from host phylogeny: the case of Labeo species (Teleostei, Cyprinidae) and their dactylogyrid parasites (Monogenea, Dactylogyridae)

1991 ◽  
Vol 69 (3) ◽  
pp. 595-603 ◽  
Author(s):  
Jean-François Guégan ◽  
Jean-François Agnèse

Independent phylogenies of West African Labeo (Teleostei, Cyprinidae) and their gill parasites of the genus Dactylogyrus (Monogenea, Dactylogyridae) are proposed. The phylogeny of Labeo is based on allele characters, whereas the phylogeny of the parasites is based on morphometric features. The comparison of host and parasite phylogenies did not correlate completely with predictions made by using Fahrenholz's rule. Parasites encountered on L. coubie and L. senegalensis seem to have evolved in parallel with their host, or by sequential colonizations between these two related hosts. Whatever the host–parasite evolutionary events between L. coubie and L. senegalensis and their specific dactylogyrids, two hypotheses of host switching on L. parvus and L. roseopunctatus are probable, reflecting a close ecological relationship between the various host taxa. Dactylogyrus brevicirrus and D. nathaliae, found on the gills of L. parvus and L. roseopunctatus, respectively, are each the sister-species of a living parasite on L. coubie. The notions of parallel evolution (or coevolution in a broader sense) and host switching with speciation are discussed. Finally, Fahrenholz's rule is analyzed as a forecasting tool that can be used in systematics.

2021 ◽  
pp. 389-416
Author(s):  
Paul Schmid-Hempel

Macroevolutionary patterns concern phylogenies of hosts and their parasites. From those, co-speciation occurs; but host switching is a common evolutionary process and more likely when hosts are close phylogenetically and geographical ranges overlap. Microevolutionary processes refer to allele frequency changes within population. In arms races, traits of hosts and parasites evolve in one direction in response to selection by the other party. With selective sweeps, advantageous alleles rapidly spread in host or parasite population and can become fixed. With antagonistic negative frequency-dependent fluctuations (Red Queen dynamics) genetic polymorphism in populations can be maintained, even through speciation events. A Red Queen co-evolutionary process can favour sexual over asexual reproduction and maintain meiotic recombination despite its other disadvantages (two-fold cost of sex). Local adaptation of host and parasites exist in various combinations; the relative migration rates of the two parties, embedded in a geographical mosaic, are important for this process.


2016 ◽  
Vol 94 (5) ◽  
pp. 353-360 ◽  
Author(s):  
Ulalume Hernández-Arciga ◽  
L. Gerardo Herrera M. ◽  
Juan B. Morales-Malacara

We used C and N stable isotopes of nectarivorous bats and their ectoparasites to determine the extent to which parasites depend on the host individual for food. The difference in stable isotope values between parasites and host tissues (Δ13C and Δ15N) was used as a proxy of host use. First, we tested the hypothesis that movement among individual Mexican long-tongued bats (Choeronycteris mexicana Tschudi, 1844) is more likely to occur in winged flies than in mites as indicated by higher host–parasite isotopic Euclidian distance (ED). Second, we tested the hypothesis that ectoparasite species in two coexisting bat species representing the C3 (Geoffroy’s tailless bat, Anoura geoffroyi Gray, 1838) and the CAM (lesser long-nosed bat, Leptonycteris yerbabuenae Martínez and Villa-R., 1940) food chains were monoxenous as indicated by their isotopic values. We also examined Δ13C and Δ15N of individual parasites in relation to 13C and 15N reference enrichment factors as an indication of host switching. In general, flies in C. mexicana had higher ED and wider ranges of individual Δ13C and Δ15N than mites, suggesting that host switching occurred to a larger extent. Most ectoparasites species collected in both coexisting bats were monoxenous, but one fly species appears to be oligoxenous. Individual Δ13C and Δ15N values varied widely in these parasite species, suggesting movements within species hosts.


Parasitology ◽  
1999 ◽  
Vol 119 (S1) ◽  
pp. S111-S123 ◽  
Author(s):  
J. A. Jackson

SUMMARYEven the most generalist parasites usually occur in only a subset of potential host species, a tendency which reflects overriding environmental constraints on their distributions in nature. The periodic shifting of these limitations represented by host-switches may have been an important process in the evolution of many host-parasite assemblages. To study such events, however, it must first be established where and when they have occurred. Past host-switches within a group of parasites are usually inferred from a comparison of the parasite phylogeny with that of the hosts. Congruence between the phylogenies is often attributed to a history of association by descent with cospeciation, and incongruence to host-switching or extinction in ‘duplicated’ parasite lineages (which diverged without a corresponding branching of the host tree). The inference of host-switching from incongrucnt patterns is discussed. Difficulties arise because incongruence can frequently be explained by different combinations of biologically distinct events whose relative probabilities are uncertain. Also, the models of host parasite relationships implicit in historical reconstructions may often not allow for plausible sources of incongruence other than host-switching or duplication/extinction, or for the possibility that colonization could, in some circumstances, be disguised by ‘false’ congruence.


Parasitology ◽  
2015 ◽  
Vol 143 (3) ◽  
pp. 366-373 ◽  
Author(s):  
MARCELA P. A. ESPINAZE ◽  
ELÉONORE HELLARD ◽  
IVAN G. HORAK ◽  
GRAEME S. CUMMING

SUMMARYTicks and tick-borne pathogens can have considerable impacts on the health of livestock, wildlife and people. Knowledge of tick–host preferences is necessary for both tick and pathogen control. Ticks were historically considered as specialist parasites, but the range of sampled host species has been limited, infestation intensity has not been included in prior analyses, and phylogenetic distances between hosts have not been previously considered. We used a large dataset of 35 604 individual collections and two host-specificity indices to assess the specificity of 61 South African tick species, as well as distinctions between adult and juvenile ticks, for 95 mammalian hosts. When accounting for host phylogeny, most adult and juvenile ticks behaved as generalists, with juveniles being significantly more generalist than adults. When we included the intensity of tick infestation, ticks exhibited a wider diversity of specificity in all life stages. Our results show that ticks of mammals in South Africa tend to behave largely as generalists and that adult ticks are more host-specific. More generally, our analysis shows that the incorporation of life-stage differences, infestation intensity and phylogenetic distances between hosts, as well as the use of more than one specificity index, can all contribute to a deeper understanding of host–parasite interactions.


Parasitology ◽  
2012 ◽  
Vol 139 (13) ◽  
pp. 1749-1756 ◽  
Author(s):  
LEONARDO DOMINICI CRUZ ◽  
FERNANDA RODRIGUES FERNANDES ◽  
ARÍCIO XAVIER LINHARES

SUMMARYPhylogenetic and geographical overlaps in host distributions influence the compositional similarity of ectoparasite fauna in a host–parasite system. In these systems, hosts that are more closely related (phylogenetically) are expected to share more parasitic species than more distantly related hosts. Similarly, hosts sharing a larger geographical distribution overlap are expected to have similar ectoparasites. This study investigated the influence of phylogeny (divergence time) and geographical overlap of some neotropical sigmodontine rodent species on the similarities among their ectoparasite fauna (Mesostigmata and Siphonaptera), using a partial Mantel test. Divergence time was the only significant factor that influenced the similarity among the ectoparasites, when mites and fleas were analysed together. Host species that had diverged more recently displayed ectoparasite fauna that were similar. The similarities of the flea species showed similar results in both separate and joint analyses, but neither phylogenetic nor geographical overlap influenced the similarity in mite species. Fleas were shown to be more host-specific than were mesostigmate mites, probably because of the increased influence of host phylogeny.


Parasitology ◽  
2012 ◽  
Vol 139 (10) ◽  
pp. 1346-1360 ◽  
Author(s):  
KIRILL V. GALAKTIONOV ◽  
ISABEL BLASCO-COSTA ◽  
PETER D. OLSON

SUMMARYThe ‘pygmaeus’ microphallids (MPG) are a closely related group of 6 digenean (Platyhelminthes: Trematoda) Microphallus species that share a derived 2-host life cycle in which metacercariae develop inside daughter sporocysts in the intermediate host (intertidal and subtidal gastropods, mostly of the genus Littorina) and are infective to marine birds (ducks, gulls and waders). Here we investigate MPG transmission patterns in coastal ecosystems and their diversification with respect to historical events, host switching and host-parasite co-evolution. Species phylogenies and phylogeographical reconstructions are estimated on the basis of 28S, ITS1 and ITS2 rDNA data and we use a combination of analyses to test the robustness and stability of the results, and the likelihood of alternative biogeographical scenarios. Results demonstrate that speciation within the MPG was not associated with co-speciation with either the first intermediate or final hosts, but rather by host-switching events coincident with glacial cycles in the Northern Hemisphere during the late Pliocene/Pleistocene. These resulted in the expansion of Pacific biota into the Arctic-North Atlantic and periodic isolation of Atlantic and Pacific populations. Thus we hypothesize that contemporary species of MPG and their host associations resulted from fragmentation of populations in regional refugia during stadials, and their subsequent range expansion from refugial centres during interstadials.


2020 ◽  
Author(s):  
Maren Preuss ◽  
Giuseppe Zuccarello

2018 International Phycological Society There are over 120 species of red algal parasites (Florideophyceae) but they are often overlooked due to their small size and patchy distribution. Red algal parasites have mostly been described as independent genera but recent phylogenetic studies have shown that parasites are related to free-living relatives, often their hosts, and have been named in these genera to maintain monophyly. We investigated the morphology, distribution and phylogeny, using diverse molecular markers (mitochondrial, nuclear, plastid), of three new red algal parasites in New Zealand. We describe the parasites using morphological and anatomical observations and estimate their distribution by surveying herbarium vouchers. Analyses of reproductive structures and molecular phylogenies indicate that the closest relative of the parasite Phycodrys novae-zelandiaephila sp. nov. is its host, Phycodrys novae-zelandiae. Based on nuclear and mitochondrial markers, the closest relative of the parasite Cladhymenia oblongifoliaphila sp. nov. is its host Cladhymenia oblongifolia but plastid markers group it with Cladhymenia lyallii, suggesting that this species was a past host and the source of parasite plastids. The parasite Judithia parasitica sp. nov. groups with Judithia delicatissima but infects Blastophyllis spp., suggesting that this parasite evolved as a free-living or parasitic Judithia species, and host switching may have occurred. This study adds to our knowledge of New Zealand red algal parasites and highlights contrasting patterns of host–parasite relationships.


2020 ◽  
Author(s):  
Philip M. Riekenberg ◽  
Marine J. Briand ◽  
Thibaud Moléana ◽  
Pierre Sasal ◽  
Marcel van der Meer ◽  
...  

AbstractStable isotopes of carbon and nitrogen characterize trophic relationships in predator-prey relationships, with clear differences between consumer and diet (discrimination factor, Δ13C, Δ15N). However, parasite-host isotopic relationships remain unclear, with Δ13C and Δ15N remaining incompletely characterized, especially for helminths. In this study, we used stable isotopes to determine discrimination factors for 13 parasite-host pairings of helminths in coral reef fish. Δ15N differences grouped according to phylogeny and attachment site on the hosts: Δ15N was positive for trematodes and nematodes from the digestive tract and varied for cestodes and nematodes from the general cavity. Δ13C showed more complex patterns with no effect of phylogeny or attachment site. A negative relationship was observed between Δ15N and host δ15N value among different host-parasite pairings as well as within 7 out of the 13 parings, indicating that host metabolic processing affects host-parasite discrimination values. In contrast, no relationships were observed for Δ13C. Our results indicate that host phylogeny, attachment site and host stable isotope value drive Δ15N of helminths in coral reef fish while Δ13C is more idiosyncratic. These results call for use of taxon- or species-specific and scaled framework for bulk stable isotopes in the trophic ecology of parasites.


2021 ◽  
Vol 376 (1837) ◽  
pp. 20200351 ◽  
Author(s):  
Maxwell J. Farrell ◽  
Andrew W. Park ◽  
Clayton E. Cressler ◽  
Tad Dallas ◽  
Shan Huang ◽  
...  

A growing body of research is focused on the extinction of parasite species in response to host endangerment and declines. Beyond the loss of parasite species richness, host extinction can impact apparent parasite host specificity, as measured by host richness or the phylogenetic distances among hosts. Such impacts on the distribution of parasites across the host phylogeny can have knock-on effects that may reshape the adaptation of both hosts and parasites, ultimately shifting the evolutionary landscape underlying the potential for emergence and the evolution of virulence across hosts. Here, we examine how the reshaping of host phylogenies through extinction may impact the host specificity of parasites, and offer examples from historical extinctions, present-day endangerment, and future projections of biodiversity loss. We suggest that an improved understanding of the impact of host extinction on contemporary host–parasite interactions may shed light on core aspects of disease ecology, including comparative studies of host specificity, virulence evolution in multi-host parasite systems, and future trajectories for host and parasite biodiversity. This article is part of the theme issue ‘Infectious disease macroecology: parasite diversity and dynamics across the globe’.


2020 ◽  
Vol 60 (1) ◽  
pp. 57-69 ◽  
Author(s):  
Talisin T Hammond ◽  
Chelsea A Ortiz-Jimenez ◽  
Jennifer E Smith

Synopsis Anthropogenic change has well-documented impacts on stress physiology and behavior across diverse taxonomic groups. Within individual organisms, physiological and behavioral traits often covary at proximate and ultimate timescales. In the context of global change, this means that impacts on physiology can have downstream impacts on behavior, and vice versa. Because all organisms interact with members of their own species and other species within their communities, the effects of humans on one organism can impose indirect effects on one or more other organisms, resulting in cascading effects across interaction networks. Human-induced changes in the stress physiology of one species and the downstream impacts on behavior can therefore interact with the physiological and behavioral responses of other organisms to alter emergent ecological phenomena. Here, we highlight three scenarios in which the stress physiology and behavior of individuals on different sides of an ecological relationship are interactively impacted by anthropogenic change. We discuss host–parasite/pathogen dynamics, predator–prey relationships, and beneficial partnerships (mutualisms and cooperation) in this framework, considering cases in which the effect of stressors on each type of network may be attenuated or enhanced by interactive changes in behavior and physiology. These examples shed light on the ways that stressors imposed at the level of one individual can impact ecological relationships to trigger downstream consequences for behavioral and ecological dynamics. Ultimately, changes in stress physiology on one or both sides of an ecological interaction can mediate higher-level population and community changes due in part to their cascading impacts on behavior. This framework may prove useful for anticipating and potentially mitigating previously underappreciated ecological responses to anthropogenic perturbations in a rapidly changing world.


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