seasonal and demographic factors influencing gastrointestinal parasitism in ungulates of etosha national dynamics can be strongly affected by seasonality and age-related host immune responses. we investigated how observed variation in the prevalence and intensity of parasite egg or oocyst shedding in four co-occurring ungulate species may reflect underlying seasonal variation in transmission and host immunity. this study was conducted july 2005-october 2006 in etosha national park, namibia, using indices of parasitism recorded from 1,022 fecal samples collected from plains zebra (equu ...201020966262
genetic diversity of piroplasms in plains zebra (equus quagga burchellii) and cape mountain zebra (equus zebra zebra) in south africa.seventy edta blood samples collected from plains zebra (equus quagga burchellii) and cape mountain zebra (equus zebra zebra) were screened for the presence of piroplasm parasite dna using quantitative t. equi-specific and b. caballi-specific taqman real-time pcr (qpcr) tests. t. equi parasite dna was detected in 60 samples, 19 of which were also positive for b. caballi. approximately 1480bp of the piroplasm 18s rrna gene was amplified and sequenced from 17 samples, while the v4 hypervariable reg ...201020833476
phylogeography and systematics of zebra mussels and related species.the genus dreissena includes two widespread and aggressive aquatic invaders, the zebra mussel, dreissena polymorpha, and the quagga mussel, dreissena bugensis. this genus evolved in the ponto-caspian sea basin, characterized by dynamic instability over multiple timescales and a unique evolutionary environment that may predispose to invasiveness. the objectives of this study were to gain insights into the demographic history of dreissena species in their endemic range, to reconstruct intraspecifi ...200616599965
invasion genetics of a freshwater mussel (dreissena rostriformis bugensis) in eastern europe: high gene flow and multiple recent years, the quagga mussel, dreissena rostriformis bugensis, native to the dnieper and bug limans of the northern black sea, has been dispersed by human activities across the basin, throughout much of the volga river system, and to the laurentian great lakes. we used six published microsatellite markers to survey populations throughout its native and introduced range to identify relationships among potential source populations and introduced ones. mussels from 12 sites in eurasia, includ ...200515931246
migratory herds of wildebeests and zebras indirectly affect calf survival of long-distance migratory systems, local fluctuations in the predator-prey ratio can exhibit extreme variability within a single year depending upon the seasonal location of migratory species. such systems offer an opportunity to empirically investigate cyclic population density effects on short-term food web interactions by taking advantage of the large seasonal shifts in migratory prey biomass.we utilized a large-mammal predator-prey savanna food web to evaluate support for hypotheses relatin ...201628031792
phylogenetic analysis of the microbial populations in the wild herbivore gastrointestinal tract: insights into an unexplored present, there is little information on the phylogenetic diversity of microbial species that inhabit the gastrointestinal tracts of wildlife. to increase understanding in this area, we initiated a characterization of the bacterial diversity in the digestive tracts of three wild african ruminant species namely eland (taurotragus oryx), thompson's gazelle (gazella rufifrons) and grant's gazelle (gazella granti), together with a domesticated ruminant species, zebu cattle (bos indicus), and a non ...200314641599
putative clinical piroplasmosis in a burchell's zebra (equus quagga burchelli).a 10-year-old tame zebra gelding was presented after suffering from lethargy, nervousness, reported anaemia and icterus as well as a decreased appetite. these symptoms were seen over some months, with changing severity. the animal was immobilised, treated, and blood specimens were submitted for haematology and biochemistry. this report describes molecular characterisation of theileria equi recovered from this animal, as well as the clinical findings, treatment and historical relevance of piropla ...200920458869
chromosomal distribution of the telomere sequence (ttaggg)(n) in the equidae.telomeres are a class of repetitive dna sequences that are located at chromosome termini and that act to stabilize the chromosome ends. the rapid karyotypic evolution of the genus equus has given rise to ten taxa, all with different diploid chromosome numbers. using fluorescence in situ hybridization (fish) we localized the mammalian telomere sequence, (ttaggg)(n), to the chromosomes of nine equid taxa. ttaggg signal was located at chromosome termini in all species, however additional signal was ...200111474195
homologous fission event(s) implicated for chromosomal polymorphisms among five species in the genus equus.the genus equus is unusual in that five of the ten extant species have documented centric fission (robertsonian translocation) polymorphisms within their populations, namely e. hemionus onager, e. hemionus kulan, e. kiang, e. africanus somaliensis, and e. quagga burchelli. here we report evidence that the polymorphism involves the same homologous chromosome segments in each species, and that these chromosome segments have homology to human chromosome 4 (hsa4). bacterial artificial chromosome clo ...200314970706
mitochondrial dna of the extinct quagga: relatedness and extent of postmortem change.sequences are reported for portions of two mitochondrial genes from a domestic horse and a plains zebra and compared to those published for a quagga and a mountain zebra. the extinct quagga and plains zebra sequences are identical at all silent sites, whereas the horse sequence differs from both of them by 11 silent substitutions. postmortem changes in quagga dna may account for the two coding substitutions between the quagga and plains zebra sequences. the hypothesis that the closest relative o ...19872822938
immunological systematics of the extinct quagga (equidae).it has been debated whether the extinct quagga was a distinct fourth species of african zebra or whether it was merely the southern variant of the plains zebra (equus burchelli). using a radioimmunoassay (ria) technique, we have shown that proteins remaining in quagga skins from museums are much more similar to serum proteins of the plains zebra than to those of the other two extant zebras.19854043335
a serologic and polymerase chain reaction survey of equine herpesvirus in burchell's zebras (equus quagga), hartmann's mountain zebras (equus zebra hartmannae), and thomson's gazelles (eudorcas thomsonii) in a mixed species savannah exhibit.reports of equine herpesvirus (ehv) 1 and ehv-9 causing clinical disease in a wide range of species have been well documented in the literature. it is thought that zebras are the natural hosts of ehv-9 both in the wild and in captive collections. concerns about potential interspecies transmission of ehv-1 and ehv-9 in a mixed species savannah exhibit prompted serologic and polymerase chain reaction surveys. eighteen burchell's zebras ( equus quagga ), 11 hartmann's mountain zebras ( equus zebra ...201628080902
fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites.parasites can shape the foraging behaviour of their hosts through cues indicating risk of infection. when cues for risk co-occur with desired traits such as forage quality, individuals face a trade-off between nutrient acquisition and parasite exposure. we evaluated how this trade-off may influence disease transmission in a 3-year experimental study of anthrax in a guild of mammalian herbivores in etosha national park, namibia. at plains zebra (equus quagga) carcass sites we assessed (i) carcass ...201425274365
gastrointestinal helminths may affect host susceptibility to anthrax through seasonal immune trade-offs.most vertebrates experience coinfections, and many pathogen-pathogen interactions occur indirectly through the host immune system. these interactions are particularly strong in mixed micro-macroparasite infections because of immunomodulatory effects of helminth parasites. while these trade-offs have been examined extensively in laboratory animals, few studies have examined them in natural systems. additionally, many wildlife pathogens fluctuate seasonally, at least partly due to seasonal host im ...201425388877
variation in faecal water content may confound estimates of gastro-intestinal parasite intensity in wild african herbivores.estimates of parasite intensity within host populations are essential for many studies of host-parasite relationships. here we evaluated the seasonal, age- and sex-related variability in faecal water content for two wild ungulate species, springbok (antidorcas marsupialis) and plains zebra (equus quagga). we then assessed whether or not faecal water content biased conclusions regarding differences in strongyle infection rates by season, age or sex. there was evidence of significant variation in ...201019627626
shedding of clostridium difficile pcr ribotype 078 by zoo animals, and report of an unstable metronidazole-resistant isolate from a zebra foal (equus quagga burchellii).clostridium difficile is an emerging and potentially zoonotic pathogen, but its prevalence in most animal species, including exhibition animals, is currently unknown. in this study we assessed the prevalence of faecal shedding of c. difficile by zoo animals, and determined the ribotype, toxin profile and antimicrobial susceptibility of recovered isolates. a total of 200 samples from 40 animal species (36.5% of which came from plains zebra, equus quagga burchellii) were analysed. c. difficile was ...201424467928
the quagga mussel crisis at lake mead national recreation area, nevada (u.s.a.).parks are cornerstones of conservation; and non-native invasive species drive extensive changes to biological diversity in parks. knowing this, national park staff at lake mead national recreation area in the southwestern united states had a program in place for early detection of the non-native, invasive quagga mussel (dreissena rostriformis bugensis). upon finding the mussel in january 2007, managers moved quickly to access funding and the best available science to implement a response. manage ...201020337691
high variation and very low differentiation in wide ranging plains zebra (equus quagga): insights from mtdna and microsatellites.patterns of genetic differentiation in the plains zebra (equus quagga) were analysed using mitochondrial dna control region variation and seven microsatellites. the six morphologically defined subspecies of plains zebra lacked the population genetic structure indicative of distinct evolutionary units. both marker sets showed high levels of genetic variation and very low levels of differentiation. there was no geographical structuring of mitochondrial dna haplotypes in the phylogenetic tree, and ...200818466230
a rapid loss of stripes: the evolutionary history of the extinct quagga.twenty years ago, the field of ancient dna was launched with the publication of two short mitochondrial (mt) dna sequences from a single quagga (equus quagga) museum skin, an extinct south african equid (higuchi et al. 1984 nature312, 282-284). this was the first extinct species from which genetic information was retrieved. the dna sequences of the quagga showed that it was more closely related to zebras than to horses. however, quagga evolutionary history is far from clear. we have isolated dna ...200517148190
ancient dna is thirteen years old.the first successful recovery of ancient dna, from quagga and human mummies inspired significant enough interest to open an entire field of research. efforts from many research groups, often in a hunt for the oldest sequences, showed that ancient dna was a poor substrate for the enzymes used in molecular biology; it is present in tiny amounts, hard to purify, and frequently damaged. these obstacles have been partially overcome by the use of drastic laboratory precautions and by the introduction ...19979306399
mass spectral analysis of domestic and wild equine apoa-i and a-ii: detection of unique dimeric forms of pigs, humans, chimpanzees and probably other great apes, a cysteine at residue 6 enables apolipoprotein a-ii to form a homodimer. however, the apoa-iis of other primates, lacking a cysteine residue, are monomeric. we have already reported that horse apoa-iis form homodimers due also to a cysteine at residue 6. in this study, we wanted to determine whether other equine apoa-iis might be monomeric. the high density lipoproteins were ultracentrifugally isolated from the plasmas of a horse (equus ...200516230041
ecotoxicological impact of zequanox®, a novel biocide, on selected non-target irish aquatic species.effective, species-specific zebra mussel control is needed urgently for ireland׳s freshwater bodies, which became infested with non-native zebra mussels in the 1990s. zequanox®, a newly commercialized product for zebra and quagga mussel control, is composed of dead pseudomonas fluorescens cl 145a cells. this paper describes ecotoxicology tests on three representative native irish freshwater species: anodonta (duck mussel), chironomus plumosus (non-biting midge), and austropotamobius pallipes (wh ...201424927392
pattern of faecal 20-oxopregnane and oestrogen concentrations during pregnancy in wild plains zebra mares.regulative endocrine mechanisms influence the reproductive behaviour and success of mammals, but they have been studied predominantly in domestic and captive animals. the study aims at describing the pattern of faecal 20-oxopregnane and oestrogen concentrations during pregnancy in wild plains zebra equus quagga chapmani. data were collected during wet and dry seasons 2007-2009. enzyme immunoassays were used to determine 20-oxopregnane and oestrogen concentrations in faecal samples (n=74) collect ...201121463629
pseudomonas fluorescens strain cl145a - a biopesticide for the control of zebra and quagga mussels (bivalvia: dreissenidae).zebra mussels (dreissena polymorpha) and quagga mussels (dreissena rostriformis bugensis) are the "poster children" of high-impact aquatic invasive species. in an effort to develop an effective and environmentally acceptable method to control their fouling of raw-water conduits, we have investigated the potential use of bacteria and their natural metabolic products as selective biological control agents. an outcome of this effort was the discovery of pseudomonas fluorescens strain cl145a - an en ...201323295683
validated methodology for quantifying infestation levels of dreissenid mussels in environmental dna (edna) samples.the zebra mussel (dreissena polymorpha pallas, 1771) and the quagga mussel (d. rostriformis deshayes, 1838) are successful invasive bivalves with substantial ecological and economic impacts in freshwater systems once they become established. since their eradication is extremely difficult, their detection at an early stage is crucial to prevent spread. in this study, we optimized and validated a qpcr detection method based on the histone h2b gene to quantify combined infestation levels of zebra a ...201627966602
a comparative study of byssogenesis on zebra and quagga mussels: the effects of water temperature, salinity and light-dark cycle.the quagga mussel (dreissena rostriformis bugensis) and zebra mussel (dreissena polymorpha) are invasive freshwater bivalves in europe and north america. the distribution range of both dreissena species is still expanding and both species cause major biofouling and ecological effects, in particular when they invade new areas. in order to assess the effect of temperature, salinity and light on the initial byssogenesis of both species, 24 h re-attachment experiments in standing water were conducte ...201222296220
comparison of bioaccumulation and biomarker responses in dreissena polymorpha and d. bugensis after exposure to resuspended sediments.the zebra mussel dreissena polymorpha is widely used as sentinel organism for the assessment of environmental contamination in freshwater environments. however, in the river rhine (germany), the d. polymorpha population is declining, whereas the closely related quagga mussel d. bugensis is found in high numbers at some sites. in the present laboratory study, d. polymorpha and d. bugensis were exposed to resuspended native sediments for ≤2 weeks. wet sediments (<63 μm, 100 mg l(-1) dry weight) we ...201222231661
early detection monitoring for larval dreissenid mussels: how much plankton sampling is enough?the development of quagga and zebra mussel (dreissenids) monitoring programs in the pacific northwest provides a unique opportunity to evaluate a regional invasive species detection effort early in its development. recent studies suggest that the ecological and economic costs of a dreissenid infestation in the pacific northwest of the usa would be significant. consequently, efforts are underway to monitor for the presence of dreissenids. however, assessments of whether these efforts provide for ...201728168527
modeling metal bioaccumulation in the invasive mussels dreissena polymorpha and dreissena rostriformis bugensis in the rivers rhine and meuse.the metal-specific covalent index and the species-specific size-based filtration rate were integrated into a biokinetic model estimating metal bioaccumulation in mussels from the dissolved phase and phytoplankton. the model was validated for zebra (dreissena polymorpha) and quagga (dreissena rostriformis bugensis) mussels in the rivers rhine and meuse, the netherlands. the model performed well in predicting tissue concentrations in different-sized zebra mussels from various sampling sites for (5 ...201121953991
do invasive mussels restrict offshore phosphorus transport in lake huron?dreissenid mussels were first documented in the laurentian great lakes in the late 1980s. zebra mussels (dreissena polymorpha) spread quickly into shallow, hard-substrate areas; quagga mussels (dreissena rostriformis bugensis) spread more slowly and are currently colonizing deep, offshore areas. these mussels occur at high densities, filter large water volumes while feeding on suspended materials, and deposit particulate waste on the lake bottom. this filtering activity has been hypothesized to ...201121812427
estimation and management of genetic diversity in small populations of plains zebra (equus quagga) in kwazulu-natal, south africa.plains zebras (equus quagga antiquorum) occur in few large, but many small, isolated populations in kwazulu-natal. problems identified in small populations include reduced striping patterns on hind quarters, smaller size, elevated mortality rates and high number of still-births. inbreeding may be implicated. population viability analysis (pva) was conducted with a computer model (vortex), and dna and allozyme analyses were conducted to test the findings of the model. using standard methods, dna ...200111336807
effects of shell morphology on mechanics of zebra and quagga mussel locomotion.although zebra mussels (dreissena polymorpha) initially colonized shallow habitats within the north american great lakes, quagga mussels (dreissena bugensis) are becoming dominant in both shallow- and deep-water habitats. shell morphology differs among zebra, shallow quagga and deep quagga mussels but functional consequences of such differences are unknown. we examined effects of shell morphology on locomotion for the three morphotypes on hard (typical of shallow habitats) and soft (characterist ...201121653816
microsatellite loci for dreissenid mussels (mollusca: bivalvia: dreissenidae) and relatives: markers for assessing exotic and native populations.we developed and tested 14 new polymorphic microsatellite loci for dreissenid mussels, including the two species that have invaded many freshwater habitats in eurasia and north america, where they cause serious industrial fouling damage and ecological alterations. these new loci will aid our understanding of their genetic patterns in invasive populations as well as throughout their native ponto-caspian distributions. eight new loci for the zebra mussel dreissena polymorpha polymorpha and six for ...201121457480
acute upper thermal limits of three aquatic invasive invertebrates: hot water treatment to prevent upstream transport of invasive species.transport of aquatic invasive species (ais) by boats traveling up rivers and streams is an important mechanism of secondary spread of ais into watersheds. because physical barriers to ais movement also prevent navigation, alternate methods for preventing spread are necessary while allowing upstream navigation. one promising approach is to lift boats over physical barriers and then use hot water immersion to kill ais attached to the hull, motor, or fishing gear. however, few data have been publis ...201120936280
developmental plasticity of shell morphology of quagga mussels from shallow and deep-water habitats of the great lakes.the invasive zebra mussel (dreissena polymorpha) has quickly colonized shallow-water habitats in the north american great lakes since the 1980s but the quagga mussel (dreissena bugensis) is becoming dominant in both shallow and deep-water habitats. while quagga mussel shell morphology differs between shallow and deep habitats, functional causes and consequences of such difference are unknown. we examined whether quagga mussel shell morphology could be induced by three environmental variables thr ...201020639421
a dominance shift from the zebra mussel to the invasive quagga mussel may alter the trophic transfer of metals.bioinvasions are a major cause of biodiversity and ecosystem changes. the rapid range expansion of the invasive quagga mussel (dreissena rostriformis bugensis) causing a dominance shift from zebra mussels (dreissena polymorpha) to quagga mussels, may alter the risk of secondary poisoning to predators. mussel samples were collected from various water bodies in the netherlands, divided into size classes, and analysed for metal concentrations. concentrations of nickel and copper in quagga mussels w ...201525910461
development of a molecular diagnostic system to discriminate dreissena polymorpha (zebra mussel) and dreissena bugensis (quagga mussel).a 3-primer pcr system was developed to discriminate invasive zebra (dreissena polymorpha) and quagga (dreissena bugensis) mussel. the system is based on: 1) universal primers that amplifies a region of the nuclear 28s rdna gene from both species and 2) a species-specific primer complementary to either zebra or quagga mussel. the species-specific primers bind to sequences between the binding sites for the universal primers resulting in the amplification of two products from the target species and ...201021565008
zebra mussels anchor byssal threads faster and tighter than quagga mussels in flow.while the invasive zebra mussel dreissena polymorpha has rapidly spread throughout the great lakes and inland waterways, it is being displaced by the quagga mussel dreissena bugensis in shallow water habitats. however, zebra mussels remain dominant in areas with higher water velocity. we hypothesized that the persistence of zebra over quagga mussels in habitats with higher water velocity might result from greater rate and strength of byssal thread attachment. we examined whether zebra mussels re ...200919525429
frequent and seasonally variable sublethal anthrax infections are accompanied by short-lived immunity in an endemic system.few studies have examined host-pathogen interactions in wildlife from an immunological perspective, particularly in the context of seasonal and longitudinal dynamics. in addition, though most ecological immunology studies employ serological antibody assays, endpoint titre determination is usually based on subjective criteria and needs to be made more objective. despite the fact that anthrax is an ancient and emerging zoonotic infectious disease found world-wide, its natural ecology is not well u ...201424499424
broad shifts in the resource use of a commercially harvested fish following the invasion of dreissenid mussels.dreissenid mussels -ndash-including the zebra (dreissena polymorpha) and quagga (dreissena rostiformus bugensis) mussel-ndash- are invasive species known for their capacity to act as ecosystem engineers. they have caused significant changes in the many freshwater systems they have invaded by increasing water clarity, reducing primary productivity, and altering zooplankton and benthic invertebrate assemblages. what is less clear is how their ecosystem engineering effects manifest up the food web ...201728369860
dna sequences from the quagga, an extinct member of the horse determine whether dna survives and can be recovered from the remains of extinct creatures, we have examined dried muscle from a museum specimen of the quagga, a zebra-like species (equus quagga) that became extinct in 1883 (ref. 1). we report that dna was extracted from this tissue in amounts approaching 1% of that expected from fresh muscle, and that the dna was of relatively low molecular weight. among the many clones obtained from the quagga dna, two containing pieces of mitochondrial dna ...19846504142
competitive replacement of invasive congeners may relax impact on native species: interactions among zebra, quagga, and native unionid mussels.determining when and where the ecological impacts of invasive species will be most detrimental and whether the effects of multiple invaders will be superadditive, or subadditive, is critical for developing global management priorities to protect native species in advance of future invasions. over the past century, the decline of freshwater bivalves of the family unionidae has been greatly accelerated by the invasion of dreissena. the purpose of this study was to evaluate the current infestation ...201425490103
using dna barcoding to differentiate invasive dreissena species (mollusca, bivalvia).the zebra mussel (dreissena polymorpha) and the quagga mussel (dreissena rostriformis bugensis) are considered as the most competitive invaders in freshwaters of europe and north america. although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus dreissena does not always allow a clear identification. therefore, the need to find an accurate identification method is essential. dna barcoding has been proven to be an adequate procedure to discriminate spe ...201324453560
diagnostic genetic markers and evolutionary relationships among invasive dreissenoid and corbiculoid bivalves in north america: phylogenetic signal from mitochondrial 16s rdna.diagnostic genetic markers from 486 aligned nucleotide sequences of mitochondrial 16s ribosomal dna were developed for the four closely related species of dreissenoid and corbiculoid bivalves that have invaded north america; the zebra mussel dreissena polymorpha, the quagga mussel d. bugensis, and the dark false mussel mytilopsis leucophaeata of the superfamily dreissenoidea, and the asian clam corbicula fluminea of the sister superfamily corbiculoidea. evolutionary relationships were examined a ...199910508537
a diagnostic molecular marker for zebra mussels (dreissena polymorpha) and potentially co-occurring bivalves: mitochondrial coi.we report diagnostic differences in the nucleotide sequences of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit i gene (coi) from the zebra mussel (dreissena polymorpha) and potentially co-occurring bivalves: the quagga mussel (dreissena bugensis); the asiatic clam (corbicula fluminea), the dark false mussel (mytilopsis leucophaeata), and the wedge clam (rangia cuneata). the coi sequence of the deep-water "profunda" phenotype of the quagga mussel was nearly identical to that ...19968869514
will the displacement of zebra mussels by quagga mussels increase water clarity in shallow lakes during summer? results from a mesocosm experiment.zebra mussels (dreissena polymorpha) are known to increase water clarity and affect ecosystem processes in invaded lakes. during the last decade, the conspecific quagga mussels (d. rostriformis bugensis) have displaced zebra mussels in many ecosystems including shallow lakes such as oneida lake, new york. in this study, an eight-week mesocosm experiment was conducted to test the hypothesis that the displacement of zebra mussels by quagga mussels leads to further decreases in phytoplankton and in ...201628005940
the prevalence and transmission to exotic equids (equus quagga antiquorum, equus przewalskii, equus africanus) of intestinal nematodes in contaminated pasture in two wild animal parks.wild equids maintained in large enclosures may suffer from helminth diseases because common hygiene practices have only limited effects on parasite populations. weekly monitoring of helminth prevalences and pasture infestation was performed for 1 yr in several extensive maintenance systems of two wildlife parks with similar climates to determine when veterinary intervention to control parasites would be useful. we also sought evidence of natural immunogenic reactions among herds of chapman zebra ...200112790423
ecosystem transformations of the laurentian great lake michigan by nonindigenous biological invaders.lake michigan, a 58,000-km(2) freshwater inland sea, is large enough to have persistent basin-scale circulation yet small enough to enable development of approximately balanced budgets for water, energy, and elements including carbon and silicon. introduction of nonindigenous species-whether through invasion, intentional stocking, or accidental transplantation-has transformed the lake's ecosystem function and habitat structure. of the 79 nonindigenous species known to have established reproducti ...201322809179
diet quality in a wild grazer declines under the threat of an ambush predator.predators influence prey populations not only through predation itself, but also indirectly through prompting changes in prey behaviour. the behavioural adjustments of prey to predation risk may carry nutritional costs, but this has seldom been studied in the wild in large mammals. here, we studied the effects of an ambush predator, the african lion (panthera leo), on the diet quality of plains zebras (equus quagga) in hwange national park, zimbabwe. we combined information on movements of both ...201424789903
placentation in the plains zebra (equus quagga).the placenta and fetal gonads of 12 pregnant plains zebra (equus quagga), estimated to be between 81 and 239 days of gestation, were examined. the diffuse, microcotyledonary zebra placenta appeared, developmentally, to be 3-4 weeks behind its counterpart in horse pregnancy and this, together with the presence of small and long-lived endometrial cups, low levels of zebra chorionic gonadotrophin in maternal serum and few accessory corpora lutea in the maternal ovaries during the first half of gest ...201728356184
between-gender differences in vigilance do not necessarily lead to differences in foraging-vigilance tradeoffs.when prey are time limited in their access to food, any trade-off involving time should ultimately affect their intake rate. in many herbivores, males and females experience different ecological pressures affecting their survival and reproduction because of differences in morphology, physiology and energy/nutrient requirements. if males and females have different vigilance strategies that affect their intake rates differently, they will suffer different foraging costs. this is particularly relev ...201627017605
population genetic diversity and hybrid detection in captive zebras.zebras are members of the horse family. there are three species of zebras: the plains zebra equus quagga, the grevy's zebra e. grevyi and the mountain zebra e. zebra. the grevy's zebra and the mountain zebra are endangered, and hybridization between the grevy's zebra and the plains zebra has been documented, leading to a requirement for conservation genetic management within and between the species. we characterized 28 microsatellite markers in grevy's zebra and assessed cross-amplification in p ...201526294133
unraveling the effects of selection and demography on immune gene variation in free-ranging plains zebra (equus quagga) populations.demography, migration and natural selection are predominant processes affecting the distribution of genetic variation among natural populations. many studies use neutral genetic markers to make inferences about population history. however, the investigation of functional coding loci, which directly reflect fitness, is critical to our understanding of species' ecology and evolution. immune genes, such as those of the major histocompatibility complex (mhc), play an important role in pathogen recog ...201223251409
adaptive molecular evolution of the major histocompatibility complex genes, dra and dqa, in the genus equus.abstract: background: major histocompatibility complex (mhc) genes are central to vertebrate immune response and are believed to be under balancing selection by pathogens. this hypothesis has been supported by observations of extreme genetic diversity, elevated nonsynonymous to synonymous base pair substitution rates and trans-species polymorphism at these loci. in equids, the organization and variability of this gene family has been described, however the full extent of diversity and selection ...201121592397
speciation with gene flow in equids despite extensive chromosomal plasticity.horses, asses, and zebras belong to a single genus, equus, which emerged 4.0-4.5 mya. although the equine fossil record represents a textbook example of evolution, the succession of events that gave rise to the diversity of species existing today remains unclear. here we present six genomes from each living species of asses and zebras. this completes the set of genomes available for all extant species in the genus, which was hitherto represented only by the horse and the domestic donkey. in addi ...201425453089
evolutionary constraints on equid domestication: comparison of flight initiation distances of wild horses (equus caballus ferus) and plains zebras (equus quagga).habituation to humans was an essential component of horse (equus caballus ferus) domestication, with the nondomestication of zebras (equus quagga) possibly reflecting an adaptive constraint on habituation. we present the human hunting hypothesis, arguing that ancestral humans hunted african animals, including zebras, long enough to promote a persistent wariness of humans, whereas a briefer period of hunting horses in central asia influenced by glacial cycles was unlikely to produce an equally pe ...201526348970
phylogenetic relationships among perissodactyla: secretoglobin 1a1 gene duplication and triplication in the equidae family.secretoglobin family 1a member 1 (scgb 1a1) is a small anti-inflammatory and immunomodulatory protein that is abundantly secreted in airway surface fluids. we recently reported the existence of three distinct scgb1a1 genes in the domestic horse genome as opposed to the single gene copy consensus present in other mammals. the origin of scgb1a1 gene triplication and the evolutionary relationship of the three genes amongst equidae family members are unknown. for this study, scgb1a1 genomic data wer ...201323988306
chaetogaster limnaei (annelida: oligochaeta) as a parasite of the zebra mussel dreissena polymorpha, and the quagga mussel dreissena bugensis (mollusca: bivalvia).dreissenid mussels, dreissena polymorpha and d. bugensis, were found to be infected by the naidid oligochaete chaetogaster limnaei at four sites in the st. lawrence river. this is the first report of this species infecting dreissenids anywhere in the world. most worms inhabited the mantle cavity, where they caused erosion of the mantle and gill epithelia as determined by histopathological examination. others penetrated various tissues; one had invaded the ovary and was feeding on oocytes and ova ...19968825436
the byssus of the zebra mussel, dreissena polymorpha. ii: structure and polymorphism of byssal polyphenolic protein families.the byssus of the zebra mussel dreissena polymorpha is the key element of its adhesive strategy. it consists of a bundle of threads tipped by adhesive plaques and attached to the mussel at the base of its byssal-synthesizing organ, the foot. two polyphenolic protein precursors of the byssus have been purified from the foot. these precursors, dpfp-1 and dpfp-2 (dreissena polymorpha foot protein), with apparent m(r) values of 76 and 26 k, respectively, contain 3,4-dihydroxyphenylalanine (dopa) int ...19938180628
uneven distribution of enamel in the tooth crown of a plains zebra (equus quagga).unworn teeth of herbivorous mammals are not immediately functional. they have to be partially worn to expose enamel ridges which can then act as shear-cutting blades to break the food down. we use the plains zebra (equus quagga) as a hypsodont, herbivorous model organism to investigate how initial wear of the tooth crown is controlled by underlying structures. we find that the enamel proportion is smaller at the apical half of the tooth crown in all upper tooth positions and suggest that lower e ...201526082860
host social rank and parasites: plains zebra (equus quagga) and intestinal helminths in uganda.the main aim of this study was to evaluate the relationship between the social hierarchy of plain zebra, equus quagga, and the level of parasitism. for the study 141 fecal samples from the same number of animals were collected within the two major populations of e. quagga of uganda (lake mburo conservation area and kidepo valley national park). quantitative (eggs per gram of feces) and qualitative parasite assessment were performed with standard methods. the relationship between parasite burden ...201222521976
the symbiotic intestinal ciliates and the evolution of their hosts.the evolution of sophisticated differentiations of the gastro-intestinal tract enabled herbivorous mammals to digest dietary cellulose and hemicellulose with the aid of a complex anaerobic microbiota. distinctive symbiotic ciliates, which are unique to this habitat, are the largest representatives of this microbial community. analyses of a total of 484 different 18s rrna genes show that extremely complex, but related ciliate communities can occur in the rumen of cattle, sheep, goats and red deer ...201424703617
comparative analyses of tooth wear in free-ranging and captive wild equids.captive breeding has played a crucial role in the conservation of threatened equid species. grazing ruminants and rhinoceros in captivity have less abrasion-dominated tooth wear than their free-ranging conspecifics, with potential negative consequences for their health. however, a similar study on wild equids in captivity is missing.201625557934
rapid molecular detection of invasive species in ballast and harbor water by integrating environmental dna and light transmission spectroscopy.invasive species introduced via the ballast water of commercial ships cause enormous environmental and economic damage worldwide. accurate monitoring for these often microscopic and morphologically indistinguishable species is challenging but critical for mitigating damages. we apply edna sampling, which involves the filtering and subsequent dna extraction of microscopic bits of tissue suspended in water, to ballast and harbor water sampled during a commercial ship's 1400 km voyage through the n ...201525686279
toxic and nutrient element concentrations in soft tissues of zebra and quagga mussels from lakes erie and ontario.zebra and quagga mussels were collected from lakes erie and ontario in 1997 and the soft mussel tissues were analyzed for ca, cd, cr, cu, fe, hg, k, mg, mn, mo, na, ni, pb, se, sr, v and zn. no consistent relationships were apparent when comparing element concentrations in soft mussel tissues and mussel type, size range or sampling location. literature dealing with the absorption of metals by both mussel types is reviewed.200010789974
[the birth of a zebra (equus quagga böhmi matschie)]. 19666011715
dna-based species detection capabilities using laser transmission spectroscopy.early detection of invasive species is critical for effective biocontrol to mitigate potential ecological and economic damage. laser transmission spectroscopy (lts) is a powerful solution offering real-time, dna-based species detection in the field. lts can measure the size, shape and number of nanoparticles in a solution and was used here to detect size shifts resulting from hybridization of the polymerase chain reaction product to nanoparticles functionalized with species-specific oligonucleot ...201323015524
quantifying quagga mussel veliger abundance and distribution in copper basin reservoir (california) using acoustic backscatter.quagga mussels (dreissena bugensis) have been linked to oligotrophication of lakes, alteration of aquatic food webs, and fouling of infrastructure associated with water supply and power generation, causing potentially billions of dollars in direct and indirect damages. understanding their abundance and distribution is key in slowing their advance, assessing their potential impacts, and evaluating effectiveness of control strategies. volume backscatter strength (sv) measurements at 201- and 430-k ...201121906773
the effect of uv-c exposure on larval survival of the dreissenid quagga mussel.the rapid spread of quagga mussels (dreissena rostriformis bugensis) has lead to their invasion of lake mead, nevada, the largest reservoir in north america and partially responsible for providing water to millions of people in the southwest. current strategies for mitigating the growth and spread of quagga mussels primarily include physical and chemical means of removing adults within water treatment, delivery, and hydropower facilities. in the present study, germicidal ultraviolet light (uv-c) ...201526186734
the complete mitochondrial genome of zebrias quagga (pleuronectiformes: soleidae).zebrias quagga (soleoidei, soleidae) is a sort of small and medium-sized commercial flatfish, characterized by both eyes on the right side of the body and with a dark brown short tentacle on each eye. in this paper, the complete mitogenome sequence of z. quagga was first determined, which is 17,045 bp in length and contains 13 protein-coding genes, two rrna genes, 22 trna genes, as well as a control region (cr) and a l-strand replication origin (ol). gene contents, locations, and orders are iden ...201624983153
do invasive quagga mussels alter co2 dynamics in the laurentian great lakes?the laurentian great lakes have experienced unprecedented ecological and environmental changes, especially after the introduction of invasive quagga mussel (dreissena rostriformis bugensis). while impacts on ecological functions have been widely recognized, the response of carbon dynamics to invasive species remains largely unknown. we report new co2 data showing significant increases in pco2 (up to 800 μatm in lake michigan) and co2 emission fluxes in most of the great lakes compared to those p ...201627996017
seasonal and size-related variation of subcellular biomarkers in quagga mussels (dreissena bugensis) inhabiting sites affected by moderate contamination with complex mixtures of pollutants.the size-related differences in subcellular biomarker responses were assessed in dreissena bugensis mussels inhabiting harbours moderately affected by pollution with complex mixtures of heavy metals and polycyclic aromatic hydrocarbons (pahs). adult d. bugensis samples were collected from three harbours of lake balaton (hungary) characterized by moderate shipping activity, and as reference site, from a highly protected remote area of the lake. biomarkers of exposure (metallothioneins (mts), etho ...201627329477
evaluation of the natural product antifoulant, zosteric acid, for preventing the attachment of quagga mussels--a preliminary study.the effectiveness of zosteric acid, a natural antifoulant from the marine seagrass zostera marina, in preventing the attachment of quagga mussels, a biofouling bivalve, was investigated. animals were exposed to water containing zosteric acid ranging from 0 to 1000 ppm, and their attachment to the container glass walls was tracked with time. 500 ppm zosteric acid was not effective at detaching animals that had already attached, but was able to prevent the attachment of most unattached animals for ...201221861646
incidental oligotrophication of north american great lakes.phytoplankton production is an important factor in determining both ecosystem stability and the provision of ecosystem goods and services. the expansive and economically important north american great lakes are subjected to multiple stressors and understanding their responses to those stresses is important for understanding system-wide ecological controls. here we show gradual increases in spring silica concentration (an indicator of decreasing growth of the dominant diatoms) in all basins of la ...201121417221
horizon scanning for invasive alien species with the potential to threaten biodiversity in great britain.invasive alien species (ias) are considered one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change. horizon scanning, the systematic examination of future potential threats and opportunities, leading to prioritization of ias threats is seen as an essential component of ias management. our aim was to consider ias that were likely to impact on native biodiversity but were not yet established in the wild in great britain. to achieve this, w ...201424839235
predator diversity effects in an exotic freshwater food web.cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. these effects can be both direct through removal of herbivores [density-mediated indirect interactions (dmiis)] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (tmiis)]. how the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. ...201323991126
annotated type catalogue of the orthalicoidea (mollusca, gastropoda) in the museum für naturkunde, berlin.the type status is described of 96 taxa classified within the superfamily orthalicoidea and present in the mollusca collection of the museum für naturkunde der humboldt-universität zu berlin. lectotypes are designated for the following taxa: orthalicus elegans rolle, 1895; bulimus maranhonensis albers, 1854; orthalicus nobilis rolle, 1895; orthalichus tricinctus martens, 1893. orthalicus sphinx tresmariae is introduced as new name for zebra sphinx turrita strebel, 1909, not zebra quagga turrita ...201323794831
elucidating causes of diporeia decline in the great lakes via metabolomics: physiological responses after exposure to different stressors.the benthic macroinvertebrate diporeia spp. have been extirpated from many areas of the laurentian great lakes, but the mechanisms underlying such declines are not fully understood. diporeia declines coinciding with the invasion of exotic dreissenid mussels (zebra and quagga) have led to the hypothesis that diporeia declines are a result of decreased food availability from increasing competition with dreissenids for diatoms. there is additional evidence that diporeia are negatively affected when ...201323434781
temperature- and turbidity-dependent competitive interactions between invasive freshwater mussels.we develop a staged-structured population model that describes the competitive dynamics of two functionally similar, congeneric invasive species: zebra mussels and quagga mussels. the model assumes that the population survival rates are functions of temperature and turbidity, and that the two species compete for food. the stability analysis of the model yields conditions on net reproductive rates and intrinsic growth rates that lead to competitive exclusion. the model predicts quagga mussel domi ...201626842390
spatial distribution of proteins in the quagga mussel adhesive apparatus.the invasive freshwater mollusc dreissena bugensis (quagga mussel) sticks to underwater surfaces via a proteinacious 'anchor' (byssus), consisting of a series of threads linked to adhesive plaques. this adhesion results in the biofouling of crucial underwater industry infrastructure, yet little is known about the proteins responsible for the adhesion. here the identification of byssal proteins extracted from freshly secreted byssal material is described. several new byssal proteins were observed ...201626825294
proximate and fatty acid composition of zebra (equus quagga burchellii) muscle and subcutaneous fat.the meat from african game species is healthy, naturally produced and increasingly popular with consumers. among these species, zebra (equus quagga burchellii) are growing in number in south africa, with the meat from surplus animals holding potential to contribute to food security and economic stability. despite being consumed locally and globally, little information exists on the composition of zebra meat. this study aimed to determine the proximate composition of zebra meat as well as the fat ...201626777284
mercury concentrations in quagga mussels, dreissena bugensis, from lakes mead, mohave and havasu.the recent invasion of the dressenid species, the quagga mussel, dreissena bugensis, into lakes mead, mohave and havasu has raised questions about their ability to alter contaminant cycling. mussels were collected from 25 locations in the three lakes. the overall average was 0.036 +/- 0.016 microg g(-1) hg dry wt. the range of the three lakes was from 0.014-0.093 microg g(-1) hg dry wt. there were no significant differences in mercury concentrations among the three lakes (f = 0.07; p = 0.794). f ...201020224976
revising the recent evolutionary history of equids using ancient dna.the rich fossil record of the family equidae (mammalia: perissodactyla) over the past 55 my has made it an icon for the patterns and processes of macroevolution. despite this, many aspects of equid phylogenetic relationships and taxonomy remain unresolved. recent genetic analyses of extinct equids have revealed unexpected evolutionary patterns and a need for major revisions at the generic, subgeneric, and species levels. to investigate this issue we examine 35 ancient equid specimens from four g ...200920007379
genetic diversity of invasive species in the great lakes versus their eurasian source populations: insights for risk analysis.combining dna variation data and risk assessment procedures offers important diagnostic and monitoring tools for evaluating the relative success of exotic species invasions. risk assessment may allow us to understand how the numbers of founding individuals, genetic variants, population sources, and introduction events affect successful establishment and spread. this is particularly important in habitats that are "hotbeds" for invasive species--such as the north american great lakes. this study c ...200516268948
genetic analyses from ancient dna.about 20 years ago, dna sequences were separately described from the quagga (a type of zebra) and an ancient egyptian individual. what made these dna sequences exceptional was that they were derived from 140- and 2400-year-old specimens. however, ancient dna research, defined broadly as the retrieval of dna sequences from museum specimens, archaeological finds, fossil remains, and other unusual sources of dna, only really became feasible with the advent of techniques for the enzymatic amplificat ...200415568989
successful survival, growth, and reproductive potential of quagga mussels in low calcium lake water: is there uncertainty of establishment risk?the risk of quagga mussel (dreissena rostriformis bugensis andrusov 1897) establishment into water-bodies of the western us has expanded the geographic concern regarding the ecological and economic impacts this species will have in aquatic ecosystems. thresholds based on calcium concentrations, an element critical for mussel growth and physiology, have been used as a primary predictor of quagga mussel establishment success to aid management decisions. we evaluated the invasion potential of quagg ...201526557422
parasite-mediated selection drives an immunogenetic trade-off in plains zebras (equus quagga).pathogen evasion of the host immune system is a key force driving extreme polymorphism in genes of the major histocompatibility complex (mhc). although this gene family is well characterized in structure and function, there is still much debate surrounding the mechanisms by which mhc diversity is selectively maintained. many studies have investigated relationships between mhc variation and specific pathogens, and have found mixed support for and against the hypotheses of heterozygote advantage, ...201424718761
the quagga and science: what does the future hold for this extinct zebra?quaggas, partially striped zebras from south africa, have had major impacts on science. in the 19th century, the results of mating between a quagga stallion and a horse mare influenced thinking about mechanisms of inheritance for more than 70 years. in the 20th century, tissue from a quagga yielded the first dna of an extinct organism to be cloned and sequenced. selective breeding of plains zebras in south africa has produced animals whose coat coloration resembles that of some quaggas. this rai ...201323748526
mitochondrial phylogenomics of modern and ancient equids.the genus equus is richly represented in the fossil record, yet our understanding of taxonomic relationships within this genus remains limited. to estimate the phylogenetic relationships among modern horses, zebras, asses and donkeys, we generated the first data set including complete mitochondrial sequences from all seven extant lineages within the genus equus. bayesian and maximum likelihood phylogenetic inference confirms that zebras are monophyletic within the genus, and the plains and grevy ...201323437078
lake bacterial assemblage composition is sensitive to biological disturbance caused by an invasive filter approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. here, we studied direct impacts of invasive dreissenid mussels (idms), one of many invasive filter feeders, on freshwater lake bacterioplankton. we demonstrate ...201728593195
influence of cladophora-quagga mussel assemblages on nearshore methylmercury production in lake michigan.recent spread of invasive mussels in lake michigan has altered primary productivity in the nearshore zone, resulting in proliferation of filamentous benthic green algae (cladophora glomerata). in areas of dense cladophora and quagga mussel (dreissena bugensis) assemblages, as well as in regions where sloughed cladophora accumulates, methylmercury (mehg) production is enhanced. a shoreline transect from a river mouth through waters overlying cladophora/quagga-rich zones showed that aqueous mehg c ...201526007285
effectiveness of earthtec(®) for killing invasive quagga mussels (dreissena rostriformis bugensis) and preventing their colonization in the western united states.quagga mussels (dreissena rostriformis bugensis) have created economic and ecological impacts in the western united states since their discovery in 2007. this study focuses on chemical control for preventing the spread of these mussels. the effectiveness of earthtec(®) in killing quagga mussels (adults, juveniles, and veligers) in lake mead, nevada-arizona, was evaluated over time across six concentrations: 0, 1, 5, 10, 17, and 83 ppm. one hundred percent mortality of adult and juvenile mussels ...201323194393
susceptibility of quagga mussels (dreissena rostriformis bugensis) to hot-water sprays as a means of watercraft decontamination.the recent spread of dreissenid mussels to various bodies of water in the western us has sparked interest by many state and federal agencies to develop protocols to stop further expansion. quagga mussels (dreissena rostriformis bugensis) are of particular importance as they are currently the most widespread dreissenid species in the region. this project examined the susceptibility of quagga mussels to hot-water sprays at different temperatures and durations of spray contact at lake mead (nevada- ...201121390911
invasive species. feared quagga mussel turns up in western united states. 200717255487
macromammalian faunas, biochronology and palaeoecology of the early pleistocene main quarry hominin-bearing deposits of the drimolen palaeocave system, south africa.the drimolen palaeocave system main quarry deposits (dmq) are some of the most prolific hominin and primate-bearing deposits in the fossil hominids of south africa unesco world heritage site. discovered in the 1990s, excavations into the dmq have yielded a demographically diverse sample of paranthropus robustus (including dnh 7, the most complete cranium of the species recovered to date), early homo, papio hamadryas robinsoni and cercopithecoides williamsi. alongside the hominin and primate samp ...201627114884
interspecific interference competition at the resource patch scale: do large herbivores spatially avoid elephants while accessing water?animals may anticipate and try to avoid, at some costs, physical encounters with other competitors. this may ultimately impact their foraging distribution and intake rates. such cryptic interference competition is difficult to measure in the field, and extremely little is known at the interspecific level. we tested the hypothesis that smaller species avoid larger ones because of potential costs of interference competition and hence expected them to segregate from larger competitors at the scale ...201627495127
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