Common Shrew Sorex Araneus Research Articles

Natural male hybrid common shrews with a very long chromosomal multivalent at meiosis appear not to be completely sterile.

Among 36 known chromosomal hybrid zones of the common shrew Sorex araneus, the Moscow-Seliger hybrid zone is of special interest because inter-racial complex heterozygotes (F1 hybrids) produce the longest meiotic configuration, consisting of 11 chromosomes with monobrachial homology (undecavalent or chain-of-eleven: CXI). Different studies suggest that such a multivalent may negatively affect meiotic progression and in general should significantly reduce fertility of hybrids. In this work, by immunocytochemical and electron microscopy methods, we investigated for the first time chromosome synapsis, recombination and meiotic silencing in pachytene spermatocytes of natural inter-racial heterozygous shrew males carrying CXI configurations. Despite some abnormalities detected in spermatocytes, such as associations of chromosomes, stretched centromeres, and the absence of recombination nodules in some arms of the multivalent, a large number of morphologically normal spermatozoa were observed. Possible low stringency of pachytene checkpoints may mean that even very long meiotic configurations do not cause complete sterility of such complex inter-racial heterozygotes.

Species Richness of Helminth Communities in Relation to Host Abundance Variations (the Case of the Common Shrew Sorex araneus)

Species Richness of Helminth Communities in Relation to Host Abundance Variations (the Case of the Common Shrew Sorex araneus)

Albinism in the common shrew Sorex araneus

AbstractAlbinism is a hypopigmentation disorder which occurs as a consequence of mutations in genes involved in melanin biosynthesis. It is recorded in many mammalian species but is generally considered to be rare in natural populations. Here, we describe a fully albino individual of the common shrew Sorex araneus found in south-western Poland. We also present previous findings of albino specimens of this species in Europe. Since the 1960s, there have only been three confirmed records of wholly albino individuals of common shrews in mainland Europe; however, albinism has been recorded more frequently in this species from Britain. In other shrew species, wholly albino individuals are also recorded very rarely.

Channelized Karyotype Evolution of the Common Shrew Sorex araneus (Mammalia)

Channelized Karyotype Evolution of the Common Shrew Sorex araneus (Mammalia)

Small mammals in the diet of the tawny owl Strix aluco in selected sites of the Biebrza Basin and Knyszyn Forest in north-eastern Poland.

The analysis of pellets of the tawny owl Strix aluco collected in the years 2009–2023 in 22 sites (ten in the Biebrza Basin and twelve in Knyszyn Forest) allowed for finding four species of Soricomorpha, nine species of Chiroptera and fifteen species of Rodentia (4, 5 and 12 in the Biebrza Basin and 4, 7 and 13 in Knyszyn Forest, respectively). Most common and most frequently caught by owls were: the bank vole Clethrionomys glareolus, the yellow-necked mouse Apodemus flavicollis and the common shrew Sorex araneus. Valuable species of bats included the pond bat Myotis dasycneme and the western barbastelle Barbastella barbastellus noted in Knyszyn Forest. Rare rodents found in both study areas were: the northern birch mouse Sicista betulina and the common dormouse Muscardinus avellanarius while the forest dormouse Dryomys nitedula was noted only in Knyszyn Forest. The European water vole Arvicola amphibius commonly noted in the Biebrza Basin was not found in Knyszyn Forest. On the contrary, the common pine vole Microtus subterraneus was reecorded only in Knyszyn Forest.

Fluctuating fine-scale spatial genetic structure in the common shrews (Eulipotyphla, Mammalia).

The spatial genetic structure is a topical issue in the studies of various aspects of ecology and evolution. Using the multilocus autocorrelation method with hypervariable microsatellite genetic markers, we investigated a fine-scale pattern of genetic structure in 5 local populations of the common shrew Sorex araneus separated by distances of 300-1000 m (the Moscow chromosomal race). Spatial genetic autocorrelation analysis based on 5 microsatellite loci (expected heterozygosity >0.79) with 90 alleles revealed a consistent pattern of significant positive genetic structure. By testing the autocorrelation at multiple scales from 25 to 500 m, we found that positive spatial genetic structure is detectable in distance classes of <500 m. The weaker spatial genetic structure positively correlated with a higher ratio of nonresident individuals to residents' activity (number of captures). In contrast to nonresident animals, the residents demonstrated prominent genetic structure. Genetic difference (FST ) between the populations was significant (0.016-0.051) and comparable with that between populations of different races analyzed previously (0.016-0.038). FST was not associated with geographic distance. These demographic patterns allowed us to propose a scheme of genetic-structure dynamics involving periodic appearance of more related local groups and renewal of allelic profiles from а common pool where the alleles are mixed. The scheme predicts fluctuating genetic structure and random similar differences among local populations.

Repellent effect of synanthropic house mouse urine odor on small forest mammals.

In this study, we examined the effect of synanthropic house mouse (Mus musculus) urine odor on catching probability of small mammals to live traps. We conducted a series of field experiments in August 2016 and 2017 in a natural forests of the northwestern Moscow Region (Russia). Small mammals were trapped at two 4-ha fields using capture-mark-recapture technique by setting 200 live traps (100 points, 2 traps per point) within each field. One trap in each pair was odorless (control) with bait only, whereas the other one was odor-baited with 20 μL of the urine of a synanthropic house mouse. Further analysis was based on the data collected from 2 rodent species (bank vole Myodes glareolus, herb field mouse Apodemus uralensis) and 3 shrew species (common shrew Sorex araneus, Laxmann's shrew Sorex caecutiens, and Eurasian pygmy shrew Sorex minutus). As a result, only bank voles significantly avoided odor-baited live traps. Using generalized linear mixed models, we showed that the choice of a trap by bank voles depended on their age, whereas the probability of repeated capture to a certain live trap was related to their prior experience. We discuss the possible role of components of synanthropic house mouse urine in the population management of exoanthropic small mammals.

New cestode species of the genus Neoskrjabinolepis Spassky, 1947 (Cyclophyllidea: Hymenolepididae) from the Common Shrew (Sorex araneus L.) in Europe.

Neoskrjabinolepis (Neoskrjabinolepis) yanchevi n. sp. is described from common shrews Sorex araneus L. (Eulipotyphla: Soricidae) from Pirin Mts., Bulgaria (type-locality) and Russia (Arkhangelskaya Oblast'). The new species is characterised by ten rostellar hooks 37-40 μm long and possessing claw-like blades with crooked middle parts and well-developed epiphyseal thickenings of handles; a whip-shaped cirrus, 80-100 μm long, consisting of basal region with numerous small, rosethorn-shaped spines, and middle and distal regions armed with fine, needle-shaped spines; vagina provided with sphincter close to its orifice, with copulatory and conductive part not clearly distinct from one another; 40-50 eggs per gravid uterus. The species is differentiated from the remaining 4 species of the nominotypical subgenus of the genus Neoskrjabinolepis, which are parasites of the Palaearctic shrews of the genus Sorex.

Demodex crocidurae, a New Demodecid Mite (Acariformes: Prostigmata) Parasitizing the Lesser White-Toothed Shrew and a Redescription of Demodex talpae from European Mole with Data on Parasitism in Soricomorpha.

Simple SummaryThis paper describes a new species, Demodex crocidurae, inhabiting the hairy skin of Crocidura suaveolens. It also redescribes the most morphologically similar form: Demodex talpae from Talpa europaea, a species known from Hirst’s 1921 description. Following a differential diagnosis, it was concluded that these are separate species with different features important in the taxonomy of Demodecidae, inhabiting analogous microhabitats in different species of hosts.Only six parasitic species of Demodecidae mite have thus far been described from the Soricomorpha, these being associated with the common shrew Sorex araneus Linnaeus, 1758, and the Mediterranean water shrew Neomys anomalus Cabrera, 1907 (two species from each host), and with the lesser white-toothed shrew Crocidura suaveolens (Pallas, 1811) and the European mole Talpa europaea Linnaeus, 1758 (one from each host species). Presently, Demodex crocidurae, a new species, has been described from the territory of Poland for C. suaveolens; in order to confirm its validity, it was necessary to redescribe D. talpae Hirst, 1921, from T. europaea, a demodecid species first described by Hirst in 1921 from England and then noted only in Poland. Both species colonized the hairy skin of the body in their hosts, where no disease symptoms of infestation were observed. However, D. crocidurae showed higher infection parameters (prevalence 100%, mean intensity 11.7, intensity range 3–26 individuals) than those of D. talpae (30.0%, 4.7, 2.0–8.0), possibly due to different host biology.

Lunar illumination shapes small mammal activity in lowland agricultural landscapes

The behavioural patterns of small mammalian prey species have been shown to be widely impacted by predator avoidance. Cues to avoid predation may come from the predator itself or environmental cues, such as moonlight and available vegetative cover. We investigated how the activity of the bank vole Myodes glareolus, field vole Microtus agrestis, wood mouse Apodemus sylvaticus and the common shrew Sorex araneus were impacted by changes in habitat and lunar light conditions across a range of habitats (mainly grassland protected sites) in Lincolnshire (UK). Microhabitat vegetation density as well as weather conditions were recorded across all trap sites, with Longworth traps set overnight and the successfully captured species recorded the following morning. Overnight temperature was found to positively influence capture rate across all species. The lunar phase was found to significantly impact capture rate, with the gibbous lunar phase providing the highest capture rate across species. The interaction between illumination and vegetation density was also found to impact activity levels in the bank vole and wood mouse, with the bank vole showing higher activity in thick vegetation at low light levels and across habitats at higher light levels, whereas wood mice were more often captured in intermediate cover at low and intermediate illumination but across a range of habitats at brighter illumination. In combination, it suggests that small mammal activity is altered to potentially reduce predation risk. However, in this community at least, brighter lunar illumination leads to increase activity.

A Study of Reproduction of the Common Shrew (Sorex araneus) at the Northern Periphery of Its Range

A Study of Reproduction of the Common Shrew (Sorex araneus) at the Northern Periphery of Its Range

Seewis hantavirus in common shrew (Sorex araneus) in Sweden

BackgroundRodent borne hantaviruses are emerging viruses infecting humans through inhalation. They cause hemorrhagic fever with renal syndrome and hemorrhagic cardiopulmonary syndrome. Recently, hantaviruses have been detected in other small mammals such as Soricomorpha (shrews, moles) and Chiroptera (bats), suggested as reservoirs for potential pandemic viruses and to play a role in the evolution of hantaviruses. It is important to study the global virome in different reservoirs, therefore our aim was to investigate whether shrews in Sweden carried any hantaviruses. Moreover, to accurately determine the host species, we developed a molecular method for identification of shrews.MethodShrews (n = 198), caught during 1998 in Sweden, were screened with a pan-hantavirus PCR using primers from a conserved region of the large genome segment. In addition to morphological typing of shrews, we developed a molecular based typing method using sequencing of the mitochondrial cytochrome C oxidase I (COI) and cytochrome B (CytB) genes. PCR amplified hantavirus and shrew fragments were sequenced and phylogenetically analysed.ResultsHantavirus RNA was detected in three shrews. Sequencing identified the virus as Seewis hantavirus (SWSV), most closely related to previous isolates from Finland and Russia. All three SWSV sequences were retrieved from common shrews (Sorex araneus) sampled in Västerbotten County, Sweden. The genetic assay for shrew identification was able to identify native Swedish shrew species, and the genetic typing of the Swedish common shrews revealed that they were most similar to common shrews from Russia.ConclusionWe detected SWSV RNA in Swedish common shrew samples and developed a genetic assay for shrew identification based on the COI and CytB genes. This was the first report of presence of hantavirus in Swedish shrews.

Intraspecific variation of body size in fleas: effects of host sex and flea phenology.

We investigated the effects of host sex and flea phenology (estimated as periods of high versus low abundance) on individual body size in four fleas of small mammals. Amalaraeus penicilliger and Ctenophthalmus uncinatus are ectoparasites of the bank vole Myodes glareolus, whereas Doratopsylla dasycnema and Palaeopsylla soricis are ectoparasites of the common shrew Sorex araneus. We found significant effects of host sex and phenology on the body size of all flea species, although there was no general trend in the directions of these effects. Larger A. penicilliger were found on female hosts, whereas larger P. soricis were found on male hosts. In the remaining species, larger fleas were collected from male hosts during periods of high abundance (male C. uncinatus and female D. dasycnema) and from female hosts during periods of low abundance (male C. uncinatus). Regarding phenology, larger fleas were recorded during periods of either high (A. penicilliger, C. uncinatus, D. dasycnema) or low (C. uncinatus, P. soricis) abundance, but this depended on flea and/or host sex. We conclude that the directions of the host sex and phenology effects varied between flea species. Furthermore, the direction of the host sex effect was mediated by the effect of phenology and vice versa.

Notable homologous variation in chromosomal races of the common shrew.

This paper is a review of the rare phenomenon of chromosome intraspecies variation manifested in monobrachial homology series in the comprehensively investigated karyotype of the common shrew Sorex araneus Linnaeus, 1758 (Eulipotyphla, Mammalia). The detailed dataset on the account of this mammalian species was drawn from the recently published monograph by Searle et al. (2019) “Shrews, Chromosomes and Speciation”. The parallels to the law of homologous series in variation by Nikolai Vavilov are discussed.

A never-ending story of the common shrew: searching for the origin.

A range-wide phylogeographic study of the common shrew Sorex araneus was performed using the concatenation of cytb and ND2 mitochondrial genes. The data support two major lineages, one of which (European haplogroup) is distributed continuously from West Europe to West Siberia; the other (Siberian haplogroup) is found in two non-adjacent areas: in central Siberia and in southern Finland and Karelia. Several smaller subclades (East European, Balkan, and West Siberian) were identified within the European lineage. Ancestral area reconstructions were performed under the maximum parsimony criterion using the algorithm that was designed to analyze landmark data. The results suggest that the last common ancestor of the common shrew inhabited the Balkans or the Danubian-Carpathian area. The results of demographic analyses are consistent with the hypothesis of recent expansion throughout the entire distribution range. The genetic diversity indices and the expansion time estimates were higher in the western part of the range. Cumulatively, these findings support the hypothesis that during the Last Glacial Maximum, the range of the common shrew was restricted to a single refugium in Southeastern Europe.

Assortative Mating in Hybrid Zones between Chromosomal Races of the Common Shrew Sorex araneus L. (Soricidae, Soricomorpha)

The article is devoted to quantitative characteristics of assortative mating (R) as indicator of “reinforcement” in 12 hybrid zones between chromosomal races of the common shrew, Sorexaraneus L. The Wahlund effect in hybrid population and its potential reduction are examined. In hybrid zones with heterozygotes CIV, CV, and RIV, the R index varies within 0.23–0.59. In hybrid zones with more complex heterozygotes (RVI, CIX–CXI), it exceeds 0.82. Gene flow in the hybrid zone is interrupted at R > 0.99. Assortative mating reduces gene flow and also maintains genotype stability in hybrid populations.

Evidence of Echolocation in the Common Shrew from Molecular Convergence with Other Echolocating Mammals.

Along with sophisticated echolocation found in bats and toothed whales, the common shrew (Sorex araneus) was confirmed to possess echolocation ability based on behavioral and experimental evidence such as high-frequency twittering and close-range spatial orientation. However, whether echolocation in the common shrew is convergent with bats and dolphins at the molecular level remains poorly understood. In this study, we gathered the coding region sequences of 11 hearing-related genes from genome data and previous studies. Convergent evolutionary analyses identified 13 amino acid residues (seven in CDH23, five in OTOF, and one in PRESTIN) under strong convergent evolution shared among the common shrew and other echolocating mammals (bats and dolphins). Furthermore, a phylogenetic tree was constructed based on the combined amino acid dataset of convergent/parallel substitutions, sites with parallel radical property changes, and sites supporting echolocator-convergence; it supported the converged topology of the simple echolocator Sorex araneus and sophisticated echolocating bats with high posterior probability. This study gives evidence at the molecular level that the common shrew echolocate and provides novel insights into the convergent evolution between the common shrew and bats and dolphins.

Hybrid Zone between the Sok and Serov Chromosomal Races of the Common Shrew Sorex araneus (Lipotyphla, Mammalia) in European Russia

Analysis of the frequencies of karyotypic variants in the hybrid zone between the Sok and Serov chromosomal races of the common shrew Sorex araneus revealed that the zone has a complex configuration. A large part of the contact zone is located in a monotonous mid taiga zone, where there are no significant barriers to limit dispersion of shrews. Another part of the zone runs along the Pechora River (Komi Republic). Analysis of distribution of the diagnostic chromosomes on a transect along the Pechora River showed that the hybrid zone could be described by opposing metacentric clines. Individuals of both pure Sok and Serov races, as well as F1 hybrids, were found only on the left bank of the Pechora River. The right bank was occupied only by the Serov race, and F1 hybrids were rare there. The observed number of interracial hybrids in the center of the zone does not differ from that expected in the case of random breeding. This allows us to define this zone as unimodal. The standard width of the zone is about 40 km. This is considerably higher than all known cases of hybrid zones with the same level of karyotypic differences between parental races: two pairs of diagnostic metacentric chromosomes with monobrachial homology. We discuss possible causes of this phenomenon.

Role of Population Structuring in the Formation of Karyotypic Diversity of the Common Shrew Sorex araneus (Lipotyphla, Mammalia)

In this review, we describe karyotypic, morphological, and genetic structuring of population in the common shrew Sorex araneus (Lipotyphla, Mammalia), and try to explain some unclear and contradictory aspects of this structuring on the basis of population approach. The subdivision of this species into more than 76 parapatric chromosomal races does not correspond to its morphological and genetic structuring. Chromosomal hybrid zones are formed in the areas of contact between the races. The frequency of interracial F1 hybrids is low in nature, but we have shown that mating between different races in captivity occurs quite readily, although the postnatal survival of hybrids is reduced. We suggest that this species is subdivided into relatively small populations characterized by the unity of functioning, which is ensured by the predominant dispersal of individuals from each of the populations within their population space. It should also be emphasized that the main provisions set forth by Stanislav S. Shvarts in his conceptual monograph The Evolutionary Ecology of Animals are still relevant today.

HELMINTHS OF THE COMMON SHREW SOREX ARANEUS IN THE KIVACH NATURE RESERVE

This study is a continuation of the research for the inventory of the parasite fauna of small mammals in nature reserves and parks of the North-West European Russia. Data are presented on the species composition and relative abundance of helminths in the common shrew Sorex araneus in the Kivach Strict Nature Reserve (Republic of Karelia, Russia). Findings from the surveys include 21 species of helminths belonging to three systematic groups: trematodes - Brachylaima fulvum, Rubenstrema exasperatum, cestodes Ditestolepis diaphana, Gulyaevolepis tripartita, Neoskrjabinolepis schaldybini, N. singularis, Staphylocystis furcata, Vigisolepis spinulosa, Dilepis undula, Hepatocestus hepaticus, Monocercus arionis, and nematodes - Aonchotheca kutori, Liniscus incrassatus, Eucoleus oesophagicola, Soboliphyme soricis, Parastrongyloides winchesi, Longistriata codrus, L. didas, L. depressa and Porrocaecum depressum, Porrocaecum sp. Representatives of the Palaearctic faunal complex prevail among the helminths parasitic in the common shrew (85 %). Eight species of parasitic worms were recorded in the common shrew from the territory of the Kivach nature reserve for the first time: R. exasperatum, B. fulvum, N. singularis, S. furcata, V. spinulosa, L. incrassatus, E. ophagicola, P. winchesi. These species are typical representatives of the helminth fauna of the common shrew in the middle taiga subzone of Karelia.