Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rodentia”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed2002

Laboratory evaluation of fipronil and imidacloprid topical insecticides for control of the plague vector Oropsylla montana (Siphonaptera: Ceratophyllidae) on california ground squirrels (Rodentia: Sciuridae).

Two insecticides, fipronil and imidacloprid, were evaluated for efficacy and longevity against Oropsylla montana (Baker), the most important vector of plague in California. Wild-caught California ground squirrels, Spermophilus beecheyi (Richardson), were individually housed in the laboratory to serve as natural hosts to O. montana and for on-animal insecticide trials. Several concentrations oftechnical grade fipronil and imidacloprid in acetone were applied to samples of clean rodent bedding to determine residual activity and longevity against fleas. Immature and adult cat fleas, Ctenocephalides felis (Bouche), were used as representative fleas for periodic assays in place of less fecund O. montana. Toxicity of treated bedding did not decrease significantly for 1 yr at all applied concentrations. Fipronil provided 100% kill for at least 1 yr at > or = 100 ppm, whereas imidacloprid required 10,000 ppm for similar performance. Laboratory squirrels were treated with topical formulations of fipronil (Frontline Top Spot) and imidacloprid (Advantage Flea Adulticide) at a dosage rate of 15 mg/kg and evaluated for residual activity every 2 wk against adult O. montana. Residual activity was determined by percent recovery of O. montana adults released on treated and untreated animals after 48 h. Frontline provided 100% kill of adult fleas for at least 10 wk, and up to 26 wk on one animal. Advantage failed to provide 100% kill of adult fleas at 2 wk, with complete loss of efficacy by week 6. Concurrent assays with bedding samples from squirrel nest boxes showed negligible toxicity transfer from treated animals to nest bedding.

Animals↗
PubMed2004

Systematics of the genus Sciurocheyla (Acari: Cheyletidae), parasites of tropical squirrels (Rodentia: Sciuridae).

Two genera of parasitic cheyletid mites, Smileycheles Fain, 1979 (monotypic) and Thryonomycheyla Fain, 1972 (two species), are synonymized with the genus Sciurocheyla Volgin, 1969. An emended diagnosis of the genus Sciurocheyla is provided. Sciurocheyla squamosa (Domrow & Baker, 1963), type species of the genus, and Sciurocheyla camerounensis (Fain, 1979), new combination, are redescribed. Females, males, teleo- and protonymphs of Sciurocheyla funisciurus, new species, collected from Funisciurus pyrrohopus F. Cuvier in tropical Africa are described and illustrated.

Acari↗
PubMed2000

Pterygodermatites (Mesopectines) senegalensis n. sp. (Nematoda, Rictulariidae), a parasite of Mastomys huberti (Rodentia, Muridae) in Senegal.

Pterygodermatites (Mesopectines) senegalensis n. sp. (Nematoda: Rictulariidae) is described from Mastomys huberti in Senegal. It differs from other species of the subgenus by the morphology of the head, which exhibits 4 simple cephalic papillae and a nearly axial buccal opening, the length of the spicules, the number of precloacal cuticular formations, and the absence of cephalic apophyses.

Animals↗
PubMed2000

Two new species of Litomosoides (Nematoda: Filarioidea) in Sigmodontines (Rodentia: Muridae) from Rio de La Plata marshland, Argentina.

Two new species of coelomic filarioid belonging to Litomosoides are described from sigmodontine murids from the Rio de La Plata marshland, Argentina. Litomosoides bonaerensis n. sp., a parasite of Oligoryzomys delticola, belongs to the carinii group and is close to L. silvai, which differs by the head and tail papillae, buccal capsule and cavity, area rugosa, and morphology of the microfilaria. Litomosoides oxymycteri n. sp., from Oxymycterus rufus, belongs to the sigmodontis group. Differential diagnosis is based on the morphology of the buccal capsule, the head and tail papillae, and microfilaria. The ectoparasitic gamasid Ornithonyssus bacoti, in which several Litomosoides species develop, has been recovered from sigmodontines trapped in the study.

Animals↗
PubMed2000

Phylogenetic relationships among species of Stilestrongylus Freitas, Lent and Almeida, 1937 (Trichostrongyloidea: Heligmonellidae: Nippostrongylinae), parasites of myomorph rodents (Rodentia: Muridae) in the Neotropics.

The phylogenetic relationships of 14 species of Stilestrongylus were analyzed using the comparative morphology of 21 characters. We obtained 2 shortest trees of 50 steps, with a consistency index of 0.540 and 25 apomorphic character states. Ingroup monophyly was supported on these trees by 2 and 3 synapomorphies, respectively, and the ingroup was defined by the following characters: greater number of ventral ridges relative to the number of ridges dorsally, asymmetric bursa, and externodorsal rays differing in size. Sister-group relationships among Stilestrongylus and the other genera designated as outgroups are relatively consistent with those postulated by Durette-Desset's in a classification of the Nippostrongylinae. The ancestor of the species groups comprising Hassalstrongylus, Guerrerostrongylus, and Stilestrongylus originated and diversified in murids in the Neotropical region. Species of Hassalstrongylus occur in rodents between southeastern North America and the eastern part of South America (Brazil and Argentina), whereas species of Guerrerostrongylus and Stilestrongylus diversified exclusively in rodents in the Neotropics.

Animals↗
PubMed2001

A new species of sucking louse (Insecta, Anoplura) parasitic on Auliscomys (Mammalia, Rodentia) in Argentina.

Hoplopleura auliscomydis n. sp. is described based on specimens collected from Auliscomys micropus (Waterhouse 1837), from Collń Curá, Neuquén Province, Argentina. Descriptions are provided for the holotype male, female, first nymphal instar, external architecture of eggs (by scanning electron microscopy), and sites of oviposition, providing differences from its close relative Hoplopleura neotomydis Castro, González, and Cicchino, 1995. The geographical ranges of these 2 species are restricted to the Neuquén Province in Argentina. A key to the 9 species of the Hoplopleura travassosi species-group recorded in Argentina is also given.

Animals↗
PubMed2001

Fecundity of Hoplopleura scapteromydis (Phthiraptera: Anoplura, Hoplopleuridae), ectoparasite of Scapteromys aquaticus (Rodentia: Muridae) in Rio de La Plata marshlands, Argentina.

Density and age structure of lice collected from captured Scapteromys aquaticus rodents were studied to estimate the fecundity of Hoplopleura scapteromydis. The number of eggs with a visible embryo inside (E), nymphs (N), adult males (AM), and adult females (AF) were recorded for each rodent. For the ith rodent, the fecundity of H. scapteromydis, F(i), was estimated as F(i) = [[E(i) + N(i)]/2]/AF(i)/T, where T represents the period of preimaginal development (unknown and arbitrarily considered as T = 1), and the sex ratio of the preimaginal stages was supposed to be 1:1. In order to look for density-dependent effects, F(i) was plotted against AM(i), this being an independent estimation of infrapopulation density. The number of rodents suitable for AF and AM calculations was 38 (57% of the parasitized animals). Almost 95% had a low-to-moderate louse burden (1 < AM < 30) and were captured every season, whereas only 3% had a heavy (61 < AM < 70, captured in winter) or very heavy (AM > 80, captured in summer) louse burden. The extreme values of F were 0.63 and 18 (1.3 and 36 if both sexes were considered). High-to-moderate F-values (F > 5) were estimated in only 5 rodents that exhibited low louse density, whereas low F-values (F < 5) were found at all louse densities. Notwithstanding the tendency toward an inverse relationship between fecundity and infrapopulation density, the correlation was not significantly different from 0.

Animals↗
PubMed2005

Three new species of Eimeria (Apicomplexa: Eimeriidae) from the silvery mole rat Heliophobius argenteocinereus Peters, 1846 (Rodentia: Bathyergidae) from Malawi.

Three species of Eimeria Schneider are described from feces of the African bathyergid rodent, Heliophobius argenteocinereus, from Malawi. Oocysts of Eimeria heliophobii n. sp. are broadly ellipsoidal; 27.9 (22-31) x 22.3 (18-24.5) microm with a brownish, heavily pitted oocyst wall, and vacuolar oocyst residuum. Sporocysts are oval, 12.8 (12-14) x 8.4 (8-9) microm with Stieda and substieda bodies. Eimeria nafuko n. sp. has subspherical oocysts; 15.5 (15-16) x 12.8 (12-13) microm with a smooth, colorless oocyst wall. Sporocysts are oval, 9.2 (9-10) x 5.3 (5-6) microm, with a small Stieda body; the substieda body is not visible. Oocysts of Eimeria yamikamiae n. sp. are broadly ellipsoidal to subspherical; 20.8 (19-22) x 17.5 (15.5-19) microm, with slightly yellowish, very faintly pitted oocyst wall. The majority of oocysts contained a single spherical vesicular oocyst residuum and numerous very small granules. Sporocysts are oval, 10.7 (10-11) x 6.8. (6-7) microm, with a dome -like Stieda body and a subspherical to lentil-like substieda body. Typically, infected rodents shed oocysts of more than 1 species of Eimeria.

Animals↗
PubMed2006

A new species of Sciurodendrium (Nematoda: Heligmonellidae) in Sciurus aureogaster (Rodentia: Sciuridae) from Morelos, Mexico.

Sciurodendrium bravohollisae n. sp. (Heligmonellidae) is described as an intestinal parasite of 2 squirrels, Sciurus aureogaster Cuvier, 1829, collected from Los Robles, Municipio de Tlalnepantla, Morelos State, Mexico. The new species differs from all other congeners in possessing a very well-developed and sacciform genital cone. This is the seventh species described for the genus and the first one recorded in Mexico.

Animals↗
PubMed1996

Phylogenetic relationships among Japanese species of the family Sciuridae (Mammalia, Rodentia), inferred from nucleotide sequences of mitochondrial 12S ribosomal RNA genes.

In order to investigate phylogenetic relationships of the family Sciuridae living in Japan, we sequenced partial regions (379 bases) of mitochondrial 12S rRNA genes in six species of Japanese and other Asian squirrels. Phylogenetic trees constructed by sequence data indicated that two genera of flying squirrels (Petaurista and Pteromys) were clustered in a group distinct from non-flying squirrels, suggesting a possible monophyletic relationships of these flying squirrels. The evolutionary distance between the Japanese squirrel (Sciurus lis) from Honshu island and the Eurasian red squirrel (Sciurus vulgaris) from Hokkaido island was comparable to intraspecific distances of the remaining species examined.

Animals↗
PubMed1975

Investigation on the acute toxic effect of pyrethrum on the blood glucose and of glucose administration on the acute pyrethrum toxicity in Meriones hurrianae Jerdon (Rodentia).

The effect of different doses of pyrethrum on the blood glucose level and glucose tolerance in pytethrum-administered gerbils, were investigated. Pyrethrum produces hyperglycemia and lowers the glucose tolerance indicating an impairment in the uptake and utilization of glucose. The possible reasons for these effects are discussed.

Animals↗
PubMed1983

Mastomys (rodentia: muridae) species distinguished by hemoglobin pattern differences.

Hemoglobin electrophoresis patterns were found to be reliable markers for distinguishing two species of Mastomys in Sierra Leone having 32 and 38 chromosomes. All 32-chromosome animals exhibited a single hemoglobin pattern, whereas those with 38-chromosomes had four distinguishable patterns. Both karyotypes were present throughout Sierra Leone. The 38-chromosome species was more prevalent in the Guinea savanna zone to the north, while the 32-chromosome species was most dominant in human-modified high forest areas of the eastern and southern parts of the country. In almost all situations the 32-chromosome species was more common in houses than in bush habitats; the reverse was true for Mastomys having 38 chromosomes. Analysis of hemoglobin patterns thus becomes useful for species identification, and is necessary to understand the roles of the different Mastomys forms as reservoirs of human diseases, such as Lassa fever in West Africa.

Animals↗
PubMed1999

[Allozyme differentiation of various chromosomal forms of the spotted suslik (Spermophilus suslicus Guld, 1770, Rodentia)].

Eleven enzyme and four nonenzyme protein systems controlled by 25 loci were electrophoretically analyzed in the allopatric karyotypic forms (2n = 34 and 2n = 36) of the spotted souslik Spermophilus suslicus. Genetic variability and differentiation for the forms with different chromosome sets were estimated. Two discriminative loci (Alb and Tf) for the studied chromosome forms were found. The UPGMA dendrogram was constructed, which summarizes genetic (allozyme) relationships found for the forms of the spotted souslik with different chromosome sets. Subdividing the species into two karyotypic forms was shown to be followed by differentiating these forms at the allozyme level.

Animals↗
PubMed1999

[Genetic differentiation of voles of the tribe Arvicolini (Cricetidae, Rodentia) using taxonprint analysis and polymerase chain reaction with random primers].

The variability of the genomes of ten vole species was analyzed by means of taxonomic DNA fingerprinting and polymerase chain reaction using random primers (RAPD-PCR). The dendrograms of genetic similarity between the representatives of the tribe Arvicolinae (Gray, 1821) were constructed, based on the data obtained by means of both methods. The topology of the genetic similarity dendrogram that is based on the RAPD-PCR data generally correlates with the genetic distances estimated from biochemical and karyological data. The results did not confirm the genus status of Terricola. On the other hand, the data from taxonprint analysis suggest the recognition of Lasiopodomys as a separate genus.

Animals↗
PubMedDate not supplied

[The ecology of the sibling species Microtus arvalis Pallas, 1779 and Microtus rossiaemeridionalis Ognev, 1924 (Rodentia, Cricetidae) in the Tsimlianskie sands].

Ecological features and circadian activity of the common vole sibling species were studied upon joint and separate occurrences. Both species had a similar abundance but different biotopical distribution. Microtus arvalis--chromosome form "obscurus" populated the studied territory more uniformly the studied territory. M. rossiaemeridionalis tended to occur in humid coenoses. In case of joint occurrences, the sibling species occupied different regions of biotopes and the rhythms of their activity change, as a rule, in antiphase. Separation of the spatial and temporal niches of these species is considered as possible avoidance of competition between the closely related species.

Animals↗
PubMed1999

[Genetic connections and differentiation of ground squirrels Marmotinae Pocock, 1923 (Rodentia, Sciuridae) from Palearctics].

Genetic distances between eight species of sousliks (Spermophilus) and five species of marmots (Marmota) were estimated on the basis of 39 biochemical loci. All taxa were shown to be genetically discrete. The genetic differentiation was minimal (Pfd = 11.3) between parapatric species of Palearctic sousliks of the suslicus pigmaeus group and Marmota species, intermediate (Pfd = 34.7) between allopatric sousliks species, and maximal (Pfd = 56.7) between representatives of different genera. The following trends were revealed in the geographic differentiation of the genus Spermophilus: (1) genetic similarity was associated with the geographic distance; (2) the eastern and western Palearctic phyla were markedly different genetically; (3) the eastern Palearctic forms exhibited higher differentiation than the western ones. The revealed speciation pattern is consistent with the general trend of temporal differentiation in Palearctic phyla and confirms the periodic speciation mode in the Palearctics.

Animals↗
PubMed1999

[Supernumerary chromosomes, mosaicism, and dynamics in two populations of Eastern-Asian wood mouse (Apodemus peninsulae, Rodentia) from Primorskiĭ Krai at various seasons of the year].

Karyotypes of 47 individuals of the wood mice Apodemus peninsulae from two reserves in Primorskii krai (Kedrovaya Pad' and Ussuriiskii) were studied during spring, summer, and autumn. In each population, variation in the number of B-chromosomes (2n = 48 + 0-5B) as well as the intratissue mosaicism determined by variation of the number, size and morphology of supernumerary chromosomes were described. Animals that have one dotlike B-chromosome were first described in both populations as rare variants. Individuals that have bone-marrow cell clones with two or three B-chromosomes were found to be predominant in the populations of Primorskii krai. The number of clones varied from one to three per animal. The frequency of mosaics showed seasonal variation. In the population of the Ussuriiskii reserve, a sharp increase in the frequency of animals with a stable karyotype was detected in autumn, at the phase of increased numbers. The variation for mosaicism was suggested to correlate with the population numbers in mice and to indicate the genetic differences between generations of the population.

Animals↗