| nucleotide sequence variation in the mitochondrial 12s rrna gene and the phylogeny of african mole-rats (rodentia: bathyergidae). | mitochondrial dna (mtdna) sequence variation was examined in eight taxa of the african rodent family bathyergidae, as well as in two taxa representative of the old-world hystricognathid rodent families petromyidae and thryonomyidae. a total of 812 bp, constituting domains i-iii of the 12s ribosomal rrna gene, were compared for each taxon. the high levels of intrafamilial mtdna sequence divergence observed (average 16.8, range 3.5-23.2) support an ancient origin for the five genera, 20-38 mya. th ... | 1992 | 1552839 |
| eimeria burdai sp. n. (apicomplexa: eimeriidae), a new parasite species from subterranean african silvery mole-rat, heliophobius argenteocinereus. | a new coccidian parasite of the genus eimeria schneider, 1875 is described from the subterranean african silvery mole-rat heliophobius argenteocinereus peters, 1846. oocysts of eimeria burdai sp. n. were subspherical to broadly ellipsoidal 17.8 (16-19) x 14.1 (12-15), with a shape index 1.2 (1.1-1.4). oocyst wall was bilayered, smooth and colourless, approximately 1.0 thick. outer layer was significantly thicker than inner one. a micropyle and oocyst residuum were absent. one or two ellipsoidal ... | 2000 | 10945732 |
| evidence from intron 1 of the nuclear transthyretin (prealbumin) gene for the phylogeny of african mole-rats (bathyergidae). | a 900- to 1100-bp fragment encompassing intron 1 of the nuclear transthyretin (prealbumin) gene was examined in 12 taxa of old world hystricognath rodents of the families bathyergidae, petromuridae, thryonomyidae, and hystricidae. within the bathyergidae, heterocephalus glaber (naked mole-rat) was basal, and the other east african species, heliophobius argenteocinereus (silvery mole-rat), was sister to a southern african clade containing bathyergus, cryptomys, and georychus (dune, common, and ca ... | 2000 | 10991798 |
| silvery mole-rats ( heliophobius argenteocinereus, bathyergidae) change their burrow architecture seasonally. | little is known about seasonal changes in burrowing activity and burrow architecture in subterranean african mole-rats (bathyergidae, rodentia). the solitary genus heliophobius is the least known genus of this family. we examined burrow systems of the silvery mole-rat (heliophobius argenteocinereus) in malawi in two periods of the dry season. burrow pattern was influenced by the time of the year, becoming more reticulated at the peak of the dry season when soil was dry and hard. overall digging ... | 2003 | 12955227 |
| 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, co ... | 2005 | 16419767 |
| emmonsiosis of subterranean rodents (bathyergidae, spalacidae) in africa and israel. | the presence of adiaspores of the fungal genus emmonsia was examined in the lungs of 85 mole rats representing 3 subterranean genera: blind mole rats (spalax galili and s. golani) from israel, ansell's mole-rats (cryptomys anselli) from zambia, and silvery mole-rats (heliophobius argenteocinereus) from malawi and zambia. emmonsiosis was found in 28% of the blind mole rats, 100% of the ansell's mole-rats, but in none of the silvery mole-rats. infection in african mole-rats was caused by emmonsia ... | 2005 | 16422298 |
| energetics in a solitary subterranean rodent, the silvery mole-rat, heliophobius argenteocinereus, and allometry of rmr in african mole-rats (bathyergidae). | low resting metabolic rate (rmr) in subterranean rodents used to be considered as a physiological adaptation to cope with stresses of the belowground environment. in african mole-rats (bathyergidae, rodentia), rmr was reported to be independent of body mass. this deviation from a general mammalian pattern was considered a precondition for evolution of eusociality, occurring in some bathyergids. we measured metabolic rate and thermoregulation in the silvery mole-rat, heliophobius argenteocinereus ... | 2007 | 17337221 |
| patterns of surface temperatures in two mole-rats (bathyergidae) with different social systems as revealed by ir-thermography. | furred subterranean mammals face the problem of dissipating heat to the environment because high humidity and absence of air flow in sealed belowground tunnels constrain heat loss from body by convection and evaporation. in order to detect body areas responsible for heat loss, surface temperatures in two species of african mole-rats were measured at different ambient air temperatures by infrared thermography. fur characteristics were also evaluated. thinner pelage of the ventrum, its moderate te ... | 2007 | 17544016 |
| chromosomal phylogeny and evolution of the african mole-rats (bathyergidae). | the subterranean african mole-rats (family bathyergidae) show considerable variation in their diploid numbers, but there is limited understanding of the events that shaped the extant karyotypes. here we investigate chromosomal evolution in specimens representative of six genera and an outgroup species, the cane rat thryonomys swinderianus, using flow-sorted painting probes isolated from the naked mole-rat, heterocephalus glaber (2n = 60). a chromosomal phylogeny based on the cladistic analysis o ... | 2008 | 18293105 |
| the visual system in subterranean african mole-rats (rodentia, bathyergidae): retina, subcortical visual nuclei and primary visual cortex. | we have studied the visual system of subterranean mole-rats of the rodent family bathyergidae, for which light and vision seem of little importance. the eye diameter varies between 3.5mm in bathyergus suillus and 1.3mm in heterocephalus glaber. the small superficial eyes have features typical of sighted animals (clear optics, well-developed pupil and well-organized retina) and appear suited for proper image formation. the retinae are rod-dominated but possess rather high cone proportions of abou ... | 2008 | 18331898 |
| social structure predicts genital morphology in african mole-rats. | african mole-rats (bathyergidae, rodentia) exhibit a wide range of social structures, from solitary to eusocial. we previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. this was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. we hypothesized that the lack of sex differences in naked mole-rats might be related to ... | 2009 | 19829697 |
| cost of digging is determined by intrinsic factors rather than by substrate quality in two subterranean rodent species. | searching for food by extensive digging is one of the most important aspects of life of subterranean rodents. we studied the effect of extrinsic (substrate quality) and intrinsic factors (sex and body mass) upon the cost of burrowing, expressed as digging metabolic rate (dmr) in two african mole-rat species (bathyergidae, rodentia) with distinct social structures. the sexually dimorphic giant mole-rat (fukomys mechowii) is a highly social species, whereas the almost monomorphic silvery mole-rat ... | 2010 | 19840810 |
| light perception in two strictly subterranean rodents: life in the dark or blue? | the african mole-rats (bathyergidae, rodentia) are strictly subterranean, congenitally microphthalmic rodents that are hardly ever exposed to environmental light. because of the lack of an overt behavioural reaction to light, they have long been considered to be blind. however, recent anatomical studies have suggested retention of basic visual capabilities. in this study, we employed behavioural tests to find out if two mole-rat species are able to discriminate between light and dark, if they ar ... | 2010 | 20676369 |
| a seasonal difference of daily energy expenditure in a free-living subterranean rodent, the silvery mole-rat (heliophobius argenteocinereus; bathyergidae). | in seasonal climatic regimes, animals have to deal with changing environmental conditions. it is reasonable to expect that seasonal changes are reflected in animal overall energetics. the relation between daily energy expenditure (dee) and seasonally variable ecological determinants has been studied in many free-living small mammals; however with inconsistent results. subterranean mammals, i.e. fossorial (burrowing) mammals which live and forage underground, live in a seasonally and diurnally th ... | 2011 | 20858551 |
| continuous dental replacement in a hyper-chisel tooth digging rodent. | contrary to their reptilian ancestors, which had numerous dental generations, mammals are known to usually develop only two generations of teeth. however, a few mammal species have acquired the ability to continuously replace their dentition by the constant addition of supernumerary teeth moving secondarily toward the front of the jaw. the resulting treadmill-like replacement is thus horizontal, and differs completely from the vertical dental succession of other mammals and their extinct relativ ... | 2011 | 21987823 |
| ear structures of the naked mole-rat, heterocephalus glaber, and its relatives (rodentia: bathyergidae). | although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, heterocephalus glaber. in this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. the ears of five other bathyergid species (bathyergus suillus, cryptomys hottentotus, fukomys micklemi, georychus capensis and heliophobius argenteocinereus) were examined for comparative purposes. the mi ... | 2016 | 27926945 |
| specific paucity of unmyelinated c-fibers in cutaneous peripheral nerves of the african naked-mole rat: comparative analysis using six species of bathyergidae. | in mammalian peripheral nerves, unmyelinated c-fibers usually outnumber myelinated a-fibers. by using transmission electron microscopy, we recently showed that the saphenous nerve of the naked mole-rat (heterocephalus glaber) has a c-fiber deficit manifested as a substantially lower c:a-fiber ratio compared with other mammals. here we determined the uniqueness of this c-fiber deficit by performing a quantitative anatomical analysis of several peripheral nerves in five further members of the bath ... | 2012 | 22528859 |
| temperature preferences of african mole-rats (family bathyergidae). | many animals are able to detect small temperature differences and show strong temperature preferences during periods of rest and activity. mammals inhabiting the subterranean ecotope can adapt their digging and foraging activity in shallow tunnels temporarily to periods with favourable ambient air and soil temperatures. moreover, subterranean mammals have the unique opportunity to select for their nests in soil depths with certain, daily and seasonally constant temperatures. our knowledge on nes ... | 2015 | 26590451 |
| magnetic compass orientation in two strictly subterranean rodents: learned or species-specific innate directional preference? | evidence for magnetoreception in mammals remains limited. magnetic compass orientation or magnetic alignment has been conclusively demonstrated in only a handful of mammalian species. the functional properties and underlying mechanisms have been most thoroughly characterized in ansell's mole-rat, fukomys anselli, which is the species of choice due to its spontaneous drive to construct nests in the southeastern sector of a circular arena using the magnetic field azimuth as the primary orientation ... | 2012 | 22855619 |
| surprisingly low risk of overheating during digging in two subterranean rodents. | capacities for and constraints of heat dissipation are considered to be important factors governing maximum intensity and duration of physical activity. subterranean mammals are endurance diggers, but because of lack of air currents in their burrows, high relative humidity and other physical constraints, the capacity of common mammalian cooling mechanisms underground is very limited. we analyzed surface and body core temperature changes after digging in soft and hard substrates in two species of ... | 2015 | 25446207 |
| dental peculiarities in the silvery mole-rat: an original model for studying the evolutionary and biological origins of continuous dental generation in mammals. | unravelling the evolutionary and developmental mechanisms that have impacted the mammalian dentition, since more than 200 ma, is an intricate issue. interestingly, a few mammal species, including the silvery mole-rat heliophobius argenteocinereus, are able to replace their dentition by the addition of supernumerary molars at the back of jaw migrating then toward the front. the aim here was to demonstrate the potential interest of further studying this rodent in order to better understand the ori ... | 2015 | 26401449 |
| do subterranean mammals use the earth's magnetic field as a heading indicator to dig straight tunnels? | subterranean rodents are able to dig long straight tunnels. keeping the course of such "runways" is important in the context of optimal foraging strategies and natal or mating dispersal. these tunnels are built in the course of a long time, and in social species, by several animals. although the ability to keep the course of digging has already been described in the 1950s, its proximate mechanism could still not be satisfactorily explained. here, we analyzed the directional orientation of 68 bur ... | 2018 | 30402349 |
| evaporative water loss in seven species of fossorial rodents: does effect of degree of fossoriality and sociality exist? | in terrestrial endotherms, evaporation is a significant mechanism of water loss in hot environments. although water is passively lost by evaporation, individuals can regulate it at different levels. inhabiting a relatively stable environment characterized by mild ambient temperature (ta) and high humidity can ensure a balanced water budget. many fossorial rodents are well adapted to live in such conditions. in this study, evaporative water loss (ewl) of fossorial rodent species with different de ... | 2020 | 32364971 |