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1.
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1. The urine compositions of the European mole Talpa europaea and of the white rat Rattus norvegicus (albino) kept on a carnivore's diet were compared. 2. The urine of moles contained bicarbonate while that of rats kept on a carnivore's diet did not. 3. Urine volume per 100 g body mass over 24 hr was significantly higher in the mole than in the rat. 4. The results of this study suggest that the mole, like other subterranean mammals on the one hand and caecal fermenters on the other, may use its kidneys as a pathway for releasing bicarbonate in its hypercapnic environment.  相似文献   

3.
Eremitalpa granti namibensis is a small, blind, subterranean insectivore endemic to the Namib desert sand dunes. Unlike most other subterranean mammals, E. g. namibensis lacks a permanent burrow system and is a surface forager. Population density and home range utilization were studied by following surface trails and capture, mark and recapture. Population density was low but stable and home range size large, a reflection of the low food availability in the Namib dune environment. No permanent nests or burrows were found while the pattern of home range utilization was nomadic but circumscribed. Home ranges overlapped with those of neighbouring animals.  相似文献   

4.
A Rich variety of anatomical and physiological specializations has enabled members of the family Talpidae (moles, shrew moles, and desmans) to exploit a diverse range of habitats: terrestrial, semi-aquatic, aquatic/fossorial, semi-fossorial, and fossorial. While numerous morphological and biochemical studies pertaining to the origin and radiation of the Talpidae have been completed, phylogenetic hypotheses remain controversial. To address this shortcoming we sequenced the mitochondrial DNA cytochrome b gene (1140bp) from 29 individuals spanning 12 talpid species. Phylogenetic trees incorporating 12 New and Old World genera (18 species; all 3 extant subfamilies) were then constructed using NJ, MP, ML, and NJ-ML (NJ with ML parameters) methods. Our results provide molecular support for a mononphyletic Talpidae, and suggest that the 12 genera are clustered into seven major clades; (1) Asiatic shrew-like moles (Uropsilus), (2) North American aquatic/fossorial moles (Condylura), (3) North American fossorial moles (Parascalops, Scalopus, and Scapanus), (4) North American semi-fossorial shrew moles (Neurotrichus), (5) Japanese semi-fossorial shrew moles (Dymecodon and Urotrichus), (6) European semi-aquatic desmans (Desmana), and (7) Eurasian fossorial moles (Euroscaptor, Mogera, and Talpa). None of these groupings comprised mole species from both continents. In fact, North American moles and shrew moles do not appear to have specific affinities with Asian moles and shrew moles, respectively. Although low bootstrap support was generally found for evolutionary nodes uniting the major talpid clades, all gene trees constructed identified fossorial North American and Eurasian mole lineages as nonmonophyletic groups, suggesting subterranean specializations arose independently at least twice during the evolution of the Talpidae. Additionally, our data set provides molecular support for a basal divergence and long independent history of Uropsilus from the main talpid line, and refutes the traditional taxonomic status and secondarily basal phylogenetic placement of the subfamily Desmaninae within the Talpidae.  相似文献   

5.
Diet and foraging behaviour of three species of burrowing huntsman spiders, Leucorchestris arenicola, L. steyni and Carparachne aureoflava , from the Namib dunes were investigated over a three-year period. These nocturnal spiders are polyphagous predators that prey on more than 97 species of insects, arachnids and reptiles. Most prey were nocturnal or crepuscular tenebrionid beetles, moths and weevils. Diet varied regionally owing to faunal differences, but was relatively constant over seasons. Although spiders occasionally captured prey greater than themselves, average prey length was about two-thirds their own length. Prey size was not strongly related to spider size. Larger spiders were both cannibals and intraguild predators. Foraging pattern of L. arenicola was variable with several nights of activity followed by one or several nights of rest. Spiders foraged within 3 m of the burrow, but occasionally pursued prey or neighbouring conspecifics further. Large prey (> 3 mm) were captured approximately every five weeks in summer and every seven weeks in winter, producing an average annual consumption of ≅ 10 prey/spider. Namib huntsmen are sit-and-wait predators within narrow territories waiting for the fortuitous arrival of prey and are thus unlikely to limit prey populations. They compensate for food shortages by cannibalism, thus restricting their own population.  相似文献   

6.
Metabolic and body temperature (Tb) responses of star-nosed moles (Condylura cristata) exposed to air temperatures ranging from 0 to 33 degrees C were investigated. The thermoneutral zone of this semi-aquatic mole extended from 24.5 to 33 degrees C, over which its basal rate of metabolism averaged 2.25 ml O2 g-1 h-1 (45.16 J g-1 h-1). This rate of metabolism is higher than predicted for terrestrial forms, and substantially higher than for other moles examined to date. Minimum thermal conductance was nearly identical to that predicted for similar-sized eutherians and may represent a compromise between the need to dissipate heat while digging and foraging in subterranean burrows, and the need to conserve heat and avoid hypothermia during exposure to cold. C. cristata precisely regulated Tb (mean +/- SE = 37.7 +/- 0.05 degrees C) over the entire range of test temperatures. Over three separate 24-h periods, Tb of a radio-implanted mole varied from 36.6 to 38.8 degrees C, and generally tracked level of activity. No obvious circadian variation in Tb and activity was apparent, although cyclic 2-4 h intervals of activity punctuated by periods of inactivity lasting 3-5 h were routinely observed. We suggest that the elevated basal metabolic rate and relatively high Tb of star-nosed moles may reflect the semi-aquatic habits of this unique talpid.  相似文献   

7.
We have investigated the relationship between spotted hyaenas in the south Namib Desert and large herbivorous prey and have summarized an updated overview of predator‐prey relationships in this resource‐limited arid environment. Over the 52‐month study, we recorded the densities (#/km−2, ±SE) of the four local large herbivorous prey species: gemsbok (1.229, ±0.50), springbok (1.352, ±0.48), ostrich (0.648, ±0.23), and greater kudu (0.343, ±0.00). A fecal analysis was performed on 146 collected spotted hyaena scats, and prey items were identified and hairs cross‐follicle analyzed to the species level. Spotted hyaena diet at the study area remained opportunistic with 240 identified prey items representing eight differing prey species being recorded, ranging from ostrich eggs to large ungulates. The Ivlev''s Electivity Index was used to determine which large herbivorous prey was most selected for. Although gemsbok had a higher representation of prey items in the sampled scats, all sampled large herbivorous prey species scored below 0 and are thus generally avoided in relation to their availability in the environment. If any prey preferences are expressed by spotted hyaena in the Namib, it can be presumed to be a nonsampled prey species. We therefore promote further detailed investigations into all other prey species present, and seasonal variations of prey densities and scat sampling, within the study environment.  相似文献   

8.
1. Laboratory and field studies of energy and water metabolism employing isotopic dilution methods examined the ability of Namib Desert moles to survive on an insect diet without drinking water. 2. Water independence is achieved through efficient renal function while low rates of energy usage and torpor are further effective in reducing overall water requirements.  相似文献   

9.
Our understanding of the effect of Pleistocene climatic changes on the biodiversity of European mammals mostly comes from phylogeographical studies of non‐subterranean mammals, whereas the influence of glaciation cycles on subterranean mammals has received little attention. The lack of data raises the question of how and to what extent the current amount and distribution of genetic variation in subterranean mammals is the result of Pleistocene range contractions/expansions. The common mole (Talpa europaea) is a strictly subterranean mammal, widespread across Europe, and represents one of the best candidates for studying the influence of Quaternary climatic oscillation on subterranean mammals. Cytochrome b sequences, as obtained from a sampling covering the majority of the distribution area, were used to evaluate whether Pleistocene climate change influenced the evolution of T. europaea and left a trace in the genetic diversity comparable to that observed in non‐subterranean small mammals. Subsequently, we investigated the occurrence of glacial refugia by comparing the results of phylogeographical analysis with species distribution modelling. We found three differentiated mitochondrial DNA lineages: two restricted to Spain and Italy and a third that was widespread across Europe. Phylogenetic inferences and the molecular clock suggest that the Spanish moles represent a highly divergent and ancient lineage, highlighting for the first time the paraphyly of T. europaea. Furthermore, our analyses suggest that the genetic break between the Italian and the European lineages predates the last glacial phase. Historical demography and spatial principal component analysis further suggest that the Last Glacial Maximum left a signature both in the Italian and in the European lineages. Genetic data combined with species distribution models support the presence of at least three putative glacial refugia in southern Europe (France, Balkan Peninsula and Black Sea) during thelast glacial maximum that likely contributed to post‐glacial recolonization of Europe. By contrast, the Italian lineage remained trapped in the Italian peninsula and, according to the pattern observed in other subterranean mammals, did not contribute to the recolonization of northern latitudes. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 495–512.  相似文献   

10.
 Using ratio-tracking data obtained at three sites, we assessed the effects of season and of neighbour avoidance on the activity and patterns of home range use by European moles (Talpa europaea). The home ranges of non-breeding male and female moles did not differ significantly in size, and averaged 2324 m2 (minimum convex polygon). Although overlap between ranges was small (an average of 12.8% of each range being shared with neighbours and an average of only 3.3% of 2×2 m grid cells were shared with an individual neighbour, ranges were not oriented to avoid neighbours. Non-breeding male/female neighbours tended to share more of their grid cells (3.9±5.7%) mean ±SD than did neighbours of the same sex (male:male 1.2±0.95%; female:female 1.1±1.3%), but there was no significant difference in overlap between any combination of sex pairings. On average, each mole spent only 0.9% of its time within 6 m of another mole, and only 3 out of 46 dyads showed evidence of being attracted to each other; there was no evidence from the simultaneous movement patterns of neighbouring moles that they avoided each other. Although moles tended to return to the same part of their range at the same time on successive days, there was also some indication of gradual changes in the spatial pattern of daily home range use. Moles had a triphasic pattern of activity, but this became tetraphasic under drought conditions. There were significant differences between sites, but not between sexes, in sleeping behaviour and activity patterns. These differences could be related to seasonal differences in soil moisture and thus probably to prey renewal rates. We conclude that in our sites, the activity patterns and movements of moles depend on the temporal and spatial dispersion of food, rather than on short-term interactions between the movements of neighbours. Received: 13 January 1996 / Accepted: 26 June 1996  相似文献   

11.
Summary The foraging behavior of the subterranean mole rat Spalax ehrenbergi (Rodentia, Spalacidae) was tested according to the framework of optimal foraging theory. We compared the frequencies of food species hoarded in storage chambers of mole rats with the frequencies of these species occurring in the vicinity of the mole rats' nest mounds during the winter and spring seasons. In addition, we examined the food composition of several summer nest mounds. Laboratory observations were conducted in order to test the foraging behavior of mole rats under simulated subterranean conditions. The mole rat is a generalist and collects a variety of food species. Out of 33 plant species that were hoarded by mole rats in the 21 studied nest mounds, 61% (n=20) were geophytes, 21% (n=7) perennial herbs, 15% (n=5) annual herbs and 3% (n=1) dwarf shrubs. The frequency of each collected species in the 16 winter and spring nest mounds is in general accordance with its frequency in the mole rat's territory. This implies that the mole rat randomly samples the food reserve of its territory without special preference or directed search for a particular species. The collection or avoidance of any food item is not dependent on the presence or absence of any other food item. We suggest that the foragin generalism of the mole rat is a product of the constraints of a subterranean niche — the necessity to hoard food as much as possible in a limited time period and the high energetic investment of tunneling to the food items.  相似文献   

12.
Decreases of respiration rates in the presence of excess sugars, substrates and non-substrates, were investigated kinetically on the cell free preparation of a Pseudomonas. The schemes of enzyme inhibition which include successive inactive complexes of one mole of enzyme and two and three moles of substrate or one mole of enzyme and one and two moles of inhibitor were shown to fit the experimental results. Water concentrations were not enough to explain the different inhibitory properties of sugars.  相似文献   

13.
The utilization of sugars present in wood hemicellulose byKlebsiella pneumoniae was investigated. Production of 2, 3-butanediol was optimal under anaerobic conditions with all sugars tested, with the exception of D-xylose which appeared to require a finite air supply for maximal diol yield. Anaerobic growth and solvent production of the organism on individual sugars revealed a similar pattern: diol production occurred generally at late exponential phase, concomitant with a culture off drop, and continued into stationary phase of growth. Solvent yields of 0.69 moles of 2, 3-butanediol and 0.69 moles of ethanol could be obtained per mole of D-glucose fermented anaerobically, while 0.45 moles of diol and 0.34 moles of ethanol were obtained per mole of xylose fermented under conditions of finite air supply.  相似文献   

14.
When microtubules are purified by polymerization and depolymerization in a buffer containing glycerol, some glycerol becomes bound to the microtubule protein and is not removable by gel filtration or by prolonged dialysis. Both 6s tubulin and larger aggregates containing tubulin and accessory proteins bind glycerol. The 6s fraction has associated with it about 5 moles of glycerol per mole of tubulin dimer; 3 moles are exchangeable upon polymerization-depolymerization and 2 moles are not. The aggregate fraction has associated with it about 22 moles of glycerol per mole of tubulin dimer; approximately 11 moles are exchangeable and 11 moles are not.  相似文献   

15.
Carolyn M.  King 《Journal of Zoology》1976,180(4):525-535
Weasels were regularly livetrapped, anaesthetized and searched for fleas over two years, in Wytham Woods, near Oxford. Eleven species of fleas were identified among 262 collected. Seven normally occur on small rodents, one on rats, two on moles and one on birds. Fleas were collected on 103 of 338 occasions when an unconscious weasel was examined; on average males carried 0·6 fleas, females 1·5 fleas, but there was no significant difference between the proportion of males and females infested. The species distribution of the fleas on weasels in Wytham suggests that they acquire their fleas mainly from the nests and runways of their prey, which they have hunted through or taken over. Important prey, e.g. birds (22% of prey items identified) with uninviting nests contributed few fleas (2%); non-prey, e.g. moles (0–4% of items) with highly desirable nests, contributed disproportionately many, including 35 fleas (15%) of two species otherwise monoxenous on moles. A similar pattern is shown by the fleas carried by stoats in New Zealand.  相似文献   

16.
1. By changing the concentrations of Mg2+ and Ca2+ ions and ATP, the Ca2+, Mg2+-dependent ATPase [EC 3.6.1.3] of SR was converted to various enzymatic states, E, MgE, MgECa, MgEATP' CaECa, and CaECap at pH 8.0 and 0 degrees (cf. Eq. 1). 2. SR vesicles were allowed to react with 0.5 mM 2,4,6-trinitrobenzenesulfonate (TBS) at pH 8.0 and 0 degrees, keeping the ATPase in one of the enzymatic states listed above. Trinitrophenyl (TNP)-protein and TNP-lipid were separated by gel-filtration, and the amounts of TNP incorporated into protein and lipid were determined. 3. In all the enzymatic states of ATPase tested, the amount of TBS bound with SR protein increased exponentially with time, and reached a maximum level 10 min after starting the reaction. On the other hand, the amount of TBS bound to lipid increased with time, and did not reach a maximum level for at least 20 min. 4. The SR ATPase activity and the amount of EP formed decreased only slightly, even when the amount of TBS bound to SR protein reached the maximum level. 5. The maximum amount of TBS bound to SR protein varied on changing the enzymatic state of SR ATPase. Namely, about 2,3,1,3, or 4, and 3 moles of TNP were incorporated per mole of SR ATPase, when SR was allowed to react with TBS in the enzymatic states MgE, MgECa, MgEATP' CaECa, and CaECap, respectively. 6. When the enzymatic state was changed from MgE to MgECa 10 min after starting the reaction with TBS, about 4 moles of TBS was bound per mole of ATPase within 10 min, while the maximum levels of TBS bound in states MgE and MgECa were about 2 and 3 moles per mole of ATPase, respectively, as mentioned above. 7; When the enzymatic state was changed from MgE to MfEATP 10 min after starting the reaction with TBS, about 3 moles of TBS was bound per mole of ATPase within 10 min, while the maximum levels of TBS bound in states MgE and MgEATP were about 2 and 1 moles per mole of ATPase, respectively, as mentioned above. 8. When the enzymatic state was changed from CaECa to CaECap 10 min after starting the reaction with TBS, about 4 moles of TBS was bound per mole of ATPase, while the maximum levels of TBS bound in states CaECa and CaECap were about 3 or 4 moles per mole of ATPase, respectively. 9. A diagrammatic model of functional movements of the ATPase molecule coupled with elementary steps in the ATPase reaction is proposed on the basis of these results.  相似文献   

17.
Allozyme variation was examined for 382 moles (Scalopus aquaticus) collected from 16 localities located within a 23 km2 area in South Carolina, U.S.A. Of 26 presumptive loci that were scored for all moles, 8 (30.8%) were observed to be polymorphic. Mean direct-count heterozygosity was 7.2%, c. 75% higher than the mean value reported for mammals. The findings of this study do not support the hypothesis that more purely subterranean species of mammals will exhibit levels of allozyme variation lower than those of above-ground species.  相似文献   

18.
Vision has long been considered purposeless in the dark underground ecotope. However, recent anatomical studies revealed an unexpected diversity of ocular and retinal features and various degrees of development of the visual system in mammals with predominantly subterranean activity, and have suggested retention of basic visual capabilities even in some strictly subterranean mammals such as the African mole‐rats. Behavioural tests assessing image‐forming vision have not yet been conducted in subterranean mammals. Here, we investigated the visual capacities in three species of the African mole‐rats, namely the giant mole‐rat Fukomys mechowii, the Mashona mole‐rat Fukomys darlingi and the silvery mole‐rat Heliophobius argenteocinereus, in the fossorial coruro Spalacopus cyanus and the inbred C57L/J mouse. The behavioural assays performed in this study revealed severe visual deficits in all three species of mole‐rats. The absence of the visual placing reflex suggested impairment of either image‐forming vision or visuomotor integration. The random choice between the shallow and the deep side of a visual cliff clearly demonstrated inability of mole‐rats to perceive depth. The nesting assay did not yield conclusive evidence regarding the capacity for visually guided spatial orientation in the only tested species, the giant mole‐rat. In contrast, both the coruro and the mouse exhibited a clear placing reaction and preferred the shallow side of the visual cliff, implying functional image‐forming vision. Thus, the behavioural data gathered in this study show that vision is seriously compromised in the strictly subterranean, congenitally microphthalmic African mole‐rats but efficient (i.e. comparable to that of surface‐dwelling rodents) in a species with regular surface activity, the coruro.  相似文献   

19.
Measurement of the volume change by a rapid density method upon sequential addition of calcium ion to calmodulin showed relatively large, nonuniform increases for the first 4 moles Ca2+ per mole calmodulin. Substantially larger volume increases (approximately 15 ml/mol protein) were observed upon addition of the second and fourth moles Ca2+ relative to the first and third moles added per mole calmodulin. A total volume increase of approximately 170 ml/mol protein attended the addition of 4 moles Ca2+, as expected for multidentate carboxylate coordination to metal ion. Marginal changes in volume were observed upon further additions, the data showing a remarkably sharp transition after [Ca2+]/[calmodulin] = 4. The results are consistent with an ordered binding of Ca2+ in which pair-wise additions produce similar volume changes; the volume change behavior, however, does not indicate an absence of distinct conformational states for a Ca2+(1)-calmodulin and a Ca2+(3)-calmodulin complex as has been proposed on the basis of 1H-NMR evidences.  相似文献   

20.
OBJECTIVE--To validate self screening by patients of high mole counts, assess the within family association of sun protection behaviour and mole counts, and estimate prevalence of risk factors for melanoma. SETTING AND SUBJECTS--Systematic sample of families from a single affluent general practice population in Wessex. DESIGN--Subjects completed a questionnaire about risk factors for melanoma and counted their moles. Subsequently a mole count was done by a general practitioner trained at dermatology clinics. MAIN OUTCOME MEASURES--Validation of self counts by observer''s count. Within family association of sun protection behaviour and mole counts; self reported risk factors. RESULTS--199/237 subjects (84%) returned the questionnaire; 212/237 (89%) were examined. High counts by patients on the front of the trunk (> 7 moles of > or = 2 mm) were reasonably sensitive (79%), predictive (75%), and specific (97%) of the observer''s mole counts (kappa = 0.74), unlike arm or total body counts. Sun protection behaviour correlated between individuals and other family members (Spearman''s coefficient r = 0.50, P < 0.01). In the past three months 15/114 adults (13.2%, 95% confidence interval 7.0% to 19.4%) reported any change in a mole and 6/114 (5.3%, 2.0% to 11.1%) "major" changes; 6/109 adults (5.5%, 2.1% to 11.6%) had both high mole counts and freckling. CONCLUSIONS--Asking patients to count trunk moles could be a feasible way of identifying patients at high risk of melanoma. Concentrating on reported major changes in moles should avoid considerable workload in general practice. The generalisability of these findings and the adverse effects, net benefit in earlier diagnosis and prevention, and workload implications of such self screening need further research.  相似文献   

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