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1.
Geographic and nongeographic variation in morphology was examined in Thomomys townsendii . A univariate analysis of external and cranial characters from a large population sample (66 adults; fusion of cranial sutures used as aging criteria) was used to assess variation among three adult age classes and between sexes. Only minor variation is apparent among age classes; however, sexual dimorphism is pronounced. Univariate and multivariate techniques were used to analyze external and cranial measurements and pelage characters for adults throughout the species range. These analyses show little to support the seven subspecific designations recognized by Davis (1937). The general pattern is one of homogeneity throughout the range of Thomomys townsendii . With the possible exception of T. t. nevadensis samples, current subspecies are not defined as morphological units. In fact, differentiation is found among populations within some subspecies. The most apparent pattern seen in these analyses is the divergence between the Humboldt River (including Honey Lake Valley samples) and Snake River systems. These results will be considered with those of a companion paper on the genetic variation in this species to more adequately assess the patterns of differentiation in Thomomys townsendii .  相似文献   

2.
Distribution and habitat selection of hibernating bats at the Idaho National Engineering Laboratory (INEL) and adjacent area are reported. Exploration of over 30 lava-tube caves revealed that two species, Myotis leibii and Plecotus townsendii, hibernate in the upper Snake River Plain. Five species, M. lucifugus, M. evotis, Eptesicus fuscus, Lasionycteris noctivagans, and Lasiurus cinereus are considered migratory. Myotis leibii and P. townsendii hibernate throughout much of the area, occasionally in mixed-species groups. Myotis leibii uses the dark and protected regions of the cave, usually wedged into tiny pockets and crevices near or at the highest portion of the ceiling. Individuals of P. townsendii may be found at any height or depth in the cave. Temperature appears to be the primary limiting factor in habitat selection. Myotis leibii was found in significantly cooler air temperatures than P. townsendii . Neither species tolerated continuous temperatures below 1.5 C. Relative humidity does not seem to be a significant factor in the distribution or habitat selection of the two species in lava-tube caves.  相似文献   

3.
Two subspecies of the big brown bat ( Eptesicus fuscus ) are reported to occur in Nebraska. The eastern race, E. f. fuscus , is reportedly bigger and darker than its western counterpart E. f. pallidus . Where these 2 subspecies come in contact is the subject of debate. We used external, cranial, and colorimetric data to investigate geographic variation among populations of E. fuscus in Nebraska to determine the location of the zone of contact between E. f. fuscus and E. f. pallidus . We discovered significant variation in external, cranial, and colorimetric data, suggesting that E. fuscus is represented by 2 subspecies in Nebraska. Our results showed that E. f. pallidus is smaller, possesses lighter pelage, and is restricted to the northern and western parts of Nebraska, whereas E. f. fuscus is larger, possesses darker pelage, and occurs in southern and southeastern parts of the state. Populations located between these regions represent intergrades of the 2 subspecies. We suggest that the subspecific boundary represents a broad zone of integration running in a northeast to southwest direction and may reflect the position of temperature and precipitation clines.  相似文献   

4.
Spermophilus brunneus is restricted to a 90 × 125-km area of west central Idaho, with two distinct (northern and southern) groups of populations within this limited range. Morphological differences in pelage length and coloration, external and cranial measurements, and bacula suggest that these groups are either very distinct subspecies or species. We used starch-gel electrophoresis to estimate the amount of genetic differentiation accompanying these morphological differences by assaying genetic variation at 31 loci in the two geographic groups. Fifteen loci were polymorphic (13 in the northern group, 12 in the southern), and mean heterozygosity (H) was high (12.3% northern and 10.8% southern). Nei's genetic distance (0.057) is in the range usually associated with subspecific differences. However, Jaccard's association coefficient (0.893) is about the same as that found between several ground squirrel taxa currently recognized as species. The high levels of heterozygosity suggest that S. brunneus is a neoendemic rather than a paleoendemic species.  相似文献   

5.
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6.
We captured 299 individuals of 11 bat species in mist-nets at 18 water sources in west central Nevada from June through August 1994. Myotis ciliolubrum, Pipistrellus hesperus, M. californicus , and Corynorhinus townsendii were the most common species captured. These species are apparently broadly distributed throughout west central Nevada, occurring in a variety of habitat types. We captured Euderma maculatum at 2 localities. These represent the 1st known records of this species in Esmeralda County, Nevada. Mine adits were surveyed for hibernating bats from December 1994 through February 1995. We determined the presence of 3 hibernating species: C. townsendii, M. ciliolabrum and P. hesperus . Bats were present in 19 of 70 mines (27%) we surveyed at elevations ranging from 1500 m to 2460 m. C. townsendii was the most common species encountered. Our study provides some much-needed baseline data on bat distribution and use of mines for hibernacula in west central Nevada.  相似文献   

7.
We examined morphology of 4 sucker species (Catostomidae) from Klamath and Rogue River basins, Oregon and California. Different pairs of these species have been suspected of hybridizing, and field biologists have experienced difficulty identifying individuals in some areas. The suite of morphological characters used for initial identification was poorly supported by other morphometric characters but well supported by meristic characters, especially when analyses were restricted geographically. In some species sexual dimorphism was evident, with males having longer pectoral fins and females having longer pre-anal counts and measurements. Each species showed geographic differentiation, either between the Lost River subbasin and other Klamath subbasins or between Klamath and Rogue basins. Classification was most difficult for Catostomus snyderi , which was frequently misclassified as all other species, but especially as Chasmistes brevirostris . Despite this, the 2 species are ecologically segregated in the upper subbasins with lake-spawning Ch. brevirostris spatially segregated and river-spawning Ch. brevirostris temporally segregated from river-spawning C. snyderi . We discuss the possibility that a large-headed, thin-lipped species has become extinct in Upper Klamath Lake and alternatively suggest that the form could represent an ecophenotype of Ch. brevirostris that is no longer produced in hypereutrophic Upper Klamath Lake.  相似文献   

8.
A study aimed at testing the contested validity of the subspecies Laudakia stellio daani yielded novel insights into the essence of subspecies. We examined morphologically museum specimens from Greece, Aegean islands, and Anatolia (n?=?118; not all could be used in all analyses). Beyond the conventional mensural, meristic and qualitative characters we quantified 14 coloration characters, thus totalling 34 characters (including sex). Biometry was statistically analysed within and between the two geographically defined presumed subspecies, L. s. daani and L. s. stellio. Excluding or including broken‐tailed specimens changed the outcome of tests. Significant minor directional asymmetry occurred in one of four character‐taxon combinations. Phenetic cluster analysis poorly separated the two presumed subspecies when all characters, including those with discordant variation, were included; after selection of characters, the separation improved. Some biometric characters distinguish the two presumed subspecies, confirming their validity. The associations of significant inter‐character correlations differed between the two subspecies. Additionally, the two differed in parameters reflecting selection pressures and social structure: L. s. stellio is more colourful than L. s. daani; its sexual dimorphism is mainly chromatic, versus mensural in L. s. daani; and its population seems to include many males with underdeveloped callous scales, presumably socially subordinate, versus very few in L. s. daani.  相似文献   

9.
10.
External morphological variation in the Lopidea nigridia "complex" of western North America was examined using principal component analysis and showed continuous variation among populations in most characters. External morphology did not parallel paramere structure and did not substantiate previously recognized species. There was little correlation between dorsal coloration and paramere structure. Cluster analysis (UPGMA) using paramere and color characters failed to group populations coded as the same species and also failed to group all specimens of any one population. The variation in structure of the parameres and vesicae among populations of the nigridia complex was no greater than the interpopulational variation of these structures structures in the congeneric species marginata Uhler. Lopidea nigridia Uhler is treated as a polytypic species comprising three subspecies: Lopidea nigridia nigridia Uhler, a fuscous-white form from the sagebrush steppe of the Great Basin and the chaparral of southern California; Lopidea nigridia serica Knight, a solid red form from the eastern slopes of the Rocky Mountains from Alberta to Colorado and east across the Northern Great Plains to southern Manitoba; Lopidea nigridia aculeata Van Duzee, a polymorphic form varying from solid red to fuscous red and white from the Cascade Mountains and eastern slopes of the coastal ranges of British Columbia, Washington, and Oregon, the Blue and Wallawa mountains of Oregon and Washington, and throughout the Coastal and Sierra Nevada ranges of California. The following new synonymies are created: Lopidea nigridia Uhler -- Lopidea raineri Knight, Lopidea scullent Knight, Lopidea rolfsi Knight, and Lopidea wilcoxi Knight; Lopidea nigridia aculeata Van Duzee -- Lopidea nigridia hirta Van Duzee, Lopidea usingeri Van Duzee, Lopidea discreta Van Duzee, Lopidea fallax Knight, Lopidea Yakima Knight, Lopidea audeni Knight, Lopidea eriogoni Knight, Lopidea calcaria Knight, Lopidea chamberlini Knight, Lopidea angustata Knight, Lopidea rubrofusca Knight, and Lopidea flavicostata Knight and Schaffner; Lopidea nigridia serica Knight -- Lopidea medleri Akingbohungbe.  相似文献   

11.
12.
Over 1,000 herbarium specimens including 24 type specimens were examined in an attempt to achieve a clearer understanding of the Phlox longifolia complex. Four variables were measured for each specimen and the data were statistically analyzed by discriminant analysis. Using a previously published system of classification for the complex, approximately 73 percent of the measured variation among the specimens was accounted for by that system. The clustering patterns produced in this first analysis indicated that a more conservative approach would be advisable. The formulation and subsequent application of a modified system produced a grouping of specimens that accounted for 95 percent of the measured variation for the four morphological characters considered. From four species and seven subspecies previously recognized, one species with five varieties is proposed. The typification of Phlox longifolia Nutt. and other related taxa is resolved.     相似文献   

13.
ABSTRACT

Pseudoscorpiones is a mesodiverse order of Arachnida, with more than 3600 described species in the world. Species delimitation is sometimes difficult due to the high variability of some characters, difficulty in finding informative and useful characters for species differentiation and the subjectivity of individual specialists. The aim of this work is to explore and to evaluate the role of morphometric characters in species delimitation within the genus Apolpium (Olpiidae). Measurements of 17 structures of 57 individuals were taken and their length/width ratios calculated. Cluster analyses, principal components analyses, discriminant function analyses and non-metric multidimensional scaling were carried out. The results showed low resolution for the number of species currently recognised in the genus. These results highlight the importance of looking for other morphological characters, and also for a more rigorous assessment of previously used characters for defining species.  相似文献   

14.
《Journal of Natural History》2012,46(41-42):2487-2500
Morphological characters and partial cytochrome oxidase (COI) DNA sequences were used to investigate intra- and interpopulation differences among three Cretan brackish-water populations of Heleobia maltzani snails. The morphology of male and female reproductive organs of H. maltzani did not differ within studied populations or in comparison with closely related species. In contrast, analysis of shell morphology revealed substantial variation not supported by the genetic data. Genetics results showed surprisingly low differentiation between all Cretan populations and also mainland populations of Heleobia. They also showed that H. maltzani is conspecific with four other European species of Heleobia, thus implying that there is only one species of brackish-water Heleobia in Europe. Such a low level of genotypic differentiation is unusual for typical island species and is most probably the consequence of recent colonization of Crete. Possible scenarios of such processes are discussed.  相似文献   

15.
Propomacrus cypriacus a saproxylic beetle endemic to Cyprus, was described as a species distinct from P. bimucronatus on the basis of a few morphological characters and has been evaluated as Critically Endangered by IUCN, as it depends on veteran trees and has a restricted distribution. Herein we explored the distribution, ecology, morphology and genetic variation of the populations from Cyprus, and we attempted a phylogenetic analysis including related species based on two mitochondrial and one nuclear DNA markers. We also used published mtDNA divergence rates to date cladogenetic events. Despite extensive sampling, we found only a small number of individuals, adding a few additional localities to the known distribution of the species, and we identified two more host species to those previously reported. Morphological examination showed that only the form of male protibiae differs consistently in Cyprus populations compared to those of P. bimucronatus from Turkey and the Lebanon. Nevertheless, genetic analyses do not support a distinct species status for populations from Cyprus, which should instead be considered as a subspecies of P. bimucronatus. Morphological and ecological data further support this conclusion. Cyprus populations have diverged from nearby continental ones in mid to late Pleistocene.  相似文献   

16.
We investigated ecology of flannelmouth sucker ( Catostomus latipinnis ) from 1992 to 1997 in the 26-km Lee's Ferry reach of the Colorado River immediately below Glen Canyon Dam, Arizona. We captured by electrofishing a total of 212 fish and recaptured 52 previously tagged by others. Flannelmouth sucker were captured throughout the tailwater but tended to aggregate about 5 km of the dam, possibly reflecting blockage of historic migration routes. Catch per hour of electrofishing did not differ among years but was greater from November to February than other periods, suggesting seasonal movements of flannelmouth sucker into the tailwater: Mean lengths and weights of fish did not differ among years or seasons. Length frequency analyses also indicated there were no significantly yearly trends in proportion of catch within size classes of fish. Mean condition differed only among seasons and was greatest in February, lowest in August, coinciding respectively with pre- and post-spawning periods of flannelmouth sucker in tributary just down from Lee's Ferry. Recaptured fish migrated from initial tagging locations 1.4-23.1 km downstream from Lee's Ferry. Fifty-nine percent of recaptured fish with known initial tagging locations increased in length, and fish tagged initially as subadults or adults, respectively, grew an average of 45.9 mm and 5.5 mm per year.  相似文献   

17.
18.
19.
The current status of Mertensia oblongifolia (Nutt.) G. Don and its allied taxa is surveyed. On the bases of continuously coherent morphological characters and/or regionally correlated variations, more than 30 taxa, including species, subspecies, varieties, and 1 forma, previously considered different from M. oblongifolia , are now placed under synonymy of this species. Those taxa currently known as M. fusiformis Greene, M. bakeri Greene, and M. bakeri var. osterhoutii Williams are among the new synonyms. Typification, taxonomy, and morphological problems of M. oblongifolia are discussed.  相似文献   

20.
《Journal of Natural History》2012,46(6):1165-1189
A cladistic analysis of the 6 species of Euxanthe is given utilizing 15 characters, and the species' geographical distributions discussed in relation to the proposed cladogram. The division of the genus into two subgenera by past revisers is seen to be justified. The relatively rapid anagenesis of E. madagascariensis is considered, and mimicry in the group discussed. A key to the 15 species and subspecies taxa is given, and each is revised. Notes on the biology of the species and subspecies are included, 7 lectotypes are designated and 2 new synonyms established.  相似文献   

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