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1.
Comparative histological studies of the integuments of the Dorcas gazelle, jerboa and camel have revealed the presence of tubular sweat glands in the skin of the Dorcas gazelle and the camel but not in the jerboa.
Hairs occur in groups in the skin of jerboa and camel but occur singly in the Dorcas gazelle where they are of two types; short under hairs and long covering hairs. Each hair follicle is associated with a sebaceous gland. Both the unkeratinized epidermis and its horny layer are comparatively thin in the jerboa and gazelle, and in dry air this may permit greater loss of water by transpiration than in the camel which has a comparatively thick epidermis.  相似文献   

2.
The mountain gazelle (Gazella gazelle), Dorcas gazelle (Gazella Dorcas) and acacia gazelle (Gazella arabica acacia) were historically abundant in the southern Levant, and more specifically in Israel. Anthropogenic and natural changes have caused a rapid decline in gazelle populations, raising concerns about their conservation status and future survival. The genetic profile of 111 wild gazelles from Israel was determined based on three regions of mitochondrial DNA (control region, Cytochrome b and 12S ribosomal RNA) and nine nuclear microsatellite markers. Genetic analysis of the mountain gazelle population, the largest known population of this rare species, revealed adequate diversity levels and gene flow between subpopulations. Nevertheless, ongoing habitat degradation and other human effects, such as poaching, suggest the need for drastic measures to prevent species extinction. Dorcas gazelles in Israel displayed inbreeding within subpopulations while still maintaining considerable genetic diversity overall. This stable population, represented by a distinctive genetic profile, is fragmented and isolated from its relatives in neighboring localities. Based on the genetic profile of a newly sampled subpopulation in Israel, we provide an alternative hypothesis for the historic dispersal of Dorcas gazelle, from the Southern Levant to northern Africa. The small acacia gazelle population was closest to gazelles from the Farasan Islands of Saudi Arabia, based on mitochondrial markers. The two populations did not share haplotypes, suggesting that these two populations may be the last remnant wild gazelles of this species worldwide. Only a dozen acacia gazelles survive in Israel, and urgent steps are needed to ensure the survival of this genetically distinctive lineage. The genetic assessments of our study recognize new conservation priorities for each gazelle species in the Southern Levant.  相似文献   

3.
C. R. Thouless    K. Al  Bassri 《Journal of Zoology》1991,223(1):151-159
The taxonomy of Arabian gazelles has been confused by single specimen collected from the Farasan Islands in the Red Sea in the 1820s. There is still population of gazelles on the islands. They form distinct taxon most closely related to the mountain gazelle Gazella gaiella , which is characterized by small size, grey-brown colouring, very short horns in the female and rounded upper tooth-row in the male. This gazelle bears no resemblance to the type specimen of G. arabica , said to come from the Farasan Islands. In this paper the Farasan gazelle is described as Gazella gazella Jarasani n. ssp.  相似文献   

4.
动物集群的群体行为决策是营集群生活的动物调节其群体活动、而获得集群生活收益的重要手段。受动物自身行为和需求的影响,动物集群的群体决策有不同的外在表现形式和过程。本研究以青海湖湖东地区的普氏原羚种群为对象,于2010 年3 月至2012 年3 月对普氏原羚集群的群体决策过程进行了观察和记录,并对所得数据采用非参数检验方法进行统计与分析,分析结果表明:1. 普氏原羚集群的群体决策类型为不完全民主型,需要有一定比例的个体共同参与群体决策过程才能达成群体决策,而参与群体决策的个体比例随群体规模的增加而降低;2.参与决策的个体因性别不同而有不同的表现,且在决策过程所需时间上存在差异,这可能是导致普氏原羚产生同性聚群现象的原因之一。这是在野外直接对大型有蹄类动物集群的群体决策过程进行的为数不多的研究,还需要更多的野外研究来探究不同类型动物群体决策过程及其与同性聚群产生机理之间的关系。  相似文献   

5.
Z. Li  & Z. Jiang 《Journal of Zoology》2008,274(4):327-331
Tibetan gazelle Procapra picticaudata , a threatened endemic species on the Qinghai-Tibet Plateau, is a sexually dimorphic ungulate. Males are larger than females and both sexes live in different groups, except during the rutting season. In order to test the activity budget hypothesis, which was proposed to explain social segregation in ungulates, we studied the activity budget of male and female Tibetan gazelles during the summers of 2005 and 2006. The activity budget hypothesis predicts that females spend more time feeding and group members synchronize their activities more in the same-sex groups than in the mixed-sex groups. We found that females and males of Tibetan gazelle had different activity budgets; females spent significantly longer time feeding and comparably less time on other activities. Activity synchronization indexes between female groups and male groups were similar (female groups: 0.81±0.17, male groups: 0.80±0.19), whereas both of them were significantly higher than that of mixed-sex groups (0.58±0.29). These results suggest that although sexual segregation might be caused by multiple mechanisms, the activity budget hypothesis about sexual segregation is supported by our studies of Tibetan gazelle on the Qinghai-Tibet Plateau.  相似文献   

6.
Two karyotypes within the species Hemideina crassidens are described, 2n = 15 (XO) and 2n = 19 (XO). These two karyotypes have a NF of 28. The 19-karyotype was found exclusively in the southern part of the species range and the 15-karyotype was found in the north. The differences between the two karyotypes are interpreted as arising from two Robertsonian translocations (fission/fusion). Laboratory matings between weta with the two karyotypes produced viable offspring. During meiosis in F1 intraspecific hybrids metacentric and acrocentric autosomes aligned to form two trivalents, confirming homologies predicted by Robertsonian translocations. The subspecies H. c. crassicruris, (confined to Stephens Island) was found to be polymorphic for a metacentric B chromosome. An unusual association of sex and presence of B chromosome was observed in this island population with Bs found only in male weta.  相似文献   

7.
Mountain gazelle Gazella gazella in Saudi Arabia are listed as 'vulnerable' by the IUCN. At present, the species' survival is secured by extensive captive-breeding programmes and reintroductions into protected areas. Two reintroduction attempts (Ibex Reserve and Uruq Bani Ma'Arid protected areas) in Saudi Arabia have been undertaken in the past two decades. Post-monitoring of released individuals is essential for the success of such reintroduction programmes; however, cryptic species like mountain gazelles are extremely difficult to observe directly. As radio-tracking is a cost-intensive and invasive post-monitoring technique, we asked: how can reintroduced or remnant pockets of natural gazelle populations be monitored indirectly ? Here, we propose the use of latrine mapping as an effective, cost-efficient and non-invasive tool to survey the social organization of reintroduced mountain gazelles as an indicator for repatriation success. In this study, we used released radio-collared animals to characterize the spatial distribution of latrines within female group home ranges. Distance to the next latrine, latrine size, as well as numbers of fresh faecal pellet groups per latrine or presence of urination marks were used as dependent variables for step-wise backward multiple regressions and were correlated with various ecological factors. Most dependent variables were correlated with distance or direction from the nearest tree, but not indicative of home-range cores. Only latrine densities were distinctly higher in core areas of female group home ranges, and no pattern of peripheral marking was detected. Hence, latrine density is a good indicator of home-range use in female group home ranges. Mapping latrines and determining latrine densities are therefore the methods of choice to survey mountain gazelle populations.  相似文献   

8.
以往研究表明受发情交配行为制约,一些雄性反刍动物在发情期食物摄入量明显降低。已有两个相关假说解释该现象:能量摄入最大化假说和能量保存假说。作者于2009 ~ 2010 年在卡拉麦里山有蹄类自然保护区研究了雄性鹅喉羚不同发情阶段的时间分配。结果表明雄羚发情期采食时间比例明显下降(37. 9% ),低于发情前期(63. 6% )和发情后期(65. 8% );发情期卧息时间比例(6. 0% )与发情后期相近(5. 4% ),明显低于发情前期(23.2% );发情前期至发情后期采食卧息时间比(分别为2. 7、6. 3、12. 1)显著增加;发情期雄羚站立和移动时间比例明显升高,采食行为时间占非发情行为时间主要部分(86. 4% ),且采食行为与发情行为显著相关。相比之下,雌羚不同发情阶段采食行为时间分配比例相似。总之,除必需投入的发情行为外,发情期雄羚最大化其能量摄入;发情行为的投入是导致发情期雄羚食物摄入量下降的主导因子,雄性能量摄入最大化假说更好地解释了发情期鹅喉羚所采取的能量策略。  相似文献   

9.
Dorcas gazelles are believed to use middens to mark their territories and transmit information. Given the commitment to maintaining a midden, it is believed that middens are not placed randomly. We examined how the habitat (tree height and maximum canopy) and anthropogenic disturbance (camel and human presence) influenced the selection of midden sites by Dorcas gazelles in South Sinai, Egypt. Our results showed that Dorcas gazelles did not place middens at larger trees, while favoring relatively smaller trees and shrubs where the anthropogenic disturbance and perceived hunting risk are less. Our results, in light of the previous findings, suggest that selection of midden sites is species context‐dependent behavior. In areas with less anthropogenic disturbance and hunting, Dorcas gazelles have been shown to select the largest trees of the same species as midden sites. In contract, in our study site with high anthropogenic disturbance and no protection from hunting, gazelles did not utilize the presumably optimum landmarks for midden sites. Our study showed that Dorcas gazelles instead utilized smaller trees and some shrubs that are less conspicuous and presumably less effective as advertisement sites, but safer.  相似文献   

10.
几种鼢鼠染色体组型和血清LDH同工酶电泳的比较研究   总被引:3,自引:0,他引:3  
本文报道了中华鼢鼠指名亚种、甘肃亚种、四川亚种、罗氏鼢鼠的染色体组型和LDH同工酶电泳。发现中华鼢鼠3个亚种染色体数2n=60,罗氏鼢鼠2n=58;中华鼢鼠指名亚种和甘肃亚种LDH同工酶酶谱带数为3条,而中华鼢鼠四川亚种和罗氏鼢鼠为2条。同时,对分类学上争论的问题进行了讨论。  相似文献   

11.
Unsporulated oocysts were detected in the feces of an Arabian red fox (Vulpes vulpes arabica) between 6 and 8 days after it had been fed meat from Arabian mountain gazelles (Gazella gazella) known to contain sarcocysts. No oocysts were discovered in the feces of other experimental cubs, although sporocysts of Sarcocystis spp. were passed subsequently by all cubs that were fed gazelle meat, including those fed with reem (G. subgutturosa marica). The oocysts sporulated in 3 days at room temperature (25 +/- 2 C); they were 10.9 +/- 1.4 x 10.1 +/- 1.3 microm, with 2 sporocysts measuring 6.0 +/- 0.6 x 4.7 +/- 0.8 microm, each with 4 sporozoites. Sporulated oocysts were identified as those of Hammondia heydorni using molecular and standard morphometric techniques. Sequence differences between 2 fox and 3 dog isolates of H. heydorni were detected and allowed differentiation between the 2 populations of the organism. The involvement of Neospora caninum was excluded using molecular methods. The Arabian red fox and the Arabian mountain gazelle in Saudi Arabia are new, definitive and intermediate hosts for H. heydorni.  相似文献   

12.
Food preferences of the sand gazelle (Gazella marica) from the Mahazat as-Sayd Protected Area in Saudi Arabia were evaluated using focal animal sampling in conjunction with an eco-morphological method examining two parameters of tooth wear, i.e., occlusal relief and cusp shape. Observations of live, free-ranging animals (n = 53) showed that sand gazelles generally consumed more grass (58.4%) than browse (41.6%). However, during the dry season, gazelles spent significantly more time browsing (51.0%) and less time grazing (49.0%) than under wet conditions (browsing: 17.6%; grazing: 82.4%). Thus, consistent with predictions, sand gazelles are intermediate feeders but shift towards browsing when grass is scarce. The mesowear signature of the sand gazelle is consistent with a grazing signal in other ruminants. In other words, the browse component of the diets of live animals was not reflected in the tooth wear. This could have occurred because browse is less abrasive than grass, but more likely because all food types are heavily abrasive in this dusty habitat. We conclude that the sand gazelle population in Mahazat as-Sayd encounters a highly abrasive diet, which has implications for their ability to meet nutritional demands.  相似文献   

13.
Ryukyu spiny rats (genus Tokudaia), which are endemic to the central part of the Nansei Shoto archipelago in Japan, have unique karyotypes with odd numbers of chromosomes and no cytologically recognizable Y chromosome. The chromosome numbers of Tokudaia osimensis from Amamioshima and of Tokudaia sp. from Tokunoshima are 2n = 25 and 2n = 45, respectively, with a putative single X chromosome. The mouse X probe hybridized to the unpaired X chromosome, except for the distal part of the short arm in a female specimen of T. osimensis and in one male and one female of Tokudaia sp. Fluorescence in situ hybridization with the Tspy (testis-specific protein, Y-encoded) gene from both male and female cells of Tokudaia sp. by PCR localized Tspy to the distal part of the long arm of the X chromosome. Another Y-related gene, Zfy, from Tokudaia sp. was also localized to the same region in both species. Although the Sry gene is absent in this species, the present results suggest that the Y-chromosome segment carrying functional Y-linked genes, such as Tspy and Zfy, is translocated onto the distal part of the long arm of the X chromosome.  相似文献   

14.
Vicia sativa L. s. l. is presented as a variable complex consisting of 7 subspecies, including wild types, weedy races and cultivated derivatives. The group is characterized by: (a) Decreasing aneuploid (dysploid) chromosome series (2n = 14 12 10,); (b) wide variation in karyotypes; (c) pronounced weediness and colonization of disturbed habitats; (d) cohabitation of several forms; (e) intergradations between the main morphological types; (f) predominance of self-pollination; (g) lack of full sterility between the main chromosome types. Plants with different chromosome numbers or different karyotypes are loosely interconnected by occasional hybridization, particularly in disturbed habitats. Colonization appears to be associated with reticulate evolution and the recombination of previously separated gene pools. The wide karyotypic polymorphism characteristic for this complex is interpreted as a result of such relatively recent processes.  相似文献   

15.
双花木属和壳菜果属(金缕梅科)的核型研究   总被引:2,自引:1,他引:1  
本文对金缕梅科Hamamelidaceae双花木属Disanthus Maxim.的长柄双花木D.cercidifolius subsp.longipes和单种属壳菜果属Mytilaria Lec.首次进行了染色体计数和核型分析。结果表明:长柄双花木与产自日本的双花木D. cercidifolius subsp.cercidifolius的体细胞染色体数目一致,均为2n=16,前者无“st”或“t”染色体,表明该亚种可能比较原始;壳菜果Mytilaria laosensis Lec.的染色体数目为2n=26,x=13。前人报道的金缕梅科染色体基数为x=8和x=12,因此x=13可能是金缕梅科的一个新染色体基数。联系该属的形态特征及其与马蹄荷属Exbucklandia R.W.Brown的关系,作者支持将壳菜果属处理为独立的亚科,即壳菜果亚科Mytilarioideae。  相似文献   

16.
The Tibetan gazelle (Procapra picticaudata) is a threatened species and distributed on the Qinghai-Tibet Plateau of China (Qinghai Province, Tibet Autonomous Region and the adjacent Gansu Province, Sichuan Province, and Xinjiang Uigur Autonomous Region). Small peripheral populations of Tibetan gazelle were once found in northern Sikkim and Ladakh, but now these are close to extinction. To describe the evolutionary history and to assess the genetic diversity within this monotypic species and population structure among different geographic locations in China, we sequenced mitochondrial DNA from the control region (CR) and cytochrome (cyt) b gene for 46 individuals from 12 geographic localities in Qinghai, Tibet, Xinjiang, Gansu, and Sichuan. A total of 25 CR haplotypes and 16 cyt b haplotypes were identified from these gazelle samples. CR haplotype diversity (0.98+/-0.01) and nucleotide diversity (0.08+/-0.009) were both high. Phylogenetic trees indicate that the Tibetan gazelle in China can be divided into three main clades: Tibet, Sichuan (SCH) and Qinghai-Arjin Shan-Kekexili (QH-ARJ-KKXL). Analysis of molecular variance (AMOVA) and network analysis consistently support this geographic structure in both datasets. Significant differentiation between populations argues for the presence of management units (MUs). Such differentiation may reflect a geographic separation resulting from the uplift of the Qinghai-Tibet Plateau during the Late Pliocene and Pleistocene. Mismatch distribution analysis implies that Tibetan gazelle has undergone complex population changes. We suggest that the present population structure has resulted from habitat fragmentation during the recent glacial period on the Qinghai-Tibet Plateau and population expansion from glacial refugia after the glacial period. It is likely that the present populations of Tibetan gazelle exhibit a pattern reminiscent of several bottlenecks and expansions in the recent past.  相似文献   

17.
In the red howler monkey, Alouatta seniculus stramineus (2n = 47, 48, or 49), variations in diploid chromosome number are due to different numbers of microchromosomes. Males exhibit a Y;autosome translocation involving the short arm of an individual biarmed autosome. Consequently, the sex-chromosome constitution in the male is X1X2Y1Y2, with X1 representing the original X chromosome, X2 the biarmed autosome (No. 7), Y1 the Y;7p translocation product, and Y2 the acrocentric homolog of 7q. In the first meiotic division, a quadrivalent with a chain configuration can be observed in spermatocytes. Females have an X1X1X2X2 sex-chromosome constitution. Chromosome heteromorphisms were observed in pair 13, due to a pericentric inversion, and pair 19, due to the presence of constitutive heterochromatin. Microchromosomes, which varied in number between individuals, were also heterochromatic. NOR-staining was observed at two separate sites on a single chromosome pair (No. 10). A comparison of A.s. stramineus with A.s. macconnelli shows that these two subspecies have identical diploid chromosome numbers (47, 48, or 49), again due to a varying number of microchromosomes, and that they share a similar sex-chromosome constitution. Their karyotypes, however, are not identical, but can be derived from each other by a reciprocal translocation. Further comparisons with other A. seniculus subspecies reported in the literature indicate that this taxon is not karyologically uniform and that substantial chromosome shuffling has occurred between populations that have been considered to be subspecies by taxonomic criteria based on their morphometric attributes.  相似文献   

18.
普氏原羚的分布和种群数量调查   总被引:9,自引:1,他引:8  
2003 年8 ~9 月,对青海省境内普氏原羚的分布和种群数量进行了专项调查。调查结果表明,普氏原羚现存7 个种群,累计数量为602 只;其中塔勒旋果种群属首次报道。与以往报道相比,目前元者和鸟岛种群数量呈下降趋势;海晏—刚察种群数量增长明显;湖东—克图种群数量有所回升,但仍没有达到20 世纪80 年代中期时的种群数量。普氏原羚种群数量变化与栖息地质量及人为干扰程度有密切相关。本次调查显示,普氏原羚现存栖息地呈不连续的间断分布,随着区域经济开发力度的加大,其栖息地在不断缩减、生存环境质量仍在继续恶化。  相似文献   

19.
大麻染色体行为分析   总被引:6,自引:1,他引:5  
以大麻不同性别的植株为材料,常规压片法观察细胞染色体行为规律。核型分析结果表明:大麻雌雄株的体细胞染色体数目均为2n=20,核型公式分别为雌株2n=2x=20=18m 2sm,雄株2n=2x=20=18m 2sm(1SAT)。雌株体细胞中有2条X染色体,而雄株只有一条X染色体和一条具有大随体的Y染色体。雌雄株核型均为2A型,为较对称核型。这一结果可为进一步研究大麻性别的分化机制提供细胞遗传学理论依据。  相似文献   

20.
国产磨芋属的染色体核型报道(Ⅱ)   总被引:4,自引:0,他引:4  
龙春林  顾志建  李恒   《广西植物》1989,9(4):317-321
本文报道了磨芋属(Amorphophallus Blume)三个种(其中包括两个最近发现的新种)的染色体数目和核型,其核型公式分别是: 1.结节磨芋 K(2n)=2x=26=20m(2SAT)+6sm; 2.疣柄磨芋 K(2n)=2x=28=2M+16m+8sm+2st; 3.矮磨芋 K(2n)=2x=26=20m+4sm+2st; 本文还在报道磨芋(A.konjac)两个居群的核型的基础上,提出不同居群磨芋的核型存在一定异;并比较了矮磨芋和磨芋两个居群的核型,从核型上分析了它们之间可能的关系。  相似文献   

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