首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The savannah and tropical forest biomes of Africa have a long history of expansion and contraction, and the recent and rapid spread of dry savannah habitats has influenced the spatial and temporal diversification of vertebrate taxa across this region. We used a combination of species tree and phylogeographic methods to describe the spatio-temporal changes through time and across space (= species diffusion) in a clade of seven West African lizard species in the Agama agama species group. A Bayesian species tree diffusion approach was used to compare the relative rates at which species ranges changed across the landscape. We found that some species have high diffusion rates characterized by significant movement in their range location and minor changes to their overall range size, whereas other species show little movement in their range centre with an exponential increase in range size. This discrepancy between the rates that range locations shift versus change in their relative area could be linked to populations tracking their preferred habitats through time. A continuous Bayesian phylogeography approach using a relaxed random walk model was used to estimate the timing and rate of population size change and geographic diffusion in A. picticauda, the single species in the group with an extensive African distribution from Mauritania to Ethiopia. The mean dispersal rate of A. picticauda increased dramatically throughout the Pleistocene, and a Bayesian skyride analysis supports exponential population growth over this same time period. A comparison of genetic diversity across different loci and species suggests that A. lebretoni experienced a mitochondrial selective sweep that has caused a deficit of variation at this locus in relation to nuclear loci.  相似文献   

2.
Summary Three species of lizards (Agama agama, Mabuya perrotetii, and Sceloporus orcutti) were tested for a possible increase in mean selected body temperature (MSBT) in response to intraperitoneal injection of alcohol-killed Aeromonas sobria, a gram-negative bacterium known to be pathogenic to reptiles. A paired experimental design was utilized in which each animal was given an injection of sterile saline and 1 · 1010 A. sobria. Body temperatures were monitored via indwelling cloacal thermocouples at 4-min intervals for one 12-h light period under saline injection and for two consecutive 12-h light periods under bacteria injection. Agama agama demonstrated a significant increase in MSBT on both day 1 and day 2 of bacteria injection with increases of 2.7 and 2.3°C, respectively. The latency period on day 1 averaged 6.4 h. Sceloporus orcutti demonstrated a significant decrease in MSBT on day 1 of bacteria injection and a significant increase in MSBT of 1.0°C on day 2 of bacteria injection. No fever was evident in S. orcutti until the beginning of day 2. Mabuya perrotetii did not exhibit a significant change in MSBT on either day 1 or day 2 of bacteria injection. Agama agama (family Agamidae) is the first Old World reptile to exhibit a fever response to bacteria injection, and with these results fever has now been demonstrated in the lizard families Agamidae, Iguanidae, and Teiidae.Abbreviations MSBT mean selected body temperature - T b body temperature  相似文献   

3.
Abstract

It was shown that the Weasel is distributed over the whole of Anatolia The species’ considerable size, the occasional occurrence of a white winter coat and the existence of two types of Weasels (nivalis type and minuta type) in Turkey have often lead to the wrong assumption that the Stoat (M. erminea) also occurs in Turkey.  相似文献   

4.
Abstract

The Lake of Köyceg¯iz (Köyceg¯iz Gölü) in southwest Turkey is influenced by several external factors such as sulfuric springs, :Mediterranean seawater and a relatively strong changing wind. These give rise to an exceptional hydrochemistry and hydrophysics, which are reflected in the phyto and zooplankton. The complicated layer structure of the lake is determined more by chemical gradients than by temperature. The water body is divided in two layers of differing hydrology. The upper layer is subject to full circulation while the lower one is strictly stratified by chemical gradients caused by the sulfuric sources and an influx of-Mediterranean water. The lake can be classified as meromictic. Subsurface freshwater springs may well influence the system, but to a lesser degree. Phyto- and zooplankton are characterized by a limited number of species and a low biomass. ’This is due to a very thin euphotic zone as well as the brackish character of the lake water.  相似文献   

5.
沙蜥属Phrynocephalus作为鬣蜥科Agamidae中的古北界类群,分布区复杂的地质、地理历史对该属物种形成、分化及分布格局的形成具有重要的影响.近年来,随着生物地理学理论的不断发展,各国学者从不同角度对沙蜥属的生物地理学做了大量研究.本文主要综述了这方面的研究进展;同时基于沙蜥属的研究现状对今后的研究做出展望.  相似文献   

6.
Abstract

Panthera tigris strayed at least once (1887) as far south as Mossul Liwa, Iraq. The relationship of this with neighbouring occurences is mapped.  相似文献   

7.
We incubated eggs of five Phrynocephalus species (P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii) at three constant temperatures (24℃, 28℃ and 32℃) to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size (snout-vent length and body mass) and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology.  相似文献   

8.
Abstract

The size of the Turkish population of the White-breasted Kingfisher is estimated to be about 100–150 pairs of which approx. 75% are concentrated in five localities. This makes the species vulnerable. A distribution map is given.  相似文献   

9.
Abstract

The main distribution area of the Chameleon in Turkey is the Aegean and the Mediterranean regions, however, records are also available from the Marmara region and from southeast Anatolia.  相似文献   

10.
Abstract

This paper reviews 53 records of the Whimbrel (Numenius phaeopus) in Bulgaria (1912–1989) from published and unpublished sources. The phonology, distribution, ecology and behaviour of these migrants are described and discussed. Attention is drawn to “pale” Whimbrels which may belong to the rare subspecies albuaxillaris.  相似文献   

11.
12.
We report new localities and range extensions for four vipers from Turkey. The distribution of Montivipera wagneri is extended substantially southwards into Mu? province, showing that this species is not endemic to the Aras valley as previously stated in the literature. Similarly, an unverified photograph of Montivipera albizona from Erzincan province, at its currently known eastern limit, was confirmed with new material, and its range is extended substantially southwards to the Anamos (Nur) Mountains in Hatay province. Smaller range extensions are reported for Vipera ammodytes transcaucasiana and V. darevskii.  相似文献   

13.
Abstract

The two subspecies of Ophisaurus apodus represent different ecotypes: thracicus is a coastal type, which occurs in Turkey along all coasts (but only local along the Black Sea coast), whereas nominate apodus is an inland type which is found in Turkey only in the extreme east. Anguis fragilis is confined to areas in which the monthly mean precipitation is above 20 mm.  相似文献   

14.
贵南沙蜥分布在青海省贵南县的一片长×宽约为30 km×20 km的连续沙丘,该沙丘被周缘草地隔离,贵南沙蜥主要在沙地与草地接触带的沙地一侧活动。采用3条样线共150个陷阱研究贵南沙蜥在草地与沙地交界线两侧的活动洞穴空间分布特征与潜在的可利用性昆虫食物资源多样性,并分析洞穴空间分布特征与昆虫种类以及数量分布的关系。研究共捕获1236个昆虫个体,隶属于2纲10目26科42种,其中昆虫纲有7目21科37种978个,蛛形纲有3目5科5种258个;草地采集的昆虫有2纲9目22科37种570个,沙地有2纲9目21科33种666个。草地昆虫的Shannon-Wiener,Simpson多样性指数与均匀度指数均大于沙地,表明草地的昆虫食物资源较丰富且分布均匀。研究表明贵南沙蜥在沙地环境活动洞穴数量较多,且离交界线越近洞穴分布数量越多;草地生境活动洞穴空间分布与离交界线距离无相关性,相对沙地数量较少且空间上分布较均匀。草地样方捕获的昆虫种类和数量以及沙地样方捕获的昆虫数量都与离分界线的距离无关,但沙地上昆虫种类与离分界线的距离呈高度负相关。研究表明贵南沙蜥沙地活动洞穴空间分布与昆虫种类分布特征显著相关。  相似文献   

15.
Abstract

A Trumpeter Finch was recorded on Nemrud Mountain in Eastern Anatolia on 17.8.1987. Together with some other unpublished records, this indicates breeding at a few sites in eastern Turkey.  相似文献   

16.
17.
形态,染色体特征聚类分析表明过去归入青海沙蜥的天祝,贵德居群被聚为一支,而青海沙蜥的其它居群和红原沙蜥 聚为另一支,证明贵,在祝居群与青海沙蜥有显著区别,应当恢复贵德沙蜥Phrynocephalus putjatia为有效种。贵德沙蜥与青海沙蜥的主要鉴别特重是前者的尾长大于吻肛长,后者的尾短,小于吻肛长,前者背鳞100枚以上,后者背鳞不到100枚。红原沙蜥Phrynocephalus hongyuanensis与青海沙蜥的染色体和形态特征相似,应归隶青海沙蜥。  相似文献   

18.
Abstract

The distribution of the Indian Crested Porcupine Hystrtx indica in Iraq is described, with 19 additional new localities. The population has apparently has been declining during the last twenty years. Preganancy was recorded between April and September, suggesting at least two litters per year. The mean number of embryos was 2.3 per female. 98–100% of the stomach content consisted of plant material.  相似文献   

19.
Abstract

The beetle Osphranteria coerulescens, until now known only from a few places in Iran and in Syria is reported from four sites in Eastern Turkey.  相似文献   

20.
三种沙蜥核型的比较研究   总被引:8,自引:1,他引:7  
本文报道了白条沙蜥Phrynocephalus albolineatus,东疆沙蜥P.grumgrizimaloi及西藏沙蜥P.theobaldi的核型,西藏沙蜥2n=22I+26m,NF=48,其余二者2n=22I+24m,NF=46。与同属已知其它的核型进行了比较。沙蜥属中至少存在2b=46和2n=48两种核型类群,二者可能与“沙蜥属物种形成的两个起源中心”的假说相关。讨论了沙蜥属中的核型演化  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号