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 250 毫秒
1.
This study investigates length–weight and length–length relationships of four shad species (Alosa caspia caspia, Alosa immaculata, Alosa maeotica, Alosa tanaica) captured in the western Black Sea coast of Turkey. A total of 686 specimens, 355 females and 331 males, were caught by gill net, trammel net and longline from 2006 through 2007 along the western Black Sea coast of Turkey. The relationships of total length (TL), fork length (FL) and standard length (SL) are presented for inhabiting in the Black Sea four shad species and the relationships between total length (TL) and body weight (BW) from the two localities, Sile and Karasu in the western Black Sea coast of Turkey. The Length–weight relationships generally indicated positive allometric growth in Alosa species for both males and females and an isometric growth for A. immaculata females. The coefficient b ranged from a minimum 2.97 for females of A. immaculata to a maximum 3.75 for both sexes A. c. caspia. Results indicated that the length–length relationship between the three length measurements were highly correlated (r2 > 0.99, P < 0.001).  相似文献   

2.
3.
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   

4.
The Lebanon Lizard (Phoenicolacerta laevis) occurs on the Levantine coast and scattered populations are found in isolated coastal habitats along the southern and south-western coast of Turkey. We found an isolated but dense population of this species at and around the castle of Anaklia on Georgia’s Black Sea Coast, near the mouth of the river Enguri. The analysis of mitochondrial cytochrome b sequence suggests closeness of this population to the populations in the provinces of Kahramanmara?, Adana and Içel in southern Turkey, rather than to those in Lebanon and Israel. It is thought that the species was introduced from a Turkish region to Anaklia, which was an important trade location at the eastern Black Sea coast until the late 18th century. This is the first established location of this species outside the eastern Mediterranean area. Climate and competition with rock lizards of the genus Darevskia are the most likely reasons preventing expansion of the species into the neighboring areas of Western Georgia.  相似文献   

5.
Hotspots of intraspecific genetic diversity, which are of primary importance for the conservation of species, have been associated with glacial refugia, that is areas where species survived the Quaternary climatic oscillations. However, the proximate mechanisms generating these hotspots remain an open issue. Hotspots may reflect the long‐term persistence of large refugial populations; alternatively, they may result from allopatric differentiation between small and isolated populations, that later admixed. Here, we test these two scenarios in a widely distributed species of tree frog, Hyla orientalis, which inhabits Asia Minor and southeastern Europe. We apply a fine‐scale phylogeographic survey, combining fast‐evolving mitochondrial and nuclear markers, with a dense sampling throughout the range, as well as ecological niche modelling, to understand what shaped the genetic variation of this species. We documented an important diversity centre around the Black Sea, composed of multiple allopatric and/or parapatric diversifications, likely driven by a combination of Pleistocene climatic fluctuations and complex regional topography. Remarkably, this diversification forms a ring around the Black Sea, from the Caucasus through Anatolia and eastern Europe, with terminal forms coming into contact and partially admixing in Crimea. Our results support the view that glacial refugia generate rather than host genetic diversity and can also function as evolutionary melting pots of biodiversity. Moreover, we report a new case of ring diversification, triggered by a large, yet cohesive dispersal barrier, a very rare situation in nature. Finally, we emphasize the Black Sea region as an important centre of intraspecific diversity in the Palearctic with implications for conservation.  相似文献   

6.
A new species of Delamarella Chappuis, 1954 (Copepoda, Harpacticoida, Latiremidae), D. obscura sp. nov. , is described from sandy beaches along the western Black Sea coast of Turkey, using both light and scanning electron microscopy. Additional morphological observations of the closely related D. galateae Cottarelli, 1971 are presented, based on topotype material from Sardinia and newly collected specimens from mainland Italy. Previous records of D. karamani Petkovski, 1957 from the Bulgarian Black Sea coast are based on misidentifications and should be attributed to D. obscura sp. nov. All three species are morphologically similar, and criteria based on meristic and ornamentation characters are provided to distinguish them. Examination of copepodid V ♂ intermoult stages provided new insights into the morphology of the highly transformed P4 exopod of the adult male and its homology with reference to the female. A reassessment of the generic distinctiveness of Delamarella and the monotypic genus Latiremus Božić, 1969 revealed that morphological criteria, traditionally employed to separate both genera, are all essentially unsound and based on erroneous reports in the literature. Consequently, Latiremus is relegated to a junior synonym of the type genus, leaving Delamarella and Arbutifera Huys & Kunz, 1988 as the only remaining valid genera in the family.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 145 , 263–281.  相似文献   

7.
For many European species, the mountains of the Alps and the Pyrenees have acted as significant barriers to northwards colonization from southern glacial refugia. To the east, the Caucasus Mountains would seem to have been a similar barrier to the white‐breasted hedgehog (Erinaceus concolor). A deep divergence among hedgehog mitochondrial sequences to the north and south of the Caucasus Mountains suggests two colonization routes, originating from separate refugial regions and divided by this mountain barrier. From a Balkan refugium, hedgehogs have colonized northwards into Russia and to the northern foothills of the Caucasus Mountains. The origins of hedgehogs colonizing the southern parts of the Caucasus are not entirely clear, although fossil and climatic data suggest a glacial refugium on the southern shores of the Black Sea. Divergence within the southern group indicates a long‐standing fragmentation within such a refugium or the presence of further cryptic refugia in Turkey and the Near East. The Caucasus barrier would seem to have been an important factor in structuring the late Pleistocene distribution of species.  相似文献   

8.
The European pond turtle, Emys orbicularis (Linnaeus, 1758), is one of the world's most widely distributed chelonian species. We investigated its mitochondrial phylogeography and demography using ∼1300 cyt b sequences from the entire range, with a focus on the eastern part, in particular on Turkey, where the species currently suffers massive losses. Coloration data from >1450 turtles were compared with mtDNA differentiation to assess the validity of the currently accepted subspecies from Turkey, the Black Sea Region, the Transcaucasus, and Iran. Our study region harbors considerable part of the mtDNA diversity of Emys, including a newly discovered lineage and 16 new haplotypes. In this area corresponding to approximately one-third of the entire distribution range, six out of the ten mitochondrial lineages and about half of all 72 haplotypes occur. Two mitochondrial lineages (VIII, X) are confined to small ranges along the southern coast of Turkey, another lineage (I) occupies the remainder of Turkey, the entire Black Sea Region, and the north-eastern part of the species’ range. In the south-western corner of the Black Sea and in the Aegean Region, two lineages (II, IV) occur that have their main distribution areas farther west. In the Transcaucasus and northern Iran, another endemic lineage (VII) is found. Lineage I is the largest and most diverse of all lineages and has its greatest diversity in Anatolia. Phylogeographic and demographic data suggest Anatolia as an ancient glacial refuge for turtles harboring mitochondrial lineages I, VIII and X, and that Anatolia and the Black Sea coasts constitute a hotspot for a younger burst of diversification within lineage I. These two regions correspond to the glacial refuge from which lineage I turtles recolonized more northerly parts of the range in the Holocene; lineage II represents an off-shoot of lineage I that became isolated in a westward-located refuge in the south-eastern Balkans during a previous Pleistocene glacial. Our data on coloration indicate that such characters have only limited value for delineating evolutionarily significant units. We propose to reduce the number of subspecies using mtDNA lineages as arbiter, and to recognize three subspecies as valid in Turkey, the Black Sea Region, the Transcaucasus and Iran: Emys orbicularis orbicularis (mtDNA lineage I); E. o. eiselti Fritz et al., 1998 (X); and E. o. persica Eichwald, 1831 (VII). However, the southern Turkish lineage VIII most probably represents an additional undescribed subspecies. Both southern Turkish endemics are critically endangered, with only three surviving populations of fewer than 30 adults each. We recommend establishing sanctuaries for them, and including them in the IUCN Red List.  相似文献   

9.
Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level.  相似文献   

10.
Microsatellite genetic variation of Asian populations of Dolly Varden char   总被引:1,自引:0,他引:1  
Genetic variation at eight microsatellite loci was examined in 21 populations of Dolly Varden charrs, Salvelinus malma, representing five geographical regions (Kamchatka Peninsula, Sea of Okhotsk coast, Sea of Japan coast, Sakhalin Island, and Kuril islands). Hierarchical analysis of molecular variance showed that 11% (58% in terms of R-statistics) of the variation was distributed among of northern subspecies of Dolly Varden, Salvelinus malma malma and southern Asian Dolly Varden, S. m. krascheninnikovi while similar values were attributed to the among-regional level within northern Dolly Varden 9% (7%) and southern Asian Dolly Varden 11% (14%). Permutation-based tests indicated a mutational component to genetic differentiation based on allelic size variance and suggested that divergence of the two subspecies had occurred at least 3,000 generations ago. On large spatial scales (within the Asian range of the species), populations clustered according to their geographical location. On smaller scales (within regions and subregions) correlation between genetic and geographic distances was not significant. Northern Dolly Varden has higher allelic diversity and more private alleles than southern subspecies, this probably indicating differences in demographic history.  相似文献   

11.
12.
Floristic differentiation of the oriental beech (Fagus orientalis Lipsky) forests in Turkey and Bulgaria was investigated and the role of geographical and topographical factors in this differentiation was assessed. After geographical and ecological stratification of the available 922 relevés, 288 remained. Classification, by applying cluster analysis, resulted in seven vegetation units defined by species composition which represent the geographical and ecological variation of Fagus orientalis forests. DCA ordination was applied to these units by passively projecting their chorological structure, as supplementary variables. For more detailed interpretation of vegetation types with similar geographic distribution patterns, PCA was applied by passively projecting the chorological elements, life-forms and topographical factors as supplementary variables. Seven vegetation units representing the geographical and ecological variety of Fagus orientalis forests were described. Four vegetation units represent the core area of Fagus orientalis distribution on the western and middle coast of the Black Sea region (Euxine region); the remaining three types represent the distribution in the eastern Black Sea region (Colchic region), the distribution in western and southern Anatolia under the influence of the Mediterranean climate and the distribution in the transitional zone from the Euxine region to the continental parts of Inner Anatolia, respectively. The four vegetation types in Euxine region reflect the decreasing effect of Black Sea towards Inner Anatolia, as well as altitudinal differences, except the forest type representing forests on calcareous sites. The other three vegetation units represent ravine, lowland to montane and altimontane forests in Euxine region. Fagus orientalis forests could be distinguished by their floristic composition, their chorological elements and life-forms spectra, which reflect a geographical and ecological gradients.  相似文献   

13.
The transition zone between the Mediterranean and Atlantic basins has been extensively addressed in phylogeographical studies of marine species. However, biases exist towards the analysis of highly dispersive species, and there is a higher sampling effort in European coasts compared to North Africa. This may be hindering a detailed understanding of the historical and contemporary processes that shaped patterns of population genetic structure in the region. In the present study, we investigated the phylogeographical and phylogenetic patterns of mitochondrial cytochrome c oxidase subunit I sequences from a species with direct development and low dispersal abilities, Stenosoma nadejda (Rezig, 1989). The study area included 13 localities along the Atlantic and Mediterranean North African coasts, as well as the Alboran Sea. A new Stenosoma species, from the coasts of Algeria and Alboran Island, was discovered. For S. nadejda, phylogeographical analyses revealed three distinct clades: one in the Iberian Atlantic plus the Alboran Sea, one in the western Mediterranean, and another in the Atlantic coast of Africa. Haplotypes from the Alboran Island were more related to those from the western Mediterranean coast (east of the Almeria–Oran Front). Given the strong differentiation, it is probable that this species survived in multiple glacial refugia during the Pleistocenic glaciations. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 419–431.  相似文献   

14.
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   

15.
Pinus brutia var. pityusa (Steven) Silba (Calabrian pine) is considered a vulnerable species because of reductions in its population sizes linked to habitat decline in recent decades. Global warming alongside the collateral modification of precipitation regimes may markedly affect the distribution ranges of this species.In this dendroecological study, we identified the most influential climatic factors affecting the radial growth of P. brutia on the northern and eastern coasts of the Black Sea among the northern refugia of this species. Chronologies from five sites located on the Crimea Peninsula and the Caucasian coast and exposed to varying climatic conditions were used in this analysis. The study of environmental factors controlling the growth of P. brutia trees in the coastal populations of Crimea and the Caucasus revealed that within the longitudinal transect, which encompasses a specific range of climatic conditions, correlations between climate and the growth of P. brutia under analogous orographic conditions are similar.Aridisation of the dry Crimean climate in 1981–2012 led to an increase in the tree growth response. In the same period, populations of P. brutia trees growing in the subtropical climate of the Black Sea coast exhibited a weakened growth response to the point of disappearance. The northern populations of P. brutia, which are at the climatic limit of the species’ distribution, are exposed to a high risk of increasing climate aridisation. Our findings could provide useful information for further research on the effects of climate change on Black Sea coastal forest ecosystems.  相似文献   

16.
Both sexes of a new species of Taurocletodes Kunz, 1975 (Copepoda, Harpacticoida, Canthocamptidae incertae sedis ) are described from sandy beaches along the Black Sea coast of Turkey. The genus Taurocletodes is removed from its synonymy with Parepactophanes Kunz, 1935 and re-instated as a valid genus, accommodating the type species T. dubius (Noodt, 1958) comb. nov. and T. tumenae sp. nov. Both genera can be differentiated by major differences in the segmentation of P1–P3 endopods, the absence/presence of penicillate setae on P1 endopod, the number of outer spines on P2–P4 exp-3, the armature of P2–P4 endopods and the sexual dimorphism of P2 endopod and P3 exopod. T. tumenae sp. nov. and T. dubius are morphologically very similar, differing in morphometric characters related to the endopodal segmentation of P1 and P4, and armature of the male P5. The controversial taxonomic status of Parepactophanes and Taurocletodes within the family Canthocamptidae is discussed.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 469−486.  相似文献   

17.
Glirids are arboreal rodents that are difficult to monitor due to their nocturnal activity and their relatively low density. We compared results from footprint tunnels with those from two other monitoring methods (nest boxes and nesting tubes) for three dormouse species in an occupancy framework. Footprint tunnels performed better than the other two methods for the hazel dormouse Muscardinus avellanarius and the edible dormouse Glis glis, and were the only method which detected the garden dormouse Eliomys quercinus. Our findings provide evidence to support the effectiveness of footprint tunnels in monitoring the occurrence of dormouse species in comparison with other methods.  相似文献   

18.
The presence of Acartia tonsa in Black Sea waters (South Crimean coast, Ukraine) is reported for the first time. A. tonsa may be a recently introduced species in the Black Sea. Morphological features of the adults have been shown by S.E.M.  相似文献   

19.
The metal(loid)s are mainly transported to the Black Sea via rivers and affect the coastal area where fisheries are intensive. Chamelea gallina (striped venus clam) is the most abundant mollusk species in the Black Sea and used as a bioindicator for monitoring of metal(loid) pollution. In this respect, the concentrations of As, Cd, Cr, Cu, Pb, and Zn in C. gallina collected from 16 different locations along the Black Sea coast (Turkey, Bulgaria, and Russia) were determined and evaluated for the potential human health risk. The results obtained were found to be below the maximum permissible limits indicated in the food safety guidelines. Similarly, the analyzed metal(loid)s did not pose a potential hazard to humans for consumption of the C. gallina, regarding provisional tolerable weekly intake described by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Moreover, target hazard quotient and hazard index were found to be lower than 1 for not only average consumer but also the consumer who consumed a portion (160 g) once a week. In contrast, consumption of C. gallina could cause health risks for Cd and As in case of increasing portion sizes.  相似文献   

20.
We sequenced 1077 bp of the mitochondrial cytochrome b gene and 511 bp of the nuclear Apolipoprotein B gene in bicoloured shrew (Crocidura leucodon, Soricidae) populations ranging from France to Georgia. The aims of the study were to identify the main genetic clades within this species and the influence of Pleistocene climatic variations on the respective clades. The mitochondrial analyses revealed a European clade distributed from France eastwards to north-western Turkey and a Near East clade distributed from Georgia to Romania; the two clades separated during the Middle Pleistocene. We clearly identified a population expansion after a bottleneck for the European clade based on mitochondrial and nuclear sequencing data; this expansion was not observed for the eastern clade. We hypothesize that the western population was confined to a small Italo-Balkanic refugium, whereas the eastern population subsisted in several refugia along the southern coast of the Black Sea.  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