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1.
The African members of the remarkably disjunct Afro-American genus Thamnosma are revised. Six species are recognized, T africana, T. rhodesica and T. crenata in southern Africa, and T. somalensis, T. socotrana and T. hirschii in the Horn of Africa region, including the southern part of the Arabian Peninsula and Socotra. T. somalensis , sp. nov., is described from north-eastern Somalia. T. crenata , comb, nov., is based on T. africana var. crenata . A key to the species is given and two lectotypes and one neotype are selected.  相似文献   

2.
The Red Sea has had a profound biogeographic effect on organisms with Afro-Asian distributions, resulting in complex patterns of admixture on the Arabian Peninsula. We investigate the phylogenetic affinities of a monitor lizard (Varanus yemenensis) restricted to the southwestern Arabian Peninsula by sequencing all African monitor species and several Asian monitor species for the mitochondrial gene ND2 and the nuclear marker RAG-1. We find evidence that V. yemenensis is of African origin, being most closely related to the white-throat monitor, V. albigularis, an African species complex distributed from the Horn of Africa to southern Africa. Using divergence-dating analyses, we investigate several biogeographic hypotheses to infer the likely mechanism of colonization of the Arabian Peninsula by this species. Our results reveal that both dispersal across a southern land bridge and overwater dispersal are potential explanations. The patterns observed in V. yemenensis are contrasted with other taxa having similar Afro-Arabian disjunct distributions to better understand the complex biogeographic history of this region.  相似文献   

3.
Baboons (Mammalia: Primates, Papio) are found primarily on the continent of Africa, but the range of hamadryas baboons (Papio hamadryas) extends to the Arabian Peninsula, and the origin of Arabian populations is unclear. To estimate the timing of the divergence between Arabian and African hamadryas populations we analyzed mitochondrial DNA (mtDNA) sequences from individuals of Arabian and African origin, and from representatives of the other major baboon taxa. The oldest hamadryas mitochondrial lineages in the Arabian Peninsula form an ancient trichotomy with the two major African lineages. This suggests that Arabia was colonized by hamadryas very soon after the appearance of the distinctive hamadryas phenotype, both events perhaps coinciding with a mid-Pleistocene stage of dry climate and low sea-level. The most closely related Arabian and African mtDNA haplotypes coalesce at approximately 35 ka, suggesting that no gene flow between African and Arabian baboons has occurred since the end of the last ice age, when a land bridge at the southern sill of the Red Sea was submerged. The mitochondrial paraphyly of Ethiopian hamadryas and anubis (P. anubis) baboons suggests an extensive and complex history of sex-specific introgression.  相似文献   

4.
Aim The identification of the marine plant communities of two islands from different upwelling areas of the Arabian Sea, with a similar diversity in biotopes. A comparison of the species composition of these macroalgal communities and their biogeographical affinities within the Indian Ocean should give insight into the biogeographical position of the Arabian Sea within the larger Indian Ocean. The incorporation of environmental parameters in the analysis is instructive in understanding their importance in shaping the diverse marine assemblages of the Arabian Sea. Location Arabian Sea: (1) the Socotra Archipelago (Yemen; 12.47° N, 53.87° E) in the Somali upwelling area, (2) Masirah Island (Oman; 20.42° N, 58.79° E) in the upwelling area of the southern Arabian Peninsula. Methods The marine flora of different biotopes around both islands were examined by means of qualitative assessments. Ordination analysis [detrended correspondence analysis (DCA)] was used to identify the different plant communities and to correlate these with environmental parameters. The species composition of the identified communities were compared (tripartite similarity index) and their biogeographical affinity with nations bordering the Indian Ocean was determined. Indicator species analyses were performed to identify the characteristic species of the different plant communities and their biotopes. Results The DCA analysis shows a clustering of sites (plant communities) corresponding with their geographical position, linked in turn to the prevailing environmental conditions of the different coastal areas. The combined interpretation of the ordination, similarity and biogeographical analyses results in the aggregation of similar plant communities of both upwelling areas into four biotopes. Main conclusions The north coast communities of Socotra and the west coast communities of Masirah can be grouped into three biotopes related to the degree of exposure (to upwelling) and sedimentation. These biotopes are typified by indicator species, characteristic for specific substrata, and have a high biogeographical affinity with the East African coast. The plant communities of Socotra's south coast and Masirah's east coast constitute a fourth biotope, being diverse and species rich, typified by a large proportion of red macroalgae including the characteristic species of the unique Arabian Sea flora. This biotope has a pronounced biogeographical affinity with distant regions (disjunctly distributed taxa) as South Africa's East Coast and Western Australia. Within the different biotopes, the communities of Masirah are more divergent from an East African flora in comparison to Socotra, the latter being a stepping stone between the East African and Arabian Sea flora.  相似文献   

5.
Polystoma claudecombesi is described as a new species of the Polystomatidae (Monogenea) parasitic in the urinary bladder of the anuran host Rana angolensis. This parasite was collected at three localities in South Africa, namely Vernon Crookes Nature Reserve in Natal province, Witsieshoek Mountain Resort in the north-eastern Orange Free State and Bovenste Oog in the province of Transvaal. It is the largest African polystome described to date. Prevalence at Vernon Crookes Nature Reserve was 4.0% and 2.7% in two successive years, with a mean intensity of 1.0 (n=25 and 36, respectively). One of the two R. angolensis from Witsieshoek was infected with 5 parasites. The diversity and distribution of southern African polystomes is also discussed.  相似文献   

6.
An attempt is made to apply cluster analysis to comparison of local faunas in the Northern Hemisphere at the species level by the example of the subfamily Arctiinae (Lepidoptera, Arctiidae). A total of 200 North African, Eurasian (New Guinea inclusive), and North American (north of the United Mexican States) local faunas have been considered. It is found that the circumarctic fauna is clearly separated from the Palearctic and Nearctic ones, being closer to the former only at the level of genera. Therefore, it is not reasonable to recognize the united European-Canadian subprovince of the boreal belt according to the tiger moth faunas. The Palearctic tiger moth fauna is characterized by relatively smooth variations within the boreal, subboreal, and western subtropical belts. The fauna gradually changes from the Amur catchment area to South China, Himalayas, and India so that all fauna types of these regions are closely related to one another and, to a lesser extent, to equatorial fauna types of Southeast Asia islands. The boundary between the Palearctic and Oriental (Indo-Malayan) provinces should be drawn north of the Yangtze catchment area. The most dramatic fauna change at the species level takes place between North China and the Yangtze catchment, and at the genus level, between Northern and Northeastern China. It is reasonable to establish a broad transition area between the two zoogeographic provinces in Eastern Asia. On the grounds of the nonuniform tiger moth fauna, the South Chinese-East Himalayan subprovince should be assigned to the Oriental (Indo-Malayan) province rather than the Palearctic one, as was repeatedly proposed. The Southwest-Asian fauna (Arabian Peninsula and southern Iran) is transitional between the Palearctic, African, and Oriental ones. Many African taxa penetrate to the west and south of the Arabian Peninsula, whereas Oriental and Paleotropical species penetrate to southern Iran. It is reasonable to elevate considerably the rank of the Quinghai-Tibet highland fauna by distinguishing its habitat as a separate zoogeographic subprovince, because the similarity between this fauna type and any other Palearctic fauna at the species level is much less than between temperate faunas of the Palearctic and Nearctic. The assignment of this fauna to the Palearctic is confirmed only at the genus level.  相似文献   

7.
  • 1.1. Aspects of the physiology of two southern African scorpions have been examined. The scorpions are the large desert species Parabuthus villosus (Peters) (Buthidae) and the more mesic, burrowing species Opisthophthalmus capensis (Herbst) (Scorpionidae).
  • 2.2. Evaporative water losses were higher in Opisthophthalmus at all temperatures.
  • 3.3. Analysis of haemolymph during prolonged desiccation showed good osmotic and ionic regulation in Parabuthus but no regulation in Opisthophthalmus.
  • 4.4. Oxygen consumption of Parabuthus was measured after acclimation to 10 and 30°C. Metabolic rates were extremely low but there was no metabolic compensation to increased temperatures.
  相似文献   

8.
The material of Micromeria s.s. ( M. sect. Micromeria ) from tropical to southern Africa and the Arabian Peninsula is revised. The endemic Ethiopian M. unguentaria Schweinf. is retained as a species, while the other African and Arabian material of Micromeria is included in M. imbricata (Forssk.) C. Chr. M. imbricata is divided into the following three varieties: var. imbricata , which is very polymorphic, widespread in the African highlands, and also occurs in Arabia; var. rhodesiaca (Elly Walther & K.H. Walther) Ryding, which occurs in the highlands of Malawi, Mozambique and Zimbabwe; and var. villosa (Elly Walther & K.H. Walther) Ryding, which occurs in montane to alpine areas of Ethiopia and East Africa. Discontinuities in the variation within var. imbricata , observed at some localities, are suggested to be a result of partial autogamy. Problems with delimitation between M. imbricata , the East Asiatic M. biflora (Buch.-Ham. ex D.Don) Benth. and some Mediterranean species are discussed.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 427–446.  相似文献   

9.
The genus Crinum L. is the only pantropical genus of the Amaryllidaceae. Phylogenetic and biogeographical analyses of nrDNA ITS and plastid trnL-F sequences for all continental groups of the genus Crinum and related African genera are presented, with the genus Amaryllis used as outgroup. ITS indicates that C. baumii is more closely related to Ammocharis and Cybistetes than to Crinum sensu stricto . Three clades are resolved in Crinum s.s. One unites a monophyletic American group with tropical and North African species. The second includes all southern African species and the Australian endemic C. flaccidum . The third includes monophyletic Madagascar, Australasian and Sino-Himalayan clades, with southern African species. The trnL-F phylogeny resolves an American and an Asian/Madagscar clade, and confirms the relationship of C. flaccidum with species endemic to southern Africa. The salverform, actinomorphic perianths of subg. Crinum appear to have evolved several times in the genus from ancestors with zygomorphic perianths (subg. Codonocrinum ), thus neither subgenus is monophyletic. Biogeographical analyses place the origin of Crinum in southern Africa, as the region is optimized at all ancestral nodes in the tree topology, and in basal interior nodes of all but one of the major clades. The genus underwent three major waves of radiation corresponding to the three main clades resolved in our trees. Two entries into Australia for the genus are indicated, as are separate Sino-Himalayan and Australasian dispersal events.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 349–363.  相似文献   

10.
Justicia areysiana Deflers (Acanthaceae) is an endemic shrub of the monsoon affected coastal mountains of the southern Arabian Peninsula with ballochorous seed dispersal. Its occurrence in a vegetation belt of relics of the (semi)-evergreen Afro-montane woodland characterised by Olea europaea subsp. cuspidata and Juniperus procera above an elevation of c. 750-800 m is strongly dependent on the activity of the Indian Ocean southwest monsoon. Therefore, the species offers a good model to study the palaeo-climate induced habitat fragmentation of the once continuous distribution range of the Afro-montane woodland belt on the southern Arabian Peninsula. Thirteen populations from the total distribution range of the species were analysed using AFLP fingerprinting and show a distinct geographic distribution pattern with a main split between eastern (Hawf Mountains/Dhofar) and western/central populations (Jabal Urays, Jabal Gedu, Kor Seiban). Our results on the genetic differentiation of populations clearly demonstrate the strong isolation among populations and confirm geographical patterns found in former studies based on chloroplast haplotypes. The dating of the main regional split between eastern and western/central populations based on nrDNA ITS sequence variation, is dated to 0.8–1.8 Myr before present. This indicates drastic habitat fragmentation processes during the Pleistocene which are compatible with periods of aridisation assumed for the African continent at around 1.7 Myr and 1.0 Myr before present.  相似文献   

11.
Zoogeography of the coral reef fishes of the Socotra Archipelago   总被引:1,自引:0,他引:1  
Fish communities and habitats were studied at the Socotra archipelago (Gulf of Aden, ≈12°N 54°E). Extensive and unexpected hermatypic coral communities were recorded, at the centre of a 2200 km gap in knowledge of species and habitat distributions which coincides with a change from a western Indian Ocean coral reef fauna to an Arabian one. The fish assemblage associated with the Socotra archipelago corals is predominantly south Arabian. An east African influence, minimal on the mainland coasts of Arabia, is more evident here, and results in previously unrecorded sympatry between Arabian endemic species and their Indian Ocean sister taxa. A study of distributions of Chaetodontidae (butterflyfishes) in the north-western Indian Ocean reveals a number of distinct patterns, with a trend for species replacement along a track from the northern Red Sea to the Indian Ocean. A major feature of the reef fish zoogeography of the region is found to be a distinct south Arabian area, characterized by a 'pseudo-high latitude effect' which results from seasonal cold water upwelling along the Arabian sea coasts of Yemen and Oman and the Indian Ocean coast of Somalia. This south Arabian feature is consistent across a wide range of fish families. It is most pronounced in Oman and Yemen, and although it is the dominant influence at Socotra it is slightly 'diluted' here by the east African influence. The south Arabian area wholly or partly accounts for most of the major marine zoogeographic features around Arabia, and is the principal feature fragmenting Arabian coastal fish assemblages, and separating them from those of the wider Indo-west Pacific.  相似文献   

12.
Two new thick‐tail scorpions in the genus Parabuthus Pocock, 1890 are described from the gravel plains of the Central Namib Desert, Namibia: Parabuthus glabrimanus sp. nov. ; Parabuthus setiventer sp. nov. The two new species occupy discrete distributional ranges, allopatric with the closely related species Parabuthus gracilis Lamoral, 1979 and Parabuthus nanus Lamoral, 1979. The distributions of the four species are mapped and a key provided for their identification. Revised diagnoses are provided for P. gracilis and P. nanus. The two new species are added to a previously published morphological character matrix for Parabuthus species and their phylogenetic positions determined in a reanalysis of Parabuthus phylogeny. Parabuthus setiventer sp. nov. is found to be the sister species of P. nanus, whereas P. glabrimanus sp. nov. is sister to a monophyletic group comprising P. gracilis, P. nanus, and P. setiventer sp. nov. The discovery of two new scorpion species endemic to the Central Namib gravel plains contributes to a growing body of evidence that this barren and desolate region is a hotspot of arachnid species richness and endemism. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 673–710.  相似文献   

13.
An attempt is made to apply cluster analysis to comparison of local faunas in the Northern Hemisphere at the genus level by the example of the subfamily Arctiinae (Lepidoptera, Arctiidae). A total of 200 North African, Eurasian (to New Guinea inclusive), and North American (north of the United Mexican States) local faunas have been considered. It is found that the arctic fauna is clearly detached from the Palearctic and Nearctic faunas, being closer to the former. Therefore, it is not reasonable to recognize the united European-Canadian subprovince of the boreal province according to the tiger moth faunas. The Palearctic tiger moth fauna is characterized by relatively smooth variations within the boreal, subboreal, and western subtropical belts. The boundary between the Palearctic and the Oriental (Indo-Malayan) provinces should be drawn north of the Yangtze catchment area. The most dramatic fauna change at the genus level takes place between North and Northeast China. It is reasonable to recognize a broad transition area between the two zoogeographic provinces in Eastern Asia. On the grounds of the nonuniform tiger moth fauna, the South Chinese-East Himalayan subprovince should be assigned to the Oriental (Indo-Malayan) province rather than the Palearctic, as was repeatedly proposed. The Southwest-Asian fauna (Arabian Peninsula and southern Iran) is transitional between the Palearctic, African, and Oriental ones. Many African genera reach the west and south of the Arabian Peninsula, whereas Oriental and Paleotropical genera reach southern Iran.  相似文献   

14.
The hamadryas baboon (Papio hamadryas hamadryas) is found both in East Africa and western Arabia and is the only free-ranging nonhuman primate in Arabia. It has been hypothesized that hamadryas baboons colonized Arabia in the recent past and were possibly even transported there by humans. We investigated the phylogeography of hamadryas baboons by sequencing a portion of the control region of mtDNA in 107 baboons from four Saudi Arabian populations and combing these data with published data from Eritrean (African) P. h. hamadryas. Analysis grouped sequences into three distinct clades, with clade 1 found only in Arabia, clade 3 found only in Africa, but clade 2 found in both Arabian and African P. h. hamadryas and also in the olive baboon, P. h. anubis. Patterns of variation within Arabia are neither compatible with the recent colonization of Arabia, implying that baboons were not transported there by humans, nor with a northerly route of colonization of Arabia. We propose that hamadryas baboons reached Arabia via land bridges that have formed periodically during glacial maxima at the straits of Bab el Mandab in the southern Red Sea. We suggest that the genetic differentiation of Arabian from African populations suggests that Arabian populations have a higher conservation status than recognized previously.  相似文献   

15.
The mature stomatal morphology of 11 southern African species of Eugenia , and also of E. uniflora L. (naturalized) and E. incerta Diimmer (a garden plant of unknown origin) has been studied by light and scanning electron microscopy.
Leaves of all the species are hypostomatic and water-stomata are occasionally present. Two different stomatal types, X and Y, differing mainly in their cuticular ornamentation, were found in the southern African species. The grouping of species based on stomatal characters supports a previous grouping of species on the basis of periderm and seed characters.
Conspicuous lipid bodies, usually present in the subsidiary cells, are limited to the southern African species. Although the subsidiary cells do not differ in shape and size from adjacent epidermal cells, their contents often have a higher tannin content than ordinary epidermal cells. The variable patterns of arrangement of the three to five subsidiary cells makes it difficult to identify the stomata with existing classifications based on mature topography. Thus, a new term 'anomostaurocytic' is proposed for the stomatal type found in the southern African species.
Stomata of E. uniflora and E. incerta are paracytic and anomocytic respectively, and the cuticular ornamentation of their stomata differs from those of the southern African species. The view that E. incerta is not closely related to the southern African species is supported by differences in its cuticular ornamentation, lack of lipid bodies in the subsidiary cells, anomocytic stomata and prominent T-pieces at the guard cell poles.  相似文献   

16.
17.
《Nordic Journal of Botany》2007,25(3-4):217-226
Euclea schimperi, a widespread Afromontane shrub or tree, occurs in the Arabian Peninsula in fragmented, semi-evergreen or evergreen woodland refugia in wet escarpment localities of the western and southern mountain chains. In the southern coastal mountains, the (semi-) evergreen woodland with E. schimperi is close to its ecological limit and consequently today very rare, with the exception of the monsoonal fog oases of east Yemen and south Oman in the central south coast of the Arabian Peninsula. Due to the steep precipitation gradient from the centre to the western edge in this monsoon affected area, E. schimperi is found in two different habitat types: in continuous woodland belts in the Hawf and Dhofar mountains, and in isolated, scattered woodland patches in the Fartak Mountains. Ten populations (138 individuals) from across the southern Arabian distribution area of the species were analysed using chloroplast microsatellites and AFLP fingerprinting to a) reconstruct the phylogeographical pattern of E. schimperi on the southern Arabian Peninsula and b) to evaluate the consequences of population fragmentation on the genetic diversity harboured in isolated patches vs cohering stands. Phylogeographical reconstructions show that the distribution area of E. schimperi in the southern Arabian Peninsula is characterised by a geographical split that separates the southwestern populations (representated by material from Jabal Eraf and Jabal Uthmar), from the southcentral populations, which themselves are split from each other into a western (Ras Fartak) and an eastern refugium (Hawf/Dhofar). The analysis of the within-population genetic diversity in E. schimperi populations resulted in a slightly, but not significantly higher genetic variation in small and isolated woodland patches (HS=0.302) compared to larger, cohering stands (HS=0.291).  相似文献   

18.
Morphometric and meristic characteristics of a specimen of Grammicolepis brachiusculus Poey caught off the Algarve coast, southern Portugal, are reported. This is the first record of this benthopelagic species in Portuguese waters (including Madeira and Azores Archipelagos) and its fifth finding in the north-eastern Atlantic.  相似文献   

19.
The history of domestic sheep (Ovis aries) in Africa remains largely unknown. After being first introduced from the Near East, sheep gradually spread through the African continent with pastoral societies. The eastern part of Africa was important either for the first diffusion of sheep southward or for putative secondary introductions from the Arabian Peninsula or southern Asia. We analysed mitochondrial DNA control region sequences of 91 domestic sheep from Kenya and found a high diversity of matrilines from the widespread haplogroup B, whereas only a single individual from haplogroup A was detected. Our phylogeography analyses of more than 500 available mitochondrial DNA sequences also identified ancestral haplotypes that were probably first introduced in Africa and are now widely distributed. Moreover, we found no evidence of an admixture between East and West African sheep. The presence of shared haplotypes in eastern and ancient southern African sheep suggests the possible southward movement of sheep along the eastern part of Africa. Finally, we found no evidence of an extensive introduction of sheep from southern Asia into Africa via the Indian Ocean trade. The overall findings on the phylogeography of East African domestic sheep set the grounds for understanding the origin and subsequent movements of sheep in Africa. The richness of maternal lineages in Kenyan breeds is of prime importance for future conservation and breeding programmes.  相似文献   

20.
Archaeological survey undertaken in central Saudi Arabia has revealed 29 surface sites attributed to the Arabian Middle Paleolithic based on the presence of Levallois blank production methods. Technological analyses on cores retrieved from Al-Kharj 22 have revealed specific reduction modalities used to produce flakes with predetermined shapes. The identified modalities, which are anchored within the greater Levallois concept of core convexity preparation and exploitation, correspond with those utilized during the Middle Stone Age Nubian Complex of northeast Africa and southern Arabia. The discovery of Nubian technology at the Al-Kharj 22 site represents the first appearance of this blank production method in central Arabia. Here we demonstrate how a rigorous use of technological and taxonomic analysis may enable intra-regional comparisons across the Arabian Peninsula. The discovery of Al-Kharj 22 increases the complexity of the Arabian Middle Paleolithic archaeological record and suggests new dynamics of population movements between the southern and central regions of the Peninsula. This study also addresses the dichotomy within Nubian core typology (Types 1 and 2), which was originally defined for African assemblages.  相似文献   

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