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1.
PLoS One ; 19(5): e0302435, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38753816

RESUMEN

Laetoli, Tanzania is one of the most important palaeontological and palaeoanthropological localities in Africa. We report on a survey of the extant terrestrial gastropod faunas of the Laetoli-Endulen area, examine their ecological associations and re-examine the utility of Pliocene fossil molluscs in palaeoenvironmental reconstruction. Standardised collecting at 15 sites yielded 7302 individuals representing 58 mollusc species. Significant dissimilarities were found among the faunas of three broad habitat types: forest, woodland/bushland and open (grassland and scattered, xeric shrubland). Overall, more species were recorded in the woodland/bushland sites than in the forest sites. Open sites were less diverse. Environmental factors contributing most strongly to the separation of habitat types were aridity index and elevation. The results are supplemented with new mollusc data from the Mbulu Plateau south of Lake Eyasi, and compared to the list of species cumulatively recorded from the Ngorongoro area. Some regional variation is apparent and historical factors may explain the absence of some fossil taxa from Laetoli today. Differences in seasonality separated upland forest sites on the Mbulu plateau from those at Lemagurut at Laetoli. Indicator species were identified for each habitat. These included several large-bodied species analogous to the Laetoli Pliocene fossil species that were then used for palaeoenvironmental reconstruction. Based on the estimated aridity index, and adopting the widely used United Nations Environment Programme (UNEP) global climate classification, the four stratigraphic subunits of the Upper Laetolil Beds (3.6-3.85 Ma) would be placed in either the UNEP's Dry Sub-humid or Semi-arid climate classes, whereas the Upper Ndolanya Beds (2.66 Ma) and Lower Laetolil Beds (3.85-<4.36 Ma) would be assigned to the Humid and Semi-arid climate classes respectively. Pliocene precipitation at Laetoli is estimated as 847-965 mm per year, refining previous estimates. This is close or slightly higher than the present mean annual precipitation, and is likely to have corresponded to a mosaic of forest, woodland and bushland within a grassland matrix consistent with other reconstructions.


Asunto(s)
Clima , Ecosistema , Fósiles , Paleontología , Animales , Tanzanía , Hominidae/fisiología , Moluscos/clasificación , Moluscos/fisiología , Biodiversidad
2.
Animals (Basel) ; 10(8)2020 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32823900

RESUMEN

The Western European Hedgehog (Erinaceous europaeus) is a nocturnal animal that is in decline in much of Europe, but the monitoring of this species is subjective, prone to error, and an inadequate basis for estimating population trends. Here, we report the use of Crenosoma striatum, a parasitic nematode specific to hedgehogs as definitive hosts, to detect hedgehog presence in the natural environment. This is achieved through collecting and sampling the parasites within their intermediate hosts, gastropoda, a group much simpler to locate and sample in both urban and rural habitats. C. striatum and Crenosoma vulpis were collected post-mortem from the lungs of hedgehogs and foxes, respectively. Slugs were collected in two sessions, during spring and autumn, from Skomer Island (n = 21), which is known to be free of hedgehogs (and foxes); and Pennard, Swansea (n = 42), known to have a healthy hedgehog population. The second internal transcribed spacer of parasite ribosomal DNA was used to develop a highly specific, novel, PCR based multiplex assay. Crenosoma striatum was found only at the site known to be inhabited by hedgehogs, at an average prevalence in gastropods of 10% in spring and autumn. The molecular test was highly specific: One mollusc was positive for both C. striatum and C. vulpis, and differentiation between the two nematode species was clear. This study demonstrates proof of principle for using detection of specific parasite DNA in easily sampled intermediate hosts to confirm the presence of an elusive nocturnal definitive host species. The approach has great potential as an adaptable, objective tool to supplement and support existing ecological survey methods.

3.
Nat Commun ; 9(1): 2242, 2018 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-29872049

RESUMEN

The originally published version of this Article contained an error in Fig. 3, whereby an additional unrelated graph was overlaid on top of the magnetic susceptibility plot. Furthermore, the Article title contained an error in the capitalisation of 'Stone Age'. Both of these errors have now been corrected in both the PDF and HTML versions of the Article.

4.
Nat Commun ; 9(1): 1832, 2018 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-29743572

RESUMEN

The Middle to Later Stone Age transition in Africa has been debated as a significant shift in human technological, cultural, and cognitive evolution. However, the majority of research on this transition is currently focused on southern Africa due to a lack of long-term, stratified sites across much of the African continent. Here, we report a 78,000-year-long archeological record from Panga ya Saidi, a cave in the humid coastal forest of Kenya. Following a shift in toolkits ~67,000 years ago, novel symbolic and technological behaviors assemble in a non-unilinear manner. Against a backdrop of a persistent tropical forest-grassland ecotone, localized innovations better characterize the Late Pleistocene of this part of East Africa than alternative emphases on dramatic revolutions or migrations.

5.
Zookeys ; (723): 11-42, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29362525

RESUMEN

New and little-known terrestrial slugs are dealt with based on extensive collections made in East Africa (Kenya, Tanzania, and Uganda) 1993-2007. This account deals primarily with larger species from forests in the Eastern Arc Mountains of Tanzania. In Veronicellidae, Pseudoveronicella Germain, 1908 is extended to Tanzania by P. (Hoffmannia) zootoca tanzaniensis subsp. n. in the Udzungwa Mts. In Urocyclidae, Dendrolimax parensissp. n. is described from the Pare Mts. and Leptichnoides avisexcrementissp. n. is described from the Uluguru Mts. In Urocyclinae, Tanzalimax tattersfieldigen. & sp. n. is described from the Usambara Mts., Tanzalimax seddonaegen. & sp. n. from the Uluguru Mts., and Udzungwalimax suminisgen. & sp. n. from the Udzungwa Mts. In addition, the ill-defined genus Atrichotoxon Simroth, 1910 is discussed and the little-known Dendrolimax leprosus Pollonera, 1906 is reported from Uganda. In Agriolimacidae, a species of Deroceras Rafinesque, 1820 is reported for the first time from southern Tanzania. The taxonomic attribution and significance of each discovery is discussed.

6.
Zookeys ; (589): 23-53, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27408533

RESUMEN

The family Streptaxidae in Laos is revised. Twelve species are known, mainly from limestone areas, in the genera Discartemon Pfeiffer, 1856, Perrottetia Kobelt, 1905, Haploptychius Möllendorff, 1906, and Indoartemon Forcart, 1946. Three new species, Perrottetia unidentata sp. n. and Perrottetia megadentata sp. n. from northern and central Laos, and Indoartemon diodonta sp. n. from central Laos, are described. All eight species of these three genera previously recorded from Laos are revised and discussed based on examined material from Laos, Cambodia, Vietnam and Thailand. Type material was examined and lectotypes are designated. Details of genital anatomy and radulae are provided, including the first detailed genitalia and radula descriptions from Haploptychius. Two novelties in Streptaxidae, a vaginal caecum, and the occurrence of aphallic individuals, are reported from Haploptychius pellucens (Pfeiffer, 1863).

7.
Parasit Vectors ; 9: 56, 2016 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-26830203

RESUMEN

BACKGROUND: Angiostrongylus vasorum is a highly pathogenic metastrongylid nematode affecting dogs, which uses gastropod molluscs as intermediate hosts. The geographical distribution of the parasite appears to be heterogeneous or patchy and understanding of the factors underlying this heterogeneity is limited. In this study, we compared the species of gastropod present and the prevalence of A. vasorum along a rural-urban gradient in two cities in the south-west United Kingdom. METHODS: The study was conducted in Swansea in south Wales (a known endemic hotspot for A. vasorum) and Bristol in south-west England (where reported cases are rare). In each location, slugs were sampled from nine sites across three broad habitat types (urban, suburban and rural). A total of 180 slugs were collected in Swansea in autumn 2012 and 338 in Bristol in summer 2014. A 10 mg sample of foot tissue was tested for the presence of A. vasorum by amplification of the second internal transcribed spacer (ITS-2) using a previously validated real-time PCR assay. RESULTS: There was a significant difference in the prevalence of A. vasorum in slugs between cities: 29.4% in Swansea and 0.3% in Bristol. In Swansea, prevalence was higher in suburban than in rural and urban areas. Comparing the sampled slug fauna, Arion rufus was found in greater numbers in Swansea than Bristol, and was commonly infected (prevalence 41%). This, alongside the timing of slug collections in summer rather than autumn, could explain low infection prevalence in the Bristol sample. In the absence of Ar. rufus as a preferred host for A. vasorum, Ar. flagellus and Limacus maculatus appear to act as versatile hosts that are present in suburban and urban areas in Swansea (prevalence in Ar. flagellus 33%; in L. maculatus 44%) and in Bristol (prevalence in Ar. flagellus 0.9%). These slug species might provide A. vasorum with an alternative vehicle to reach the final host, when the main host Ar. rufus is scarce or absent. CONCLUSION: We conclude that the composition of the slug fauna varies spatially, and that this could help explain patchiness in the prevalence of A. vasorum. A suburban peak was found in the prevalence of infection in intermediate hosts, perhaps explained by a higher density of competent intermediate and/or definitive hosts.


Asunto(s)
Angiostrongylus/aislamiento & purificación , Gastrópodos/parasitología , Animales , Ciudades/epidemiología , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Geografía , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Reino Unido/epidemiología
8.
PLoS One ; 9(4): e91907, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24740519

RESUMEN

The slugs of Britain and Ireland form a well-studied fauna of economic importance. They include many widespread European species that are introduced elsewhere (at least half of the 36 currently recorded British species are established in North America, for example). To test the contention that the British and Irish fauna consists of 36 species, and to verify the identity of each, a species delimitation study was conducted based on a geographically wide survey. Comparisons between mitochondrial DNA (COI, 16S), nuclear DNA (ITS-1) and morphology were investigated with reference to interspecific hybridisation. Species delimitation of the fauna produced a primary species hypothesis of 47 putative species. This was refined to a secondary species hypothesis of 44 species by integration with morphological and other data. Thirty six of these correspond to the known fauna (two species in Arion subgenus Carinarion were scarcely distinct and Arion (Mesarion) subfuscus consisted of two near-cryptic species). However, by the same criteria a further eight previously undetected species (22% of the fauna) are established in Britain and/or Ireland. Although overlooked, none are strictly morphologically cryptic, and some appear previously undescribed. Most of the additional species are probably accidentally introduced, and several are already widespread in Britain and Ireland (and thus perhaps elsewhere). At least three may be plant pests. Some evidence was found for interspecific hybridisation among the large Arion species (although not involving A. flagellus) and more unexpectedly in species pairs in Deroceras (Agriolimacidae) and Limacus (Limacidae). In the latter groups, introgression appears to have occurred in one direction only, with recently-invading lineages becoming common at the expense of long-established or native ones. The results show how even a well-studied, macroscopic fauna can be vulnerable to cryptic and undetected invasions and changes.


Asunto(s)
Gastrópodos/genética , Animales , Biodiversidad , Gastrópodos/anatomía & histología , Variación Genética , Haplotipos , Irlanda , Filogenia , Especificidad de la Especie , Reino Unido
9.
Zookeys ; (401): 45-107, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24843260

RESUMEN

Twelve new species of the streptaxid snail genus Discartemon Pfeiffer, 1856 are described from southern Thailand and western Malaysia, D. afthonodontia sp. n., D. circulus sp. n., D. deprima sp. n., D. discadentus sp. n., D. discamaximus sp. n., D. expandus sp. n., D. flavacandida sp. n., D. kotanensis sp. n., and D. megalostraka sp. n. from southern Thailand, as well as D. conicus sp. n., D. epipedis sp. n. and D. triancus sp. n. from western Malaysia. All 15 previously described species are revised and commented upon based on examined material. Streptaxis paradiscus Möllendorff, 1900 is considered a junior subjective synonym of the type species D. discus (Pfeiffer, 1853). Details of the genital anatomy of twelve species, and the radula and pallial system, are provided for the first time. An identification key is provided.

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