When colour patterns reflect phylogeography: New species of Dasypeltis (Serpentes: Colubridae: Boigini) from West Africa

Six colour phases are currently known in the genus Dasypeltis in West Africa, three in the D. scabra complex and three in the D. fasciata complex. Molecular phylogenetic analysis reveals that all correspond to distinct species. D. parascabra sp. nov. is described from wet savannah areas of Guinea and Ivory Coast. D. latericia is given full specific rank. The validity of D. sahelensis, D. gansi and D. confusa – three species recently described on the basis of colour pattern and biogeography – is confirmed. D. fasciata is confined to rain forest areas of West and Central Africa. D. scabra is absent from West Africa.     

中国甘肃南部沟颈螺属一新种(柄眼目,艾纳螺总科)

描述了栖息于甘肃南部的陆生贝类艾纳螺科1新种,诺氏沟颈螺Holcauchen nordsiecki sp.nov..与各已知种相比,诺氏沟颈螺的体螺层和次体螺层最膨大;腔壁齿极弱;腭壁板齿阙如;腭壁凹陷极微弱;具上大下小2枚轴唇齿;在生殖系统中,鞭状器小;成荚器无盲囊;具纳精囊管分支盲管.诺氏沟颈螺,新种Holcauchen nordsiecki sp.nov.(图1～6)新种的鉴别特征:体螺层与次体螺层最膨大;腔壁齿极弱;无腭壁板齿;腭壁凹陷极微弱;轴唇齿2枚,上大下小.鞭状器小;成荚器无盲囊;纳精囊管具分支盲管.贝壳:螺层数6.25 ～ 6.88;壳高6.9 ～7.0 mm;壳径2.4～2.7 mm.正模,HBUMM06664-specimen 1,具软体部的成体;甘肃文县(33°05′N,104°21′E;海拔1 269m),2011-08-09;吴岷、徐沁、Prem B.Buhda采.副模,HBUMM06664-specimen 2～3,2头具软体部的成体;HBUMM06664-specimen 4,1枚成熟空壳;采集数据同正模.词源:新种种名源自德国贝类学家Hartmut Nordsieck的姓氏;名词.     

River hydrological seasonality influences life history strategies of tropical riverine fishes

Under a particular set of selective forces, specific combinations of traits (strategies) will be favored in a given population, within the particular constraints of the considered species. For fishes, three demographic strategies have been suggested to result from adaptive responses to environmental predictability (i.e., seasonality): periodic, opportunistic and equilibrium [Winemiller KO, Rose KA (1992) Patterns of life-history diversification in North American fishes: implications for population regulation. Can J Fish Aquat Sci 49:2196–2218]. These strategies optimize fitness within predictable, unpredictable and stable systems, respectively. We tested these predictions of life history trait distribution along a gradient of hydrologic seasonality in West African tropical rivers at the drainage basin scale. We used logistic regression of species presence–absence data to test whether dominant life history traits of species caused community compositional change in response to a gradient of seasonality in hydrologic regime across basins. After accounting for taxonomic relatedness, species body size and statistical redundancy inherent to related traits, we found a higher proportion of species producing a great number of small oocytes, reproducing within a short period of time and presenting a low degree of parental care (the periodic strategy) in highly seasonal drainage basins (e.g., rivers with a short and predictable favorable season). Conversely, in more stable drainage basins (e.g., rivers with a wet season of several months), we observed a greater proportion of species producing small numbers of large oocytes, reproducing within a long period of time and providing parental care to their offspring (the equilibrium strategy). Our results suggest that distributions of tropical freshwater fishes at the drainage basin scale can be partly explained by the match between life history strategies and seasonality gradients in hydrological conditions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Naturally Induced Humoral Immunity to West Nile Virus Infection in Raptors

West Nile virus (WNV) infection can be fatal to many bird species, including numerous raptors, though population- and ecosystem-level impacts following introduction of the virus to North America have been difficult to document. Raptors occupy a diverse array of habitats worldwide and are important to ecosystems for their role as opportunistic predators. We documented initial (primary) WNV infection and then regularly measured WNV-specific neutralizing antibody titers in 16 resident raptors of seven species, plus one turkey vulture. Most individuals were initially infected and seroconverted between July and September of 2003, though three birds remained seronegative until summer 2006. Many of these birds became clinically ill upon primary infection, with clinical signs ranging from loss of appetite to moderate neurological disease. Naturally induced WNV neutralizing antibody titers remained essentially unchanged in some birds, while eight individuals experienced secondary rises in titer presumably due to additional exposures at 1, 2, or 3 years following primary infection. No birds experienced clinical signs surrounding or following the time of secondary exposure, and therefore antibodies were considered protective. Results of this study have implications for transmission dynamics of WNV and health of raptor populations, as well as the interpretation of serologic data from free-ranging and captive birds. Antibodies in raptors surviving WNV may persist for multiple years and protect against potential adverse effects of subsequent exposures.     

Herbarium collections and field data-based plant diversity maps for Burkina Faso

A map of plant species diversity in Burkina Faso is presented based on field observations and specimen data from the Ouagadougou University Herbarium (OUA) and the Herbarium Senckenbergianum (FR). A map of collecting intensity and field observations illustrates centres of botanical research activities in Burkina Faso. To overcome problems associated with biased sampling intensity, distributions of species have been modelled and extrapolated to maps of vascular plant diversity, life forms and diversity of four selected families (Poaceae, Cyperaceae, Dioscoreaceae and Rubiaceae). The area of most intensive collection and observation is around Gorom‐Gorom and Fada N’Gourma. Modelled diversity generally increases towards the south, as does the proportion of phanerophytes, lianas and hemicryptophytes, while the opposite trend is observed for therophytes. Poaceae diversity is highly correlated with total vascular plant diversity, making the family especially suitable as an indicator for overall plant diversity. Cyperaceae are rather evenly distributed throughout the country, Dioscoreaceae are restricted to the Sudanian Zone. Rubiaceae have their highest diversities in the very south. Our approach can be transferred to areas with a similar database, certainly to other areas within West Africa. Future research should focus on distribution data for rare species, enabling our approach to evaluate the West African system of protected areas.     

Heavy Metals in Sediments of the Gold Mining Impacted Pra River Basin,Ghana, West Africa

Total concentrations of Hg, Al, Fe, As, Pb, Cu, Cr, Ni, Mn, Co, V, and Zn were determined in surface sediments collected from 21 locations within the gold mining impacted Pra River basin in southwestern Ghana. Samples were collected during both the rainy and dry seasons. We hypothesized that in the rural southwestern portion of Ghana, the lack of industrial activities makes artisanal gold mining (AGM) by Hg amalgamation the main source of water resource contamination with heavy metals. Therefore, metals showing concentration trends similar to that of Hg in the studied system are likely impacted by AGM. We found that total-Hg (THg) concentrations in riverine sediments are rather low as compared to other aquatic systems that are impacted by similar mining activities. Measured THg concentrations ranged from 0.018 to 2.917 mg/kg in samples collected in the rainy season and from about 0.01 to 0.043 mg/kg in those collected during the dry season. However, the determination of the enrichment factor (EF) calculated using shale data as reference background values showed signs of severe contamination in most of the sampled sites. In the dry season, THg concentrations correlated positively and significantly to the concentrations of As (r = 0.864, p < 0.01), Cu (r = 0.691, p < 0.05), and Ni (r = 0.579, p < 0.05). Based on our previously stated hypothesis, this could then be an indication of the impact of AGM on ambient levels of these 3 elements. However, the determined concentrations of Cu, and Ni co-varied significantly with Al, suggesting that natural sources do account for the observed levels. Accordingly, both AGM and metal inputs from weathered natural deposits are likely co-responsible for the observed levels of Cu and Ni. In contrast, the lack of correlation between As and Al tends to suggest an impact of AGM on As levels. Overall, our data suggest that besides Hg and to some extent As, the impact of AGM on ambient levels of investigated metals in the gold mining impacted Pra River remains negligible. Finally, the increase in metal concentrations from the dry to the rainy season underlines the impact of changes in hydrologic conditions on levels and fate of metals in this tropical aquatic system.     

Microsatellite loci from the northern house mosquito (Culex pipiens), a principal vector of West Nile virus in North America

Microsatellites were isolated and characterized in the northern house mosquito, Culex pipiens, a widespread pest species and important vector of diseases such as West Nile virus. An enrichment protocol yielded 150 positive clones. We designed primers to amplify 17 unique (GT)_n microsatellites, eight of which amplified cleanly and were polymorphic. A survey of 29 individuals showed that these loci are highly variable with the number of alleles ranging from seven to 19 and expected heterozygosity ranging from 0.66 to 0.93. These markers will be useful for studies of population structure and intraspecific variation in epidemiological characteristics of Cx. pipiens.     

西北干旱荒漠区种子植物科的区系分析

西北干旱荒漠区分布有种子植物82科、484属、1704种,优势现象明显,优势科11个,它们是菊科、豆科、禾本科、藜科,十字花科、蓼科,莎草科、毛莨科、蔷薇科、唇形科和百合科;表征科8个,它们是香蒲科,麻黄科,柽柳科、蒺藜科,胡颓子科、藜科、眼子菜科和蓼科。地理成分多样,其中以世界广布成分为主,共37科,占总科数的45.12%,其次为温带成分（包括热带至温带,亚热带至温带,温带,温带至寒带）,共有31科,占总科数的37.80%,热带成分,热带致亚热带成分较少,共14科,占总科数的17.07%。这些反映出植物的分布与本地区气候相适应的特点。     

高黎贡山自然保护区西坡垂直带蚂蚁群落研究

首次研究了高黎贡山自然保护区西坡垂直带蚂蚁群落及共物种多样性。在北段和中北段随海拔升高优势种数目增加,而在南段随海拔升高优势种数目递减。在北段和中北段海随海拔升高优势种所占百分比递减,而在南段随海拔升高优势种所占比例递增。在西坡４个地段均呈现随海拔升高种数目和密度递减的基本规律。北段和中北段随海拔升高优势度指数降低,中南段和南段随海拔升高优势度指数增大。北段随海拔升高多样性指数递增,中北段多样性指数缺乏规律性,中南段和南段随海拔升高多样性指数递减。北段、中北段和中南段均呈现随海拔升高无效度指数递增规律,而南段表现出随海拔升高均匀度指数递减的相反情况。西坡４个地段垂直带上,蚂蚁群落之间的相似系数几乎均在０．００－０．２５,处于极不相似水平,只有１个系数超过此范围,我们认为在原始植被状态下,高黎贡山自然保护区西坡蚂蚁群落的基本规律是随着海拔升高。优势种数目递减,优势种所占比 递增,物种数目递减,优势度指数递增,多样性指数递减,均匀度指数递减。山体中部和下部植被的毁坏导致了实际调查中出现的反常情况。