水位波动对南美蟛蜞菊和蟛蜞菊种内及种间关系的影响

以外来入侵植物南美蟛蜞菊和本地近缘种蟛蜞菊为对象,通过温室模拟3种水位波动模式(水位无波动,水位波动模式分别为15 cm-0 cm-15 cm和0 cm-15 cm-0 cm)交叉5种定植模式(试验容器内分别为入侵种单株、本土种单株、入侵种6株、本土种6株以及2物种各3株混种)的试验,研究水位波动对入侵植物和本地近缘种生长繁殖性状及种内种间相互作用的影响.结果表明: 水位波动显著降低了南美蟛蜞菊和蟛蜞菊的总生物量、茎生物量、叶生物量、根生物量、茎长、节点数、叶片数及叶面积,对南美蟛蜞菊和蟛蜞菊种内及种间竞争系数的影响均显著.水位波动改变了南美蟛蜞菊的种内和种间竞争关系,说明入侵植物南美蟛蜞菊对水位波动更为敏感,对环境改变表现出更强的适应性.     

有害植物孪花蟛蜞菊扩张对西沙岛屿陆生软体动物的影响

有害植物孪花蟛蜞菊(Wedelia biflora)的扩张对我国西沙群岛原生植物群落结构和功能产生了深刻影响, 但陆生软体动物如何响应该扩张却未见报道。本文调查了西沙群岛永兴岛孪花蟛蜞菊不同扩张程度下褐云玛瑙螺(Achatina fulica)、钻头螺科、坚齿螺科和拟阿勇蛞蝓科等主要陆生软体动物的残体分布情况, 测定了残体的分布密度和壳高、壳宽、壳重等可量化性状指标, 研究了孪花蟛蜞菊扩张对陆生软体动物种群的影响。结果表明: (1)随孪花蟛蜞菊扩张程度增加, 钻头螺科和褐云玛瑙螺的种群密度增加, 坚齿螺科种群密度减小, 拟阿勇蛞蝓科种群密度出现先增加后减少的趋势; (2)陆生软体动物类群的体型分布频率随孪花蟛蜞菊扩张呈现不同的变化趋势, 褐云玛瑙螺较小个体数量增加, 其他陆生软体动物体型分布变化不明显或较大体型残体分布增加; (3)孪花蟛蜞菊扩张对褐云玛瑙螺体型特征产生抑制作用, 褐云玛瑙螺主要采用r策略来响应有害植物扩张的影响。综上, 有害植物孪花蟛蜞菊在热带珊瑚岛屿植被中的扩张改变了陆生软体动物的形态、密度与种群结构, 不同的软体生物类群表现出不同响应策略, 在海岛有害生物的综合防治过程中应该引起足够重视。     

Effects of habitat-conditioning by the damselfish Stegastes nigricans (Lacepède) on the community structure of benthic algae

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained “algae farms” that were dominated by the filamentous rhodophyte, Womersleyella setacea. Species richness and biomass were higher inside damselfish territories than outside, while species diversity and evenness were higher outside. Detrended correspondence analysis (DCA) based on species composition showed that the dominance of W. setacea was maintained throughout the year in all samples collected from inside damselfish territories. The observed strong dominance of filamentous rhodophytes was consistent with the findings of most studies on damselfish territories worldwide. However, the dominance of a single species of alga and low species diversity inside the territories was in contrast to the findings of previous studies, in which the reduction of grazing pressure caused intermediate disturbance and enhanced algal species diversity. This discrepancy in algal species diversity inside the damselfish territories seems to have been caused by unique characteristics of the alga and the fish. W. setacea traps sediment, which reduces the availability of firm substrata for attachment and inhibits the recruitment of some algae. Moreover, S. nigricans “weeds” indigestible calcareous and thicker algae. The algal assemblage outside damselfish territories varied among samples, and included mat-forming cyanophytes (Calothrix aeruginosa and Calothrix codicola), a prostrate laminar phaeophyte (Padina sp.), thin and small-scaled algae (Cladophora sp. and Feldmannia indica), finely branched filamentous rhodophytes (Taenioma perpusillum and Herposiphonia obscura), and a coarsely branched rhodophyte (Gelidiopsis variabilis).

We placed artificial slate plates inside and outside damselfish territories, and showed that the W. setacea inside territories gradually increased in biomass, reaching the same levels of biomass and dominance as W. setacea on natural substrata. Outside the territories, the algal assemblage underwent succession from early colonizers, i.e., thin and small-scaled algae, to grazing-resistant algae such as mat-forming cyanophytes and prostrate laminar Padina sp. Under heavy grazing, the flora outside the territories was composed of early colonizers, grazing-resistant algae, and scattered erect algae that had probably escaped grazing by chance.

Our findings suggest that sediment trapped by the turf of W. setacea inhibited recruitment of some algae, and that moderate cropping and selective weeding by S. nigricans excluded grazing-resistant algae and prevented early colonizers and competitively superior algae from out-competing W. setacea. Consequently, low species diversity and a high-biomass “farm” suitable for harvesting was maintained.     

Early Cretaceous (Valanginian - Hauterivian) calcareous nannofossils and isotopes of the northern hemisphere: proxies for the understanding of Cretaceous climate

From three boreholes (DSDP Site 535; ODP Site 638; BGS borehole 81/43) of the Central Atlantic and the North Sea Basin 379 samples of early Cretaceous age (Valanginian-Hauterivian) were examined. The localities cover a S-N transect of approximately 3000 km stretching from 17°N to 40°N palaeolatitude. The distribution of calcareous nannofossils and fluctuations of the stable isotopes (δ¹³C, δ¹⁸O) have been recorded and were compared with results of recent studies. We differentiate between high nutrient indicators and oligotrophic taxa and propose a four step scheme to characterize the trophic level of the surface water. (1) High abundances of the fertility group (Biscutum constans/Zeugrhabdotus spp.) combined with a high dominance of B. constans and low abundances of Watznaueria barnesae/W. fossacincta represent a high nutrient environment (eutrophic setting). (2) High abundances of the fertility group combined with a high dominance of Zeugrhabdotus spp. and low abundances of W. barnesae/W. fossacincta reflect enhanced nutrient contents of the surface water (mesotrophic setting). (3) Enhanced abundances of the fertility group combined with high abundances of W. barnesae/W. fossacincta indicate slightly increased nutrient contents of the surface water (meso- to oligotrophic setting). (4) Low abundances of the fertility group and high abundances of W. barnesae/W. fossacincta are of low nutrient affinities (oligotrophic setting). Our estimations of seawater palaeotemperatures in combination with literature data show a distinctive trend for the Valanginian to Hauterivian interval. A general decrease of water temperature from the Valanginian to the early Hauterivian is obvious. This decrease of temperature coincides with the southward migration of the high latitudinal cold water species Crucibiscutum salebrosum to lower latitudes. Our findings shed new light on the evolution of the earliest Cretaceous climate, which may be characterized as a warm greenhouse world with interludes of short cooling.     

A direct fluorescence technique for the rapid detection of sheathed microfilariae in blood smears

Thick and thin blood smears containing microfilariae of Wuchereria bancrofti, Loa loa, Brugia malayi, Brugia pahangi, Brugia patei or Acanthocheilonema vileae were prepared from either cryopreserved blood samples or from freshly collected blood, fixed in methanoi and treated with a fluoresceinated lectin wheat germ agglutinin. Sheathed microfilariae of W. bancrofti, L. loa, B. malayi, B. pahangi and B. patei in the blood smears could be easily detected and counted using a fluorescence assay. The unsheathed microfilaria of Acanthocheilonema viteae did not fluoresce. The possibility of adapting this technique, which does not require the use of parasite specific antibody for the sensitive, parasitological detection offilarial infections, is discussed.     

Wuacanthus (Acanthaceae), a new Chinese endemic genus segregated from Justicia (Acanthaceae)

A new genus, Wuacanthus Y.F. Deng, N.H. Xia & H. Peng (Acanthaceae), is described from the Hengduan Mountains, China. Wuacanthus is based on Wuacanthus microdontus (W.W.Sm.) Y.F. Deng, N.H. Xia & H. Peng, originally published in Justicia and then moved to Mananthes. The new genus is characterized by its shrub habit, strongly 2-lipped corolla, the 2-lobed upper lip, 3-lobed lower lip, 2 stamens, bithecous anthers, parallel thecae with two spurs at the base, 2 ovules in each locule, and the 4-seeded capsule. Phylogenetic analyses show that the new genus belongs to the Pseuderanthemum lineage in tribe Justicieae. Wuacanthus is closely related to Pseuderanthemum but differs from the latter by its shorter corolla tube and two minute spurs at the base of each anther-theca. W. microdontus is assessed with the status EN B2ab (iii) based on the IUCN Red List Categories and Criteria.     

Territorial damselfish enhances multi-species co-existence of foraminifera mediated by biotic habitat structuring

The structures of benthic foraminiferal communities inside and outside the territory of the pomacentrid damselfish Stegastes nigricans on coral rocks in a moat of Sesoko Is. (26°38′N, 127°52′E) in Okinawa, Japan were compared. Inside the territory, an algal farm, i.e., a dense stand of a filamentous rhodophyte, Womersleyella setacea, was maintained throughout the year. Outside the territory, in areas subjected to intensive and continuous grazing by various grazers, the flora was composed of mat-like cyanophytes, a prostrate turf-form Padina sp., microscopically thin filaments and scattered filamentous rhodophytes. Algal biomass was greater inside the territory than outside the territory of the damselfish. These differences were reflected by the structure of the associated foraminiferal communities. We classified foraminiferal species based on their microhabitat use around algal communities into four life types: free-living type, crawling type, sedentary type, and sessile type. The abundance of foraminifera, especially the free-living type (e.g., Peneroplis pertusus and Quinqueloculina seminulum) and sedentary type (Rosalina globularis and Cymbaloporetta squammosa), was greater inside the territory of the damselfish than outside the territory. Species richness was also higher inside the territory, mainly due to an increase in species richness of the free-living and sedentary types. These increases in abundance and species richness were caused by habitat structuring. W. setacea is a relatively tall and complicated alga with tangled rhizoids. Its dense stand inside the territory trapped a larger amount of sediment, which provided free-living foraminifera with heterogeneous and stable habitats. In addition, the dense stand of W. setacea provided sedentary-type foraminifera with a large, complex substratum, providing refuge and food inside the territory. This assumption was confirmed by the results of plate experiments showing that foraminiferal community structures were controlled by associations between foraminifera and algae. We showed that habitat-conditioning is an important process in biotic habitat-structuring and that habitat-conditioning by territorial damselfish maintains and enhances multi-species coexistence of foraminifera on coral rocks in a coral reef.     

东江外来齐氏罗非鱼个体繁殖力初步研究

于2011年1月至2011年12月,逐月在东江采集齐氏罗非鱼样本, 研究其个体繁殖力。结果表明, 齐氏罗非鱼属于多次产卵类型, 在东江的繁殖期约为5月初到10月底。个体绝对繁殖力(F)在4913~13129粒之间, 平均为7991粒;一次产卵量(F_b)在1997~6369粒之间, 平均为4114粒;体长相对繁殖力(F_L)在49~83粒/mm之间, 平均为62粒/mm;体质量相对繁殖力(F_W)在66~154粒/g之间, 平均为98粒/g。个体绝对繁殖力及一次产卵量与体长(L)呈幂函数相关, 与体质量(W)及净体质量(W_n)呈线性相关。相关回归式分别为:F=2.186L^1.6886 ;F_b =0.7243L^1.7796;F=50.184W + 3627.3;F_b=25.008W + 1952.2;F=58.783 W_n + 3553.4, F_b=28.939 W_n +1942。     

长江上游特有种长鳍吻鮈种群数量和资源利用评估

长鳍吻鮈(Rhinogobio ventralis)为长江上游特有种, 由于过度捕捞和大坝建设, 其种群生存受到极大威胁。为了解三峡工程蓄水后、金沙江一期工程蓄水前该物种的种群动态, 作者利用2007-2009年长江上游江津和宜宾江段调查获取的体长频率数据, 评估了其生长和死亡参数、种群数量及资源利用情况。结果表明, 长江上游长鳍吻鮈渔获群体体长范围为52-250 mm, 体重范围为2.7-307.2 g, 平均体长为150.8 ± 40.7 mm, 平均体重为72.3 ± 49.7 g。江津江段长鳍吻鮈平均体长(168.6 ± 29.5 mm)显著大于宜宾江段(125.6 ± 41.2 mm)。长鳍吻鮈体长-体重关系为: W = 6.06 × 10^-6L^3.20 (R² = 0.98, P < 0.01, n = 436)。由体长频率法拟合出渐近体长(L_∞)为338 mm, 生长系数(k)为0.24/yr。由Pauly公式、Gunderson和Dygert公式、Jensen公式等3种方法估算出其平均自然死亡系数为0.43。由长度转渔获物曲线估算出江津和宜宾江段长鳍吻鮈的总死亡系数分别为2.26和2.09。江津和宜宾江段长鳍吻鮈资源开发率分别为0.81和0.79, 已超过由Beverton-Holt动态综合模型估算出的最大开发率0.57和0.62。由体长实际种群分析估算出2007、2008和2009年江津江段长鳍吻鮈种群数量分别为68,247、67,432和176,266尾, 平均为103,982尾; 宜宾江段种群数量分别为22,953尾、46,340尾和34,021尾, 平均为34,438尾, 表明江津江段种群数量高于宜宾江段。长鳍吻鮈资源已被过度开发, 建议加强种群动态监测, 延长禁渔期及开展栖息地修复等措施保护这一特有物种。     

Structures of the galactomannans from seeds of Annona muricata, Arenga saccharifera, Cocos nucifera, Convolvulus tricolor, and Sophora japonica

Galactomannans were isolated from ripe seeds of Annona muricata (Annonaceae), Convolvulus tricolor (Convolvulaceae), Sophora japonica (Leguminosae), and from immature seeds of Arenga saccharifera and Cocos nucifera (both Palmae). Their sugar compositions were determined and their structures studied by the methylation and periodate-oxidation techniques. All the galactomannans studied are of the leguminous type, the molecules having main chains consisting of (1→4)-linked β- -mannose residues, with differing proportions of side chains consisting of single - -galactose residues linked to the main chains by (1→6)-bonds. The molecular weights were found to vary from 6,000 (Sophora) to 17,000 (Arenga). The isolation of the galactomannan of Annona is the first recorded occurrence of this type of polysaccharide in the family Annonaceae, whereas there has been a previous report of the occurrence of a galactomannan in the Convolvulaceae; the study of the structure of the Sophora galactomannan is the first one in the tribe Sophoreae of the Leguminosae.     

Expression patterns of hedgehog, wingless, and decapentaplegic during gut formation of Gryllus bimaculatus (cricket).

We observed expression patterns of hedgehog (hh), wingless (wg), and decapentaplegic (dpp) during gut development of Gryllus bimaculatus (the cricket), a typical hemimetabolous insect, and compared with those observed in Drosophila, a typical holometabolous insect. Gryllus hh(Gbhh) and Gbwg are expressed in both foregut and hindgut, while Gbdpp is expressed only in the hindgut: at the boundaries between the small and large intestine, and between the large intestine and rectum. Although the expression patterns of Gbhh and Gbwg are essentially comparable to those observed in Drosophila, the expression pattern of Gbdpp differs from those of the Drosophila dpp.     

Megaspores from the Late Permian, Lower Whybrow coal seam, Sydney Basin, Australia

More than 300 megaspore specimens have been recovered from samples from the Late Permian, Lower Whybrow coal seam of the Wittingham Coal Measures of the Sydney Basin. Only two species are recognised: Singhisporites surangei (Singh) Potonié, emend. and a new species of Singhisporites. Species distribution within the seam is controlled by a major fire event, as recognised by coal petrology and mesofossil content: Singhisporites surangei is dominant before the event, but following it, it is subordinate to the new species.

The abundance of megaspores recovered has allowed recognition of the full range of morphologic variation of Singhisporites surangei, which encompasses specimens assigned previously to Singraulispora Pant & Mishra, 1986 and Mammilaespora Pant & Srivastava, 1961; both are regarded as junior synonyms of Singhisporites Potonié, emend. Ultrastructurally, the new species shows affinities with Mesozoic isoetalean megaspores.     

The electrochemical proton potential and the proton/electron ratio of the electron transport with fumarate in Wolinella succinogenes

The electrochemical proton potential across the cytoplasmic membrane ( ) as well as the H⁺ / e ratio, which were brought about by the electron transport of Wolinella succinogenes, was measured with the aim of understanding the mechanism of electron-transport-coupled phosphorylation in this anaerobic bacterium. (1) Inverted vesicles derived from the bacterial membrane were found to take up protons from the external medium on initiation of fumarate reduction by H₂. Proton uptake was dependent on the presence of K⁺ within the vesicles, was enhanced by the presence of valinomycin and DCCD and high internal buffer concentration, and was abolished by protonophores. The maximum H⁺ / e ratio slightly exceeded 1. (2) The vesicles accumulated thiocyanate in the steady state of fumarate reduction by H₂. The concentration ratio (internal / external) was close to 1000 at an external thiocyanate concentration below 10 μM. Under the same conditions the uptake of methylamine was negligible. Thiocyanate uptake was abolished by the presence of a protonophore. (3) Cells of W. succinogenes accumulated tetraphenylphosphonium cation (TPP) in the steady state of fumarate reduction with H₂ or formate. Under the same conditions the uptake of benzoic acid was negligible. From the amount of TPP taken up by the bacteria, the free internal concentration of TPP was evaluated according to the procedure of Zaritsky et al. (Zaritsky, A., Kihara, M. and MacNab, R.M. (1981) J. Membrane Biol. 63, 215–231). The concentration ratio (internal / external) was 700 in the absence and close to 1 in the presence of a protonophore or in the absence of external Na⁺. (4) The experimental results are consistent with the view that the energy transduction from electron transport to phosphorylation is done by means of the across the bacterial membrane.     

A contribution to Gymnosphaera (Cyatheaceae) in mainland Asia: Two new species,reinstatement of Cyathea bonii,and their phylogenetic positions

Gymnosphaera represents a minor lineage within the scaly tree-fern family Cyatheaceae. Tropical and subtropical mainland Asia is a main distribution area of Gymnosphaera. However, the species diversity of Gymnosphaera is currently incompletely known in mainland Asia due to lacking critical revision. Here we present new findings of species diversity and their relationships to mainland Asian Gymnosphaera based on field surveys, the examination of herbarium collections, and phylogenetic analyses of sequences of multiple chloroplast and nuclear regions. Two new species, G. saxicola from southwestern Yunnan and G. bachmaensis from central Vietnam, are established. Traditionally recognized G. podophylla is revealed to be a complex, from which G. bonii is reinstated as a distinct species. Our phylogenetic analyses identified four clades within Gymnosphaera in mainland Asia: G. denticulata clade, G. gigantea clade, G. podophylla clade, and G. salletii clade. The new species G. saxicola, which is special for its saxicolous habitat, was resolved as sister to G. austroyunnanensis in the G. salletii clade. The newly discovered G. bachmaensis, which is characterized specially by the spathulate frond, was positioned in the G. podophylla clade, being sister to G. bonii. The mountainous region from south-central Vietnam northwards to western Yunnan is a diverse center of Gymnosphaera and more species of this group are probably to be discovered there.     

中国甘肃省狭义丝盖伞属二新种

依据形态学和分子系统学研究结果,描述了产自中国甘肃省的狭义丝盖伞属2个新种,即拟黄囊丝盖伞Inocybe muricellatoides和甘肃丝盖伞I. gansuensis。对新种的ITS、LSU和rpb2片段进行了测序和分析,并提供了详细描述、线条图、生态照片及与相似种的区别。拟黄囊丝盖伞以菌盖翘起的鳞片、菌柄纤维状、孢子光滑和厚壁的侧生囊状体为主要识别特征。甘肃丝盖伞具有粗壮的子实体、较大的孢子和厚壁侧生囊状体。基于LSU和rpb2联合数据的分子系统发育分析显示这两个新种隶属于狭义丝盖伞属且分别占据独特的分支。     

The first compression fossils of Spencerites (Scott) emend., and its isospores, from the Bolsovian (Pennsylvanian) of the Kladno-Rakovník and Radnice basins, Czech Republic

Nearly 60 compression fossils of the vegetative stems and fertile zones of Spencerites (Scott) emend. are described from the Bolsovian of the Kladno-Rakovník and Radnice basins in the Czech Republic. Spencerites is re-interpreted as a pseudoherbaceous, repeatedly (minimum three times) dichotomously-branching, lycopsid with fertile apical zones. Vegetative stems are described for the first time. Two new species are proposed: Spencerites havlenae and Spencerites chaloneri. They are generally similar morphologically, and can be distinguished mainly by their isospores. Spencerisporites radiatus Felix and Parks, 1959 emend. isospores were isolated from Spencerites havlenae and Spencerisporites striatus sp. nov. from Spencerites chaloneri. Emendations are proposed for the generic diagnoses of Spencerites and Spencerisporites, and the specific diagnosis of Spencerisporites radiatus.     

来自东亚的黑耳属一新种,亚东黑耳

“亚东黑耳”是西藏近几年备受关注的一种特色野生珍稀食用菌,但对其分类学地位尚无定论。本文基于分子系统学和形态学研究了东亚、欧洲和北美洲与亚东黑耳相近的黑耳属标本,发现碟形黑耳Exidia recisa是个物种复合群,已知包括4个种,欧洲有碟形黑耳和浅波黑耳E. repanda两个种,北美洲有钝齿黑耳E. crenata,东亚的为1新种,本文将其描述为亚东黑耳Exidia yadongensis。这4个种在系统发育关系中相近,形态相似,但亚东黑耳的子实体边缘基本是全缘,担孢子大小为12-16×3-4μm (Q=3.62-3.83),而欧洲的碟形黑耳E. recisa和北美洲的钝齿黑耳E. crenata子实体边缘通常锯齿状,担孢子分别为13-15.5×2.8-3.8μm (Q=4.51)和12-14×3-4μm (Q=4.11),浅波黑耳E. repanda具有垫状至波浪状折叠的子实体,区别于其他3个种的盘状至耳状的子实体,其担孢子为12.7-15.7×2.8-3.7μm (Q=4.33-4.57)。此外,亚东黑耳具有树状分枝和叉形的子实层侧丝,但其他3个种只有树状分枝的子实层侧丝。尽管亚东黑耳广泛分布于东亚地区,但由于亚东黑耳的汉语名称已经在中国普遍使用,所以我们提出了上述拉丁学名。     

Phylogeny,classification, and biogeography of Afrotrichloris,Apochiton, Coelachyrum,Dinebra, Eleusine,Leptochloa, Schoenefeldia,and a new genus,Schoenefeldiella (Poaceae: Chloridoideae: Cynodonteae: Eleusininae)

To investigate the evolutionary relationships among species of Afrotrichloris, Apochiton, Coelachyrum, Dinebra, Eleusine, Leptochloa, and Schoenefeldia of subtribe Eleusininae, a phylogeny based on DNA sequences from nine gene regions (ITS, rps16-trnK, rps3, rps16, rpoC2, rpl32-trnL, ndhF, ndhA, ccsA) is presented. Previous molecular phylogenies indicated that Coelachyrum was polyphyletic and Schoenefeldia was paraphyletic, with Afrotrichloris embedded within it. Apochiton burttii was embedded in the Coelachyrum clade paired with C. longiglume, Coelachyrumpoiflorum was placed outside of Coelachyrum and sister to Eleusine, and Schoenefeldia is paraphyletic, with its two species forming a grade sister to Afrotrichoris. Our molecular phylogeny supports recognition of a new genus, Schoenefeldiella, and a new combination, Schoenfeldiella transiens. In addition, we provide generic emendations for Coelachyrum, which now includes five species including a new combination proposed here, Coelachyrum burttii, and Eleusine, which now includes 11 species.