883 resultados para PHYLLOGORGIA-DILATATA ESPER
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This study describes the spatio-temporal distribution, population biology, and diet of the puffer fish Lagocephalus laevigatus in Caraguatatuba Bay, south-eastern Brazil. Monthly samples were taken between August 2003 and October 2004 by trawls in two areas, south and north, at depths of 1 to 4 m. The fish were measured and their sex and reproductive stage determined. The abundance of this species was compared between areas and among months, and the items in the diet were identified and quantified. Lagocephalus laevigatus was rare in Caraguatatuba Bay, where only 199 small individuals (4.8 to 15.4 cm) were obtained in the entire study period, suggesting that this species uses the estuary as a nursery. None of the specimens of L. laevigatus captured in Caraguatatuba Bay were sexually mature. Higher densities of L. laevigatus in the bay were recorded in the south area and between October and December 2003, i.e. in the spring, suggesting that spawning may occur from late winter to spring (August through to November). The diet items consumed by L. laevigatus in Caraguatatuba Bay were, as expected from the current literature, crustaceans, mainly amphipods, and fish. However, the most-consumed item was the sea whip Leptogorgia setacea (Cnidaria). This feeding habit may be related to the presence of toxins (tetrodotoxin and saxitoxin) that are frequently found in the skin and viscera of L. laevigatus, which may be sequestered from the sea whip, which possibility still needs to be specifically evaluated.
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Prospectando más de 50 localidades repartidas por todo el Mediterráneo ibérico, hemosencontrado Lithophyllum lichenoides Philippi en las provincias de Gerona, Barcelona y Tarragona. En Alicante, Granada, Cádiz y Baleares hallamos citas bibliográficas, respectivamente, Barceló (1987), Conde & Soto (1985), Seoane (1969) y Ribera (1983). En el resto de lasprovincias del Mediterráneo espaflol no la hemos- encontrado ni fisica ni bibliográficamente. Esprobable que la temperatura del agua y la insolación sean los factores principales que influyenen esta localización (Sanchís, 1986; Zabaleta, 1976). En la zona más septentrional del Meditrráneo ibérico (provincia de Gerona) y en las Islas Baleares, la especie puede verse formando «trottoirs», comisas mediolitorales construidas por confluencia de numerosos talos. En dichas áreas las condiciones de desarrollo son mucho mejores que en las demás zonas observadas por el autor, más meridionales, de la costa mediterránea española. El «trottoir» goza de una gran complejidad estructural, que implica una intensa diversificación de hábitats, aun más acusadapor la variación de condiciones que suponen los cambios estacionales (Sanchís, 1986).
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Mode of access: Internet.
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Coral bleaching (the loss of symbiotic dinoflagellates from reef-building corals) is most frequently caused by high-light and temperature conditions. We exposed the explants of the hermatypic coral Stylophora pistillata to four combinations of light and temperature in late spring and also in late summer. During mid-summer, two NOAA bleaching warnings were issued for Heron Island reef (Southern Great Barrier Reef, Australia) when sea temperature exceeded the NOAA bleaching threshold, and a 'mild' (in terms of the whole coral community) bleaching event occurred, resulting in widespread S. pistillata bleaching and mortality. Symbiotic dinoflagellate biomass decreased by more than half from late spring to late summer (from 2.5x10(6) to 0.8x10(6) dinoflagellates cm(2) coral tissue), and those dinoflagellates that remained after summer became photoinhibited more readily (dark-adapted F (V) : F (M) decreased to (0.3 compared with 0.4 in spring), and died in greater numbers (up to 17% dinoflagellate mortality compared with 5% in the spring) when exposed to artificially elevated light and temperature. Adding exogenous antioxidants (D-mannitol and L-ascorbic acid) to the water surrounding the coral had no clear effect on either photoinhibition or symbiont mortality. These data show that light and temperature stress cause mortality of the dinoflagellate symbionts within the coral, and that susceptibility to light and temperature stress is strongly related to coral condition. Photoinhibitory mechanisms are clearly involved, and will increase through a positive feedback mechanism: symbiont loss promotes further symbiont loss as the light microenvironment becomes progressively harsher.
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丁香属Syringa是木樨科Oleaceae中一个中等大小的属,大多数种类花形美丽,具有很高的园林观赏价值。本文以标本检查为主,结合形态学、孢粉学、细胞学和植物地理学几个方面对丁香属进行了分类研究。 一.形态学:丁香属分类的主要性状为:单叶或复叶、圆锥花序的着生位置、花冠管的长短。这些性状的演化趋势为:单叶--羽状深裂--羽状复叶,圆锥花序由顶芽抽生--圆锥花序由侧芽抽生,长花冠管,雄蕊不伸出花冠管--短花冠管,雄蕊伸出花冠管。 二.孢粉学:本文首次对丁香属的花粉形态作了较为全面而系统的研究。所取材料为各组、系、亚系的代表种。孢粉学的研究表明,本属花粉形态一致。均为近球形,极面观3裂圆形,三(拟)孔沟,沟边缘不加厚,外壁分层明显,外层厚于内层,半覆盖层,粗网状纹饰。扫描电镜观察结果表明,本属花粉的表面纹饰可区分为6种类型:1).网眼小,网脊细、较直而使网眼呈多边形,网脊下小柱不明显,2).网眼稍大,网脊细、直,网脊下小柱不明显,3),网眼较大,网脊细、稍弯曲,网脊下小柱可见,4).网眼大,网脊细而弯曲, 网脊下小明显,5).网眼小,网脊细、弯曲而使网眼呈不规则扁长形,6).网眼较大,网脊粗、直,网脊下小柱不明显。顶生花序系Ser. Villosae (Schneid.) Rehd. 以1型为主,侧生花序系Ser. Syringa从2-4型,羽叶丁香系Ser, Pinnatifolia Rehd,为5型,短花冠管组Sect.Ligustrina Rupr.为6型。其变化规律与形态学上的系统演化关系相—致。 三,细胞学:本文对丁香属部分种进行了染色体数目的观察,初步的结果显示,本属的染色体基数为n=23或24,这两种情况在不同的组、系都存在。本属为异源多倍体起源,由陵花目中染色体基数为n=ll和n=12的祖先类群通过杂交形成,并由于染色体组在减数分裂过程中非整倍性变异,而产生n 2或n=24的变化。 四,分类修订及系统位置和演化趋势: 本文在查看了本所标本馆全部丁香属的标本、考证了约22个种的原始描述以及部分模式标本和模式照片的基础上,对该属分类作下列修订:1.将华丁香Syringa protolaciniata、花叶丁香S.x persica、 裂叶丁香S.x laciniata、阿富汗丁香S.afghanica 四个种从欧丁香亚系中移出,置于羽叶丁香系Ser. Pinnatifolia,2.改欧丁香系Set. Vulgares和巧铃花系Ser. Pubescentes为亚系等级,均置于侧生花序系Ser. Syringa中,3.恢复山丁香Syringa potaninii Schneid.、小叶丁香S.micropylla Diels、关东丁香s.patula (Palibin) Nakai、光萼丁香S.juliana Schneid.、朝鲜丁香S.dilatata Nakai,并作为种的等级,毛萼云南丁香S.yunanensis Franch.f.pubicalyx (Jien ex P.Y. Bai) M.C. Chang仍作变种处理。在此基础上,本文将丁香属分为2组3系2亚系: 组1.长花冠管组Sect.l. Syringa:系1.顶生花序系Ser.1.Villosae(Sch- neid.)Rehd.;系2.侧生花序系Ser.2. Syringa,亚系1.欧丁香亚系Subser.1.Syring,亚系2.巧铃花亚系Pubescentes(Schneid.)Rehd.;系3.羽叶丁香系Ser.3. Pinnatifoliae Rehd. 组2.短花冠管组Sect.2. Ligustrina Rupr. 各分类单元的命名,仍沿用已有的名称。 结合各方面的研究成果,表明丁香属是一个十分自然的类群。在木樨科中,本属与女贞属的关系密切,由女贞属裂果女贞组Sect. Sarcocarpion (Franch.)Mansf.衍生而来。属内演化趋势始为长花冠管组的顶生花序系,而后是侧生花序系、羽叶丁香系,短花冠管组为本属中进化程度较高的类群。 五.植物地理学:丁香属为旧世界温带分布型属,分布区连续。约28种5变种9变型。除2种产于欧洲,1种产于阿富汗、巴基斯坦,1种产于朝鲜,1种产于日本外,其余种类均分布于中国。其中,中国西南地区丁香属的种类、原始类型及其在该地区所占比例均显示是丁香属现代分布中心和起源演化中心,并由此沿三条主线向周围扩散。
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丁香属隶属于木犀科,分布于东南欧和东亚至喜马拉雅地区,我国是丁香属的现代分布中心。《中国植物志》(61卷,1992)记录了我国野生丁香种类16种;《Flora of China》(15卷,1996)记录了中国原产丁香种类16种,并认为全世界大约有20种。丁香属属下分类等级划分分歧较大,很多种的划分也存在争议。花叶丁香、四川丁香等种类是根据栽培植物描述的,没有指定模式标本,给分类处理带来了一定困难。另外,丁香属很多分类群的性状变异非常复杂,仅根据有限的标本很难做出合理的分类处理。本研究通过广泛查阅文献和标本,同时进行野外居群取样和性状观察,对各类群的性状在居群内和居群间的变异进行统计学分析,判断其分类价值,并运用多变量分析的方法,为各类群的合理划分提供依据。结合性状分析和地理分布等证据,做出分类处理。 作者查阅了国内外16个标本馆的近2000份标本,其中模式标本约70份。对我国12个省市的40余个居群进行了取样和观察,采集标本500余份,涉及了《中国植物志》61卷收录的除了藏南丁香以外的所有类群。通过对9个复合体的40余个性状在居群内和居群间的变异进行统计分析,发现叶片类型、叶柄长度、花序着生类型、花冠大小、花丝长度、花药颜色在不同类群间差异明显,可以用作划分种的依据;叶片形状、叶片毛被、花序轴毛被、花冠管形状等性状在有些复合体内的居群间呈现连续的变异,只能用作种下等级(亚种)的划分;叶片大小、花序轴形状、花药着生在花冠的位置、蒴果是否被皮孔等性状在不同复合体的居群间呈现间断或连续的变异,视不同情况可以用作种间或种下等级的划分依据,或作种内变异处理;而叶脉、花色、花萼齿裂、花冠裂片形状等性状在居群间差异不大,不适合用作分类依据。 在性状分析和多变量分析的基础上,本文将丁香属划分为2组2系12种13亚种,其中短花冠管组有1种3亚种;长花冠管组的顶生花序系有5种5亚种,侧生花序系有6种5亚种,并指定了各组和系的模式种;编制了属下各组、系、种和亚种划分的检索表,对12种13亚种进行了形态描述、标本引证,给出了地理分布图和生境,并提出了分类处理依据。文中对巧玲花、皱叶丁香、红丁香和云南丁香等复合体内的一些分类群进行了归并,做出4个新组合:S. pubescens ‘Meyer’、S. villosa subsp. wolfii、S. yunnanensis subsp. sweginzowii和S. yunnanensis subsp. tomentella,处理了11个新异名(S. fauriei H. Lév.、S. julianae C. K. Schneid.、S. meyeri var. spontanea M. C. Chang、S. pinetorum W. W. Sm.、S. wardii W. W. Sm.、S. oblata var. donaldii R. B. Clark et J. L. Fiala、S. afghanica C. K. Schneid.、S. protolaciniata P. S. Green et M. C. Chang、S. tibetica P. Y. Bai、S. reflexa C. K. Schneid. 、S. wilsonii C. K. Schneid.)。作者指定了3种4亚种(S. reticulata subsp. reticulata、 S. reticulata subsp. amurensis、S. pubescens subsp. microphylla、S. oblata subsp. dilatata的后选模式,并对其它10个名称指定了后选模式。文中还提出了分类处理原则,对我国丁 香属的分布及各地方植物志的记载进行了评述,并对丁香属的分布格局提出了作者的看法。 作者还对13个分类群的16号材料进行了染色体观察,发现除了毛丁香有染色体2n=48外,其它均为2n=46,其中朝阳丁香的染色体数目为首次报道。对小叶巧玲花不同异名(包括小叶蓝丁香、小叶巧玲花与小叶蓝丁香的杂交种)的材料进行染色体观察时,发现它们之间差异很小,进一步佐证了作者将其合并的合理性。另外野生的花叶丁香(华丁香)与栽培的花叶丁香在染色体数目上也无差异,支持了作者认为二者为同物异名的观点。
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Twelve commonly occurring coenocytic and siphonaceous species of marine benthic algae, i.e., Bryopsis pennatta Lamouroux, Caulerpa chemnitzia (Esper) Lamouroux, Ca. faridii Nizamuddin, Ca. manorensis Nizamuddin, Ca. racemosa (Forsskal) J. Agardh, Ca. taxifolia. (Vahl) C. Agardh, Chaetomorpha antennina (Bory de Saint-Vincent) Kutzing, Cladophora uncinella Harvey, Codium decorticatum (Woodward) Howe, Co. flabellatum Nizamuddin, Co. iyengarii Borgesen, and Valoniopsis pachynema (Martens) Borgesen, belonging to four different orders of the class Bryopsidophyceae, division Chlorophyta, were collected from the intertidal region of different coastal areas near Karachi (Pakistan) and investigated taxonomically. Codium decorticatum is a new report from this region and Co. decorticatum, Co. flabellatum and Co. iyengarii are described for the first time from the coast of Pakistan.