Search Results: 1 - 10 of 43 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /43
Display every page Item
The New Records of Genera and Species of Xanthophyceae from China

WANG Quan-Xi,LI Hai-Ling,XIE Shu-Lian,

植物科学学报 , 2003,
Abstract: species from Shanxi, Heilongjiang, Shanghai and Zhejiang Provinces belonging to 7 genera of Xanthophyceae were reported as the new records of China. Among them, the 4 genera, Ellipsoidion, Bumilleriopsis, Heterotrichella and Heterothrix are reported for the first time in China.
Susceptibility of Nereocystis luetkeana (Laminariales, Ochrophyta) and Eualaria fistulosa (Laminariales, Ochrophyta) spores to sedimentation  [PDF]
Melissa Deiman*,Katrin Iken,Brenda Konar
Algae , 2012,
Abstract: The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimentation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance in situ. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-forming kelps, Nereocystis luetkeana (K. Mertens) Postels & Ruprecht and Eualaria fistulosa (Postels & Ruprecht) M. J. Wynne, to various types of sediment loading. Spore attachment for both species was significantly and similarly affected by three sediment treatments: suspended particles; settled sediment covering the substratum; and smothering of attached spores by settling sediment. Spore attachment decreased by approximately 90% at 420 mg sediment L-1, the highest sediment load tested here, under all three treatments for both species. These results suggest that increases in sedimentation may constrain the success of the spore stages, but sediment does not seem to be a likely factor explaining species-specific distribution patterns. However, while sedimentation affected spores of both species similarly, timing of spore release in relation to times of maximum sediment load in the water might differ for different species, possibly explaining kelp species distribution patterns.
A Molecular Genetic Timescale for the Diversification of Autotrophic Stramenopiles (Ochrophyta): Substantive Underestimation of Putative Fossil Ages  [PDF]
Joseph W. Brown,Ulf Sorhannus
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0012759
Abstract: Stramenopiles constitute a large and diverse eukaryotic clade that is currently poorly characterized from both phylogenetic and temporal perspectives at deeper taxonomic levels. To better understand this group, and in particular the photosynthetic stramenopiles (Ochrophyta), we analyzed sequence data from 135 taxa representing most major lineages. Our analytical approach utilized several recently developed methods that more realistically model the temporal evolutionary process.
Morphological variability of intertidal Eisenia arborea (Laminariales, Ochrophyta) at Punta Eugenia, Baja California Sur  [PDF]
Gloria M. Parada,Rafael Riosmena-Rodríguez*,Enrique A. Martínez,Gustavo Hernández-Carmona
Algae , 2012,
Abstract: Water motion is one of the main drivers in morphological variability in species within de order Laminariales, and most of our current knowledge is based on subtidal populations. Eisenia arborea is a dominant kelp species in the North Pacific, widely distributed along the Baja California Peninsula from mid intertidal down to subtidal areas. This species presents great variability in the intertidal zone but it has not been yet evaluated such variability according to wave exposure. The present work also identifies the spatial / temporal variation, particularly respect to the presence of stipes without medulla (hollow stipes) a feature common among other brown seaweeds. We evaluated the effects of wave action in morphological variation of intertidal Eisenia arborea (Laminariales, Ochrophyta) at Punta Eugenia. The spatial and temporal variation sampling was surveyed between February, May, July, and August 2004 in the intertidal of Punta Eugenia, Baja California Sur. Our results have shown that exposed sites correlate with increased length and width of stipes as compared to more protected sites. Hollow stipes frequency changed more in association with temporal variation than with spatial heterogeneity suggesting nutrient limitation for thalli development. Our results suggest that Eisenia arborea compensate by morphological modifications the stress of living in the intertidal zone by showing larger stipes. Hollow stipes might be are also a mechanical adaptation to increase survival in high energy environments.
Retroflex?o de bexiga: relato de caso em Blastocerus dichotomus (Cervo-do-Pantanal)
Toniollo, Gilson Hélio;Duarte, José Maurício Barbanti;Delfini, Aline;Monreal, Antonio Carlos Duenhas;
Brazilian Journal of Veterinary Research and Animal Science , 2004, DOI: 10.1590/S1413-95962004000200010
Abstract: a bladder retroflexion was reported in blastocerus dichotomus at the veterinary hospital of fcav jaboticabal-sp. a pregnat female from university breeder showed a retal and bladder prolapse. a cesarean were applied but not sucsseful for both. then, the female was euthanized because the bladder had no conditions to be back again.
Desmídias de ambientes fitotélmicos bromelícolas
Revista Brasileira de Biologia , 1999, DOI: 10.1590/S0034-71081999000100018
Abstract: water is accumulated in phytotelmata (plant pond) of bromeliads and usually favor algal development. twenty-five samples were taken in these environments placed on coastal and mountain regions of rio de janeiro state, brasil. desmids were dominant in nineteen of these samples. ten species, three varieties and one taxonomic form were identified. in addition, representatives of chlorophyceae, cyanophyceae, bacillariophyceae, xanthophyceae and dinophyceae were found.
Invaders in disguise. Conservation risks derived from misidentification of invasive plants
Management of Biological Invasions , 2010,
Abstract: Misidentifications are an important but neglected problem in studies on plant invasions. This review shows how taxonomic education of staff and stakeholders is of great importance for correctly assessing threats provoked by alien plant species in field and literature based studies. Four randomly chosen recent examples (Digitaria violascens, Eleocharis pellucida, Juncus dichotomus and Vicia dalmatica) from Europe demonstrate that, as a result of an initial erroneous identification and/or confusion with similar harmless species, potentially noxious environmental weeds have been able to become fully naturalised. They act as “invaders in disguise” and therefore constitute a real problem for conservation management. Keywords Taxonomy, alien species, Digitaria violascens, Eleocharis pellucida, Juncus dichotomus, Vicia dalmatica Bio-sketch The author has been studying non-native plants (ephemerals as well as invasives) for some 20 years by now. His work chiefly emphasizes on recognition (identification) and taxonomy. F. Verloove has produced lots of publications on naturalized vascular plants in Europe. Since several years, he is working on online "Manual of alien plants of Belgium.
Colectores de algas de México (1787-1954)
Godínez Ortega, José Luis;
Acta botánica mexicana , 2008,
Abstract: biographical as well as bibliographical information is provided about the collectors of algae in mexico during the period 1787-1954. the data were obtained by consulting domestic and foreign herbaria, direct communication with the curators, and revision of relevant literature. information was found concerning 51 collectors, mainly of european and american origin; material collected by them was deposited in 16 herbaria: eight in europe, seven in america and one in australia. the work of collectors gathers information of the phyla: cyanobacteria, rhodophyta, ochrophyta (including phaeophyceae and xanthophyceae), bacillariophyta, chlorophyta and charophyta, the best represented being bacillariophyta and rhodophyta. dates and locations of the regions surveyed in 26 states are included. in the period covered by the study about 477 new species were discovered.
Levantamento populacional do cervo-do-pantanal Blastocerus dichotomus (Mammalia, Cervidae) no Parque Nacional de Ilha Grande e entorno: implica??es para a conserva??o
Tiepolo, Liliani M.;Tomas, Walfrido M.;Lima-Borges, Paulo A.;
Iheringia. Série Zoologia , 2010, DOI: 10.1590/S0073-47212010000200004
Abstract: we conducted an aerial survey of the marsh deer population blastocerus dichotomus (illiger, 1815) in the ilha grande national park and its surroundings, on the border between the states of paraná and mato grosso do sul, brazil, during the dry season. we used the double-counting technique, resulting in a population estimate of 1079 ± 207 marsh deers in a sampled area of 1081 km2, corresponding to an estimated density of 0.998 ± 0.192 ind/km2. the population was mostly concentrated inside the park, but also occupied altered wetlands outside its limits. the results should be used to support population management and conservation measures at the national park and its surroundings, due to the enormous anthropogenic pressure upon the marsh deer population in the region.
Fitoplancton de um reservatório eutrófico (lago Monte Alegre), Ribeir?o Preto, S?o Paulo, Brasil
SILVA, L. H. S.;
Revista Brasileira de Biologia , 1999, DOI: 10.1590/S0034-71081999000200012
Abstract: the study aims at presenting the phytoplankton of a small eutrophic reservoir, located in the southeast of brazil, based in samples fortnightly collected from april of 1988 to march of 1989 from one station located at the centre of the limnetic region. ninety three species were identified, 9 varieties, 5 taxonomic forms, 9 taxa were determined at generic level and 3 were listed in their respective classes, in a total of 119 taxa belonging to 9 taxonomic classes (13 cyanophyceae, 55 chlorophyceae, 15 zygnemaphyceae, 14 euglenophyceae, 5 bacillariophyceae, 3 xanthophyceae, 6 chrysophyceae, 4 cryptophyceae e 4 dinophyceae). it was observed a considerable complexity in the floristic composition in the lake monte alegre, as registered in relation to other tropical lakes and reservoirs, with a bigger dominance of the green algae (59%). the phytoplankton species was used as one of the aspects for the trophic characterization of the environment.
Page 1 /43
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.