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Algae
Kinds of Algae Terms modified by Algae Selected AbstractsA TUBULAR MASTIGONEME-RELATED PROTEIN, OCM1, ISOLATED FROM THE FLAGELLUM OF A CHROMOPHYTE ALGA, OCHROMONAS DANICA,JOURNAL OF PHYCOLOGY, Issue 3 2007Takahiro Yamagishi The phylogenetic group stramenopiles refers to the systematic groups that possess tripartite tubular hairs (stramenopiles) on their flagella. There have been a number of studies describing the fine structure of these mastigonemes and a few studies isolating the component proteins; however, these proteins and their gene sequences have not yet been identified. In the present study, we identified a mastigoneme protein (Ocm1) of the chrysophycean alga Ochromonas danica Pringsh. (UTEX LB1298). Its corresponding gene, Ocm1, was identified by using degenerate primers that correspond to the partial amino acid sequences of a protein (85 kDa) obtained from a mastigoneme-rich fraction of isolated flagella. The polypeptide encoded by Ocm1 has four cysteine-rich, epithelial growth factor (EGF),like motifs, potentially involved in protein,protein interactions. It lacks obvious hydrophobic regions characteristic of transmembrane domains, suggesting that this polypeptide is not likely a protein for anchoring the mastigoneme. In addition, a polyclonal antibody against Ocm1 labeled the area where the tubular shafts of the mastigonemes are located, but not the basal portion or the terminal filaments. [source] PHOTOSYNTHETIC UTILIZATION OF INORGANIC CARBON IN THE ECONOMIC BROWN ALGA, HIZIKIA FUSIFORME (SARGASSACEAE) FROM THE SOUTH CHINA SEA,JOURNAL OF PHYCOLOGY, Issue 6 2003Dinghui Zou The mechanism of inorganic carbon (Ci) acquisition by the economic brown macroalga, Hizikia fusiforme (Harv.) Okamura (Sargassaceae), was investigated to characterize its photosynthetic physiology. Both intracellular and extracellular carbonic anhydrase (CA) were detected, with the external CA activity accounting for about 5% of the total. Hizikia fusiforme showed higher rates of photosynthetic oxygen evolution at alkaline pH than those theoretically derived from the rates of uncatalyzed CO2 production from bicarbonate and exhibited a high pH compensation point (pH 9.66). The external CA inhibitor, acetazolamide, significantly depressed the photosynthetic oxygen evolution, whereas the anion-exchanger inhibitor 4,4,-diisothiocyano-stilbene-2,2,-disulfonate had no inhibitory effect on it, implying the alga was capable of using HCO3, as a source of Ci for its photosynthesis via the mediation of the external CA. CO2 concentrations in the culture media affected its photosynthetic properties. A high level of CO2 (10,000 ppmv) resulted in a decrease in the external CA activity; however, a low CO2 level (20 ppmv) led to no changes in the external CA activity but raised the intracellular CA activity. Parallel to the reduction in the external CA activity at the high CO2 was a reduction in the photosynthetic CO2 affinity. Decreased activity of the external CA in the high CO2 grown samples led to reduced sensitiveness of photosynthesis to the addition of acetazolamide at alkaline pH. It was clearly indicated that H. fusiforme, which showed CO2 -limited photosynthesis with the half-saturating concentration of Ci exceeding that of seawater, did not operate active HCO3, uptake but used it via the extracellular CA for its photosynthetic carbon fixation. [source] PYRENOID FORMATION ASSOCIATED WITH THE CELL CYCLE IN THE BROWN ALGA, SCYTOSIPHON LOMENTARIA (SCYTOSIPHONALES, PHAEOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 6 2003Chikako Nagasato Vegetative cells of the brown alga Scytosiphon lomentaria (Lyngbye) Link characteristically have only one chloroplast with a prominent protruding pyrenoid, whereas zygotes have both paternal and maternal chloroplasts. In zygotes, before cell and chloroplast division, each chloroplast has an old and a new pyrenoid. In this study, we raised a polyclonal antibody to RUBISCO and examined the distribution of RUBISCO by immunofluorescence microscopy, focusing on new pyrenoid formation in vegetative cells of gametophytes and zygotes in Scytosiphon. In interphase, only one old pyrenoid was positively indicated by anti-RUBISCO antibody in vegetative cells of gametophytes. From mid-S phase, small fluorescence aggregates reflecting RUBISCO localization started to appear at stroma positions other than adjacent to the old protruding pyrenoid. The fluorescent spots eventually coalesced into a protrusion into the adjacent cytoplasm. We also used inhibitors to clarify the relationship between the cell cycle and new pyrenoid formation, using zygotes after fertilization. When DNA replication was blocked by aphidicolin, new pyrenoid formation was also inhibited. Washing out aphidicolin permitted new pyrenoid formation with the progression of the cell cycle. When mitosis was prolonged by nocodazole, which disrupted the spindle microtubules, the fluorescent masses indicating RUBISCO localization continued to increase when compared with pyrenoid formation in untreated zygotes. During treatment with chloramphenicol, mitosis and cytokinesis were completed. However, there was no occurrence of new RUBISCO localization within the chloroplast stroma beyond the old pyrenoid. From these observations, it seems clear that new pyrenoid formation in the brown alga Scytosiphon depends on the cell cycle. [source] THE , SUBUNITS OF PHYCOERYTHRIN FROM A RED ALGA: POSITION IN PHYCOBILISOMES AND SEQUENCE CHARACTERIZATIONJOURNAL OF PHYCOLOGY, Issue 1 2001Kirk E. Apt Aglaothamnion neglectum Feldman-Mazoyer has two , subunits, ,31 and ,33, that are associated with phycoerythrin in the light-harvesting phycobilisomes. We demonstrate that these subunits are spatially separated within the phycobilisome, with the ,31 subunit present at the distal end of phycobilisome rods and the ,33 subunit present on the proximal end. These subunits are thought to link phycoerythrin hexamers together in the rod substructure, serving a role analogous to that of linker polypeptides of cyanobacteria (although unlike the cyanobacterial linker polypeptides they are chromophorylated). The sequencing of tryptic polypeptides of the , subunits enabled us to prepare oligonucleotides encoding different regions of ,31. These oligonucleotides were used as primers to generate a probe for isolating a ,31 cDNA clone. Characterization of the cDNA clone predicts a polypeptide of 280 amino acids with a 42 amino acid presequence that is characteristic of a transit peptide, the peptide that targets proteins to chloroplasts of vascular plants. The ,31 subunit has 50% similarity to the previously characterized ,33 subunit but has no identifiable similarity to functionally related polypeptides present in cyanobacterial phycobilisomes or to any other polypeptides in the databases. A repeat of 95 amino acids is present in the red algal , subunit sequences, suggesting that these proteins were generated by a gene duplication followed by fusion of the duplicate sequences. [source] Preliminary Submission to the House of Representatives Economic, Finance and Public Administration Committee Inquiry into Cost Shifting by State Governments to Local GovernmentsAUSTRALIAN JOURNAL OF PUBLIC ADMINISTRATION, Issue 4 2002John Pritchard The Australian Local Government Association (ALGA) is the peak body for local authorities across Australia. Representing 698 councils, shires and other local governing bodies, ALGA advocates on behalf of local institutions, the local communities they represent and the process through which they interact. Founded in 1947 by the six states, ALGA now represents all states and territories and is a full member of the Council of Australian Governments (COAG). This article is an edited version of the ALGA's preliminary submission to the House of Representatives Standing Committee inquiry into the Financial Position of, and Cost Shifting onto, Local Government. [source] REDOX PROPERTIES ARE CONSERVED IN RUBISCOS FROM DIATOMS AND GREEN ALGAE THROUGH A DIFFERENT PATTERN OF CYSTEINES,JOURNAL OF PHYCOLOGY, Issue 3 2010Julia Marín-Navarro Eukaryotic RUBISCO appears in two sequence-diverging forms, known as red-like (present in nongreen algae) and green-like (of green algae and higher plants) types. Oxidation of cysteines from green-like RUBISCOs is known to result in conformational changes that inactivate the enzyme and render a relaxed structure more prone to proteolytic attack. These changes may have regulatory value for green algae and higher plants, promoting RUBISCO catabolism under stress conditions. We compare here red-like RUBISCOs from several diatoms with a representative green-like RUBISCO from Chlamydomonas reinhardtii, paying special attention to the cysteine-dependent redox properties. Purified diatom RUBISCO preparations displayed a specific carboxylase activity about one order of magnitude lower than that of the C. reinhardtii P. A. Dang. enzyme. Despite having different patterns of cysteine residues in their primary sequence, the red-like enzymes from diatoms inactivated also through oxidation of cysteine sulfhydryls to disulfides with a transition midpoint identical to that of the green-like forms. Cysteine oxidation resulted also in structural modifications of the diatom RUBISCOs, as recognized by a higher sensitivity of the oxidized enzyme to in vitro proteolysis. The coincident redox properties of red- and green-like RUBISCO types suggest that these changes are part of a physiologically significant regulatory mechanism that has been convergently implemented in both groups with a different set of cysteine residues. [source] UREASE GENE SEQUENCES FROM ALGAE AND HETEROTROPHIC BACTERIA IN AXENIC AND NONAXENIC PHYTOPLANKTON CULTURES,JOURNAL OF PHYCOLOGY, Issue 3 2009Kristopher M. Baker While urea has long been recognized as an important form of nitrogen in planktonic ecosystems, very little is known about how many or which phytoplankton and bacteria can use urea as a nitrogen source. We developed a method, targeting the gene encoding urease, for the direct detection and identification of ureolytic organisms and tested it on seven axenic phytoplankton cultures (three diatoms, two prymnesiophytes, a eustigmatophyte, and a pelagophyte) and on three nonaxenic Aureococcus anophagefferens Hargraves et Sieburth cultures (CCMP1784 and two CCMP1708 cultures from different laboratories). The urease amplicon sequences from axenic phytoplankton cultures were consistent with genomic data in the three species for which both were available. Seven of 12 phytoplankton species have one or more introns in the amplified region of their urease gene(s). The 63 urease amplicons that were cloned and sequenced from nonaxenic A. anophagefferens cultures grouped into 17 distinct sequence types. Eleven types were related to ,-Proteobacteria, including three types likely belonging to the genus Roseovarius. Four types were related to ,-Proteobacteria, including two likely belonging to the genus Marinobacter, and two types were related to ,-Proteobacteria. Terminal restriction fragment length polymorphism (TRFLP) analyses suggested that the sequenced amplicons represented approximately half of the diversity of bacterial urease genes present in the nonaxenic cultures. While many of the bacterial urease sequence types were apparently lab- or culture-specific, others were found in all three nonaxenic cultures, suggesting the possibility of specific relationships between these bacteria and A. anophagefferens. [source] PHYLOGENETIC ANALYSIS OF PSEUDOCHLORODESMIS STRAINS REVEALS CRYPTIC DIVERSITY ABOVE THE FAMILY LEVEL IN THE SIPHONOUS GREEN ALGAE (BRYOPSIDALES, CHLOROPHYTA),JOURNAL OF PHYCOLOGY, Issue 3 2009Heroen Verbruggen The genus Pseudochlorodesmis (Bryopsidales) is composed of diminutive siphons of extreme morphological simplicity. The discovery of Pseudochlorodesmis -like juveniles in more complex Bryopsidales (e.g., the Halimeda microthallus stage) jeopardized the recognition of this genus. Confronted with this uncertainty, taxonomists transferred many simple siphons into a new genus, Siphonogramen. In this study, we used a multimarker approach to clarify the phylogenetic and taxonomic affinities of the Pseudochlorodesmis-Siphonogramen (PS) complex within the more morphologically complex bryopsidalean taxa. Our analyses reveal a new layer of diversity largely distinct from the lineages containing the structurally complex genera. The PS complex shows profound cryptic diversity exceeding the family level. We discuss a potential link between thallus complexity and the prevalence and profundity of cryptic diversity. For taxonomic simplicity and as a first step toward clarifying the taxonomy of these simple siphons, we propose to maintain Pseudochlorodesmis as a form genus and subsume Siphonogramen and Botryodesmis therein. [source] BIODIVERSITY OF CORALLINE ALGAE IN THE NORTHEASTERN ATLANTIC INCLUDING CORALLINA CAESPITOSA SP.JOURNAL OF PHYCOLOGY, Issue 1 2009NOV. (CORALLINOIDEAE, RHODOPHYTA) The Corallinoideae (Corallinaceae) is represented in the northeastern Atlantic by Corallina officinalis L.; Corallina elongata J. Ellis et Sol.; Haliptilon squamatum (L.) H. W. Johans., L. M. Irvine et A. M. Webster; and Jania rubens (L.) J. V. Lamour. The delimitation of these geniculate coralline red algae is based primarily on morphological characters. Molecular analysis based on cox1 and 18S rRNA gene phylogenies supported the division of the Corallinoideae into the tribes Janieae and Corallineae. Within the Janieae, a sequence difference of 46,48 bp (8.6%,8.9%) between specimens of H. squamatum and J. rubens in the cox1 phylogeny leads us to conclude that they are congeneric. J. rubens var. rubens and J. rubens var. corniculata (L.) Yendo clustered together in both phylogenies, suggesting that for those genes, there was no genetic basis for the morphological variation. Within the Corallineae, it appears that in some regions, the name C. elongata has been misapplied. C. officinalis samples formed two clusters that differed by 45,54 bp (8.4%,10.0%), indicating species-level divergence, and morphological differences were sufficient to define two species. One of these clusters was consistent with the morphology of the type specimen of C. officinalis (LINN 1293.9). The other species cluster is therefore described here as Corallina caespitosa sp. nov. This study has demonstrated that there is a clear need for a revision of the genus Corallina to determine the extent of "pseudocryptic" diversity in this group of red algae. [source] AIRBORNE ALGAE: THEIR PRESENT STATUS AND RELEVANCE,JOURNAL OF PHYCOLOGY, Issue 4 2007Naveen Kumar Sharma Ongoing climatic changes coupled with various natural processes and the outcomes of human activities are not only loading the atmosphere with diverse kinds of biological particles but also changing their prevalence and spatial distribution. Despite having considerable ecological and economic significance, including their possible impact on human health, airborne algae are the least-studied organisms in both aerobiological and phycological studies. The present review has been written to bring together all available information, including a brief survey of the literature, the ecology of airborne algae, mechanisms involved in their aerosolization, the role of environmental factors in shaping the structure and composition of aero-algal flora, and other significant information associated with airborne algae. This review provides information on methodological approaches and related problems, along with suggestions for areas of future research on airborne algae. [source] DEFINING THE MAJOR LINEAGES OF RED ALGAE (RHODOPHYTA),JOURNAL OF PHYCOLOGY, Issue 2 2006Hwan Su Yoon Previous phylogenetic studies of the Rhodophyta have provided a framework for understanding red algal phylogeny, but there still exists the need for a comprehensive analysis using a broad sampling of taxa and sufficient phylogenetic information to clearly define the major lineages. In this study, we determined 48 sequences of the PSI P700 chl a apoprotein A1 (psaA) and rbcL coding regions and established a robust red algal phylogeny to identify the major clades. The tree included most of the lineages of the Bangiophyceae (25 genera, 48 taxa). Seven well-supported lineages were identified with this analysis with the Cyanidiales having the earliest divergence and being distinct from the remaining taxa; i.e. the Porphyridiales 1,3, Bangiales, Florideophyceae, and Compsopogonales. We also analyzed data sets with fewer taxa but using seven proteins or the DNA sequence from nine genes to resolve inter-clade relationships. Based on all of these analyses, we propose that the Rhodophyta contains two new subphyla, the Cyanidiophytina with a single class, the Cyanidiophyceae, and the Rhodophytina with six classes, the Bangiophyceae, Compsopogonophyceae, Florideophyceae, Porphyridiophyceae classis nov. (which contains Porphyridium, Flintiella, and Erythrolobus), Rhodellophyceae, and Stylonematophyceae classis nov. (which contains Stylonema, Bangiopsis, Chroodactylon, Chroothece, Purpureofilum, Rhodosorus, Rhodospora, and Rufusia). We also describe a new order, Rhodellales, and a new family, Rhodellaceae (with Rhodella, Dixoniella, and Glaucosphaera). [source] COMMON EVOLUTIONARY ORIGIN OF STARCH BIOSYNTHETIC ENZYMES IN GREEN AND RED ALGAE,JOURNAL OF PHYCOLOGY, Issue 6 2005Nicola J. Patron Plastidic starch synthesis in green algae and plants occurs via ADP-glucose in likeness to prokaryotes from which plastids have evolved. In contrast, floridean starch synthesis in red algae proceeds via uridine diphosphate-glucose in semblance to eukaryotic glycogen synthesis and occurs in the cytosol rather than the plastid. Given the monophyletic origin of all plastids, we investigated the origin of the enzymes of the plastid and cytosolic starch synthetic pathways to determine whether their location reflects their origin,either from the cyanobacterial endosymbiont or from the eukaryotic host. We report that, despite the compartmentalization of starch synthesis differing in green and red lineages, all but one of the enzymes of the synthetic pathways shares a common origin. Overall, the pathway of starch synthesis in both lineages represents a chimera of the host and endosymbiont glycogen synthesis pathways. Moreover, host-derived proteins function in the plastid in green algae, whereas endosymbiont-derived proteins function in the cytosol in red algae. This complexity demonstrates the impacts of integrating pathways of host with those of both primary and secondary endosymbionts during plastid evolution. [source] GENE SEQUENCE DIVERSITY AND THE PHYLOGENETIC POSITION OF ALGAE ASSIGNED TO THE GENERA PHAEOPHILA AND OCHLOCHAETE (ULVOPHYCEAE, CHLOROPHYTA),JOURNAL OF PHYCOLOGY, Issue 4 2004Charles J. O'Kelly The phylogenetic position of microfilamentous marine green algae assigned to the species Phaeophila dendroides, Entocladia tenuis (Phaeophila tenuis, and Ochlochaete hystrix was examined through phylogenetic analyses of nuclear-encoded small subunit rDNA and chloroplast-encoded tufA gene sequences. These analyses placed the P. dendroides strains within the Ulvophyceae, at the base of a clade that contains representatives of the families Ulvaceae, Ulvellaceae, and the species Bolbocoleon piliferum, supporting an earlier hypothesis that P. dendroides constitutes a distinct lineage. Substantial divergence in both nuclear and plastid DNA sequences exists among strains of P. dendroides from different geographic localities, but these isolated strains are morphologically indistinguishable. The lineage may have an accelerated rate of gene sequence evolution relative to other microfilamentous marine green algae. Entocladia tenuis and O. hystrix are placed neither in the P. dendroides clade nor in the Ulvellaceae as previous taxonomic schemes predicted but instead form a new clade or clades at the base of the Ulvaceae. Ruthnielsenia gen. nov. is proposed to accommodate Kylin's species, which cannot be placed in Entocladia (=Acrochaete), Phaeophila, or Ochlochaete. Ruthnielsenia tenuis (Kylin) comb. nov., previously known only from Atlantic coasts, is reported for the first time from the Pacific coast of North America (San Juan Island, WA, USA). Isolates of R. tenuis from the Atlantic and Pacific coasts of North America have identical small subunit rDNA and tufA gene sequences. [source] THE MESOZOIC RADIATION OF EUKARYOTIC ALGAE: THE PORTABLE PLASTID HYPOTHESIS,JOURNAL OF PHYCOLOGY, Issue 2 2003Daniel Grzebyk Although all chloroplasts appear to have been derived from a common ancestor, a major schism occurred early in the evolution of eukaryotic algae that gave rise to red and green photoautotrophic lineages. In Paleozoic and earlier times, the fossil record suggests that oceanic eukaryotic phytoplankton were dominated by the green (chl b -containing) algal line. However, following the end-Permian extinction, a diverse group of eukaryotic phytoplankton evolved from secondary symbiotic associations in the red (chl c -containing) line and subsequently rose to ecological prominence. In the contemporary oceans, red eukaryotic phytoplankton taxa continue to dominate marine pelagic food webs, whereas the green line is relegated to comparatively minor ecological and biogeochemical roles. To help elucidate why the oceans are not dominated by green taxa, we analyzed and compared whole plastid genomes in both the red and green lineages. Our results suggest that whereas all algal plastids retain a core set of genes, red plastids retain a complementary set of genes that potentially confer more capacity to autonomously express proteins regulating oxygenic photosynthetic and energy transduction pathways. We hypothesize that specific gene losses in the primary endosymbiotic green plastid reduced its portability for subsequent symbiotic associations. This corollary of the plastid "enslavement" hypothesis may have limited subsequent evolutionary advances in the green lineage while simultaneously providing a competitive advantage to the red lineage. [source] EFFECT OF TAXON SAMPLING, CHARACTER WEIGHTING, AND COMBINED DATA ON THE INTERPRETATION OF RELATIONSHIPS AMONG THE HETEROKONT ALGAE,JOURNAL OF PHYCOLOGY, Issue 2 2003Leslie R. Goertzen Nuclear ribosomal small subunit and chloroplast rbcL sequence data for heterokont algae and potential outgroup taxa were analyzed separately and together using maximum parsimony. A series of taxon sampling and character weighting experiments was performed. Traditional classes (e.g. diatoms, Phaeophyceae, etc.) were monophyletic in most analyses of either data set and in analyses of combined data. Relationships among classes and of heterokont algae to outgroup taxa were sensitive to taxon sampling. Bootstrap (BS) values were not always predictive of stability of nodes in taxon sampling experiments or between analyses of different data sets. Reweighting sites by the rescaled consistency index artificially inflates BS values in the analysis of rbcL data. Inclusion of the third codon position from rbcL enhanced signal despite the superficial appearance of mutational saturation. Incongruence between data sets was largely due to placement of a few problematic taxa, and so data were combined. BS values for the combined analysis were much higher than for analyses of each data set alone, although combining data did not improve support for heterokont monophyly. [source] FERRIC CHELATE REDUCTASE ACTIVITY AS AFFECTED BY THE IRON-LIMITED GROWTH RATE IN FOUR SPECIES OF UNICELLULAR GREEN ALGAE (CHLOROPHYTA)1JOURNAL OF PHYCOLOGY, Issue 3 2002Harold G. Weger Four species of green algae (Chlorella kessleri Fott et Nováková, Chlorococcum macrostigmatum Starr, Haematococcus lacustris[Girod-Chantrans] Rostaf., Stichococcus bacillaris Näg.) were grown in iron-limited chemostats and under phosphate limitation and iron (nutrient) sufficiency. For all four species, steady-state culture density declined with decreasing degree of iron limitation (increasing iron-limited growth rate), whereas chl per cell or biovolume increased. Plasma membrane ferric chelate reductase activity was enhanced by iron limitation in all species and suppressed by phosphate limitation and iron sufficiency. These results confirm previous work that C. kessleri uses a reductive mechanism of iron acquisition and also suggest that the other three species use the same mechanism. Although imposition of iron limitation led to enhanced activities of ferric chelate reductase in all species, the relationship between ferric chelate reductase activity and degree of iron limitation varied. Ferric chelate reductase activity in C. macrostigmatum and S. bacillaris was an inverse function of the degree of iron limitation, with the most rapidly growing iron-limited cells exhibiting the highest ferric chelate reductase activity. In contrast, ferric chelate reductase activity was only weakly affected by the degree of iron limitation in C. kessleri and H. lacustris. Calculation of ferric reductase activity per unit chl allowed a clear differentiation between iron-limited and iron-sufficient cells. The possible extension of the ferric chelate reductase assay to investigate the absence or presence of iron limitation in natural waters may be feasible, but it is unlikely that the assay could be used to estimate the degree of iron limitation. [source] GREEN ALGAE AND LAND PLANTS,AN ANSWER AT LAST?JOURNAL OF PHYCOLOGY, Issue 2 2002Russell L. Chapman First page of article [source] MARINE ALGAE ASSOCIATED WITH CARIBBEAN ROCKY SHORES, QUINTANA ROO, MEXICOJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Albert, E. M. & Lehman, R. L. Center for Coastal Studies, Texas A&M University-Corpus Christi, Corpus Christi, TX 78412 USA Rocky shores located on the east coast of the Yucatan Peninsula are typically high-energy habitats associated with fringing or barrier reef systems. They are phytokarstic (iron-shore) consisting of fossiliferous limestone that is composed of stony coral skeletons. This study compares the macroalgae from three rocky shores located on the east coast of the Yucatan Peninsula, Quintana Roo, Mexico. Fifteen 0.25m2 quadrates were randomly placed in the intertidal and subtidal zones and evaluated for dominant algal cover. In addition, fifteen 0.25 m2 quadrates of standing stock material was randomly collected and used to characterize algal composition, species richness, abundance, and biomass. A voucher collection including herbarium mounts and preserved specimens were prepared for all species encountered. Thirty-five species were identified representing three divisions: Rhodophyta, Chlorophyta, and Phaeophyta. Rhodophyta had the highest species richness with a total of fifteen taxa identified. Phaeophyta had the lowest species richness with seven taxa but dominated algal coverage at two of the three sites. Chlorophyta was represented by thirteen species. Species common to all points were represented by Digenia simplex, Laurencia poiteaui, Laurencia sp., Polysiphonia sp., Microdictyon marinum, Halimeda opuntia, Dictyosphaeria cavernosa, Padina sanctae-crucis, and Turbinaria tricostata. [source] EFFECTS OF BARLEY STRAW EXTRACT ON GROWTH OF FIVE SPECIES OF PLANKTONIC ALGAEJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Holz, J. C.1, Fessler, C. J.2, Severn, A. A.1 & Hoagland, K. D.1 1School of Natural Resource Sciences, University of Nebraska, 103 Plant Industry Bldg., Lincoln, NE, 68583-0814; 2Biology Department, Nebraska Wesleyan University, 5000 St. Paul Ave., Lincoln, NE, 68504; Phone: 402-472-6648; Fax: 402-472-2964 The effects of exposure to barley straw extract and the timing of exposure on the growth of four common cyanophyte species and one species of green algae were investigated in two laboratory experiments. Clonal cultures of Anabaena cylindrica, Cylindrospermum sp., Gloeocapsa sp., Eucapsis sp., and Chlorella vulgaris were obtained from culture collections. In both experiments, the algae were cultured in Guillard's WC medium at 20 °C on a 12:12 L/D photoperiod. In the first experiment, the algae were dosed with four concentrations of barley straw extract at the beginning of the experiment (day 0) and growth was monitored every second day using fluorometric detection of chlorophyll a for 14 d. In the second experiment, the algae were dosed with the same extract concentrations, but the extract was not added until the algae were in exponential growth phase (day 6). Both experiments also had control treatments (i.e. no extract) and each extract and control treatment was replicated five times. Growth of C. vulgaris was inhibited by all doses in both experiments, but inhibition was 22% greater when the extract was added on day 0. Growth Gleocapsa sp. was slightly inhibited by all doses when the extract was added on day 0, but not when it was added on day 6. No other species were inhibited, regardless of dose or timing of dose. The results of this study and other bioassay studies suggest that differential susceptibility to barley straw among algae is common and may reduce the effectiveness of barley straw as an algal control technique. [source] BIOGEOGRAPHY OF MARINE RED ALGAE: MYTHS AND REALITIESJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Hommersand, M. H. Department of Biology, Coker Hall, University of North Carolina, Chapel Hill, NC 27599-3280 USA Theories about the geographical distribution of marine algae fall roughly into two categories: (1) a concept of biogeographical regions in which algal distribution is determined primarily by growth, reproductive and lethal temperature boundaries (Setchell, van den Hoek, Breeman, Lüning) and (2) an historical perspective in which distribution is determined primarily by patterns of dispersal and the establishment of barriers to dispersal (vicariance biogeography) (Svedelius, Garbary, Lindstrom, Hommersand). Setchell proposed the 5° isotherm rule in 1920, and in 1924 Svedelius advocated a worldwide distribution for tropical and subtropical groups followed by discontinuous distribution upon closure of the connection between the Indian Ocean and Mediterranean Sea and, later, between North and South America (Wegener's theory). Transarctic dispersal routes have received special attention in recent years (Lindstrom, Lüning, van Oppen, Olsen, Stam), as have special relationships between Australasia, South Africa and South America (Hommersand). Less well understood are the climatic changes that have taken place in the Cenozoic which are strategic to an understanding vicariant biogeography. The advent of molecular methods combined with the tools of phylogenetic systematics now make it possible to identify ancestral taxa, test the consistency of tree topologies, and calculate mean branch lengths between sister lineages diverging from an interior node of a tree. With such methods it may be possible to infer ancestral areas, identify dispersal pathways, determine the chronology of isolating events, assess the impact of multiple invasions, and generally relate dispersal and vicariance models to phylogenetic hypotheses for red, brown and green algal taxa. [source] THE END-PERMIAN MASS EXTINCTION WAS SYNCHRONOUS COINCIDED WITH THE EVOLUTION OF TOXIC ALGAEJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Lee, R. E.1 & Kugrens, P.2 1Department of Biomedical Sciences, College of Veterinary Medicine, Colorado State University, Fort Collins, CO 80523; 2Department of Biology, Colorado State University, Fort Collins, Co 80523 USA The cause of the end-Permian mass extinction, the greatest of all mass extinctions, is one of the most intriguing mysteries in the history of life. The end-Permian mass extinction was primarily a marine event, resulting principally in the elimination of sessile filter-feeding organisms. Based on two methods, molecular clocks and correlation with ancient atmospheric CO2, the algae derived from secondary endosymbioses are believed to have originated in the middle to late Permian. All of the toxic marine algae in today's oceans are derived from secondary endosymbioses. Therefore it appears likely that the end-Permian extinction was due to the evolution of toxic algae in the phytoplankton of late-Permian seas. Sieving of the toxic algae in the phytoplankton likely resulted in the decline and eventual elimination of a large portion of the Paleozoic fauna during the end-Permian mass extinction. [source] POPULATION DYNAMICS AND THE TOXICITY OF BLUE-GREEN ALGAE IN THE NAKTONG RIVER, KOREAJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Lee, J. A.1, Choi, A. R.1, Park, J. H.1 & Chung, I. K2 1Department of Environmental Science, Inje University, Kimhae 621-749, Korea; 2Departement of Marine Science, Pusan National University, Pusan 609-735, Korea Seasonal and spatial variations of phytoplankton community were monitored at 16 sites along the Naktong River. Blue-green algae appeared from May through November with dominant genera of Microcystis, Anabaena, Oscillatoria and Gomphosphaeria. Frequency and biomass of the genera became greater at lower reaches. The Microcystis were observed from May to October up to 85,750cells/ml. Six species of Microcystis were identified with morphological characteristics and M. aeruginosa was most dominant. There were significant relationships between biomass of Microcystis and NO -3, TP and pH in water column. However, NH4+, PO4 -3 and N/P were not critical in successions to the Microcystis dominated community. Microcystis blooms were notable at water temperature higher than 25°C. Microcystis density in sediment was 3 orders of magnitude higher than water column. Anabaena density ranged up to 11,220cells/ml. Four species of Anabaena were identified and A. flos-aquae was most dominant. Anabaena biomass was not related to temperature, NO3 - , TN, PO4 -3, TP and N/P of water column and the frequency of trichome with akinete and/or heterocyte were not related to these parameters. Microcystins were detected from May to November with yearly fluctuations. Microcystin-RR was most dominant. Total 84.2% of algal materials with Microcystis exhibited toxicity of microcystin with maximum of 3,292,g/g dry wt. Total 12.5% of water column with Microcystis exhibited dissolved microcystin up to 3.3,g/l. Microcystin concentrations were positively related to Microcystis biomass and pH of water column. Anatoxin-a was determined by FD-HPLC analysis with NBD-F and all concentrations were below the detection limit of 0.1,g/l. [source] SNOW ALGAE OF THE WINDMILL ISLANDS, CONTINENTAL ANTARCTICA: DESMOTETRA AUREOSPORA, SP.JOURNAL OF PHYCOLOGY, Issue 1 2001Two cryophilic Desmotetra species, D. aureospora, sp. nov., and D. antarctica (Fritsch) Ling appear to be unique to the southern hemisphere snow ecosystem, or at least to the Windmill Island region, Antarctica. They have not been encountered in previous extensive studies of the Arctic and northern alpine regions. Also unusual are the higher pH (6.8 and 7.8) and conductivities of 279 ,S·cm,1 and 426 ,S·cm,1 for habitat conditions of D. antarctica that can be attributed to the influence of penguin guano. Both species are characterized by cells enveloped in individual mucilage layers, 1,3 contractile vacuoles, and a cup-shaped chloroplast containing a diffuse pyrenoid. The cells divided in three planes to form cubical loosely aggregated green cell packages embedded in mucilage. Vegetative cells of the two species cannot be distinguished with certainty; however, their zygospores are very different. Desmotetra aureospora has spherical, smooth-walled, golden zygospores, whereas D. antarctica has pale, yellow green, aereolate zygospores. Mucilage stalk morphology of cells in stationary-phase cultures can also be used to separate the two species. Zygospores of D. antarctica have previously been identified as the snow alga Trochiscia antarctica Fritsch. Both species are currently maintained in culture at the Australian Antarctic Division. The cultures did not grow at temperatures above 15° C. The two species are compared with the soil alga D. stigmatica (Deason) Deason et Floyd, the only other species in the genus, and also with Chlorosarcina stigmatica Deason strain T105. Results show that the three Desmotetra species form a natural group and that the absence or presence of a wall on the zoospore is of dubious value in classifications of green algal taxa above the species level. [source] POTENTIAL TOOLS FOR TRACKING OCEAN CLIMATE: VARIABILITY IN STABLE ISOTOPES IN LIVING CORALLINE ALGAEJOURNAL OF PHYCOLOGY, Issue 2000R.A. Dunn Our ability to track long term climate change in coastal regions is limited in temperate and polar regions. Physical oceanographic dynamics in temperature and upwelling events can be recorded as carbon and oxygen stable isotope signals in carbonate producing organisms. Because coralline algae photosynthesize, produce calcium carbonate and are widely distributed, they may provide a new tool for detecting short-term change. However, little is known about how coralline algae incorporate stable isotopes into their calcite thallus structure. The objectives of this study were to determine if growth and isotopic signature differ in articulated coralline algae grown in different oceanographic regimes in Monterey Bay. The articulated alga Calliarthron cheiliospororioides was outplanted at three locations varying in seawater temperature and upwelling strength. New algal growth was measured by staining the algae with Alizarin Red and enumerating the amount of accumulated material at the branch tips. Growth rates varied seasonally and spatially. Low-upwelling daily growth rates averaged 0.044,0.056 mm day,1, while high-upwelling growth rates were 0.083 mm day,1. Isotope ratios were obtained by analyzing microsampled portions of the alga in a mass spectrometer. Changes in the 18O/16O and 13C/12C ratios appear to reflect change in seawater temperature and upwelling strength, respectively. [source] CELL WALL BIOLOGY IN RED ALGAE: DIVIDE AND CONQUERJOURNAL OF PHYCOLOGY, Issue 5 2000Valerie Vreeland First page of article [source] FRESHWATER ALGAE FROM THE UPPER TRIASSIC CUYANA BASIN OF ARGENTINA: PALAEOENVIRONMENTAL IMPLICATIONSPALAEONTOLOGY, Issue 6 2006ANA M. ZAVATTIERI Abstract:, Diverse freshwater aquatic palynomorphs are present among rich terrestrial palynofloras from the upper part of the Potrerillos and Cacheuta formations outcropping in the Cuyana Basin at the southern extremity of the Precordillera of Argentina. The Potrerillos/Cacheuta sequence includes fluvial, deltaic and lacustrine facies deposited in the early Late Triassic fault-bounded syn-rift Cacheuta hemigraben. The phytoplankton described and illustrated consist of representatives of colonial chlorococcalean algae belonging to the Hydrodictyaceae (Plaesiodictyon) and Botryococcaceae (Botryococcus), a diverse group of Zygnemataceae zygospores, a freshwater dinoflagellate cyst (Bosedinia) and acritarchs (sphaeromorphs). Zygnematacean zygospores are represented by species of Gelasinicysta?, Lecaniella, Mougeotia, Ovoidites, Peltacystia and Schizocystia. Of these, Gelasinicysta? cuyanensis sp. nov. is newly described. Quantitative analysis of the palynofloras permits interpretation of changes in the local vegetation and phytoplankton communities controlled by changes in environmental setting. Two algal associations are recognized as belonging to different stages in the evolution of the basin. Diverse zygnematacean assemblages along with hydrodictyacean, botryococcacean and leiosphere/sphaeromorph algae are common in fluvial,deltaic environments of the upper part of the Potrerillos Formation and the lowermost part of the Cacheuta Formation. Higher in the sections (in the Cacheuta Formation) Botryococcus dominates, in association with amorphous kerogen, representing deposition in a relatively deep, quiet-water, lacustrine environment where anoxic conditions prevailed. In the Cacheuta hemigraben the lacustrine shales have average TOC values of 4 per cent (locally reaching 20 per cent), with some terrigenous components (Type II/III kerogen), but dominant amorphous, algal-like, organic matter (Type I/II kerogen). Oils derived from these source rocks are predominantly waxy. [source] Equal Sex Ratios of a Marine Green Alga, Bryopsis plumosaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2008Tatsuya Togashi Abstract By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa (Hudson) C. Agardh. In this study, we focused on the primary and secondary sex ratios (i.e. at inception and maturity) using these culture techniques. Gametogenesis was induced by culturing haploid gametophytes with Provasoli's enriched seawater (PES) medium under a 14:10 h light : dark cycle at 14 °C. Formed zygotes grew into diploid sporophytes, which were cultured for 3 months with PES medium under a 14:10 h light : nbsp;dark cycle at 18 °C. Then they were transferred into Schreiber medium and cultured under a 10:14 h light : dark cycle at 22 °C. Within 1 week, zoosporogenesis was observed. Zoospores were released within a couple of days. Each zoospore soon germinated and grew into a unisexual gametophyte. The primary sex ratio was examined in gametophytes that originated from a single sporophyte. The secondary sex ratio was studied in the field. Both were estimated as 1:1. Synchronized meiotic cell divisions might occur during zoosporogenesis dividing each sex-determining factor evenly among zoospores. Given the equal sex ratio at maturity, there seems to be no environmental factor that differentially affects the survival of male or female gametophytes in nature. [source] Reestablishment of the Southern California Rocky Intertidal Brown Alga, Silvetia compressa: An Experimental Investigation of Techniques and Abiotic and Biotic Factors That Affect Restoration SuccessRESTORATION ECOLOGY, Issue 2010Stephen G. Whitaker Previous research has indicated that many rocky intertidal macrophyte communities in southern California, and other locations around the world, have shifted from larger, highly productive, fleshy seaweeds toward a smaller, less productive, disturbance-tolerant flora. In widespread decline are ecologically important, canopy-forming, brown seaweeds, such as the southern California rockweed species Silvetia compressa. Restoration efforts are common for depleted biogenic species in other habitats, but restoration within rocky intertidal zones, particularly on wave-exposed coasts, has been largely unexplored. In two phases, we attempted to restore Silvetia populations on a southern California shore by transplanting live plants and experimentally investigating factors that affect their survival. In Phase I, we implemented a three-way factorial design where juvenile Silvetia thalli were transplanted at four sites with a combination of simulated canopy and herbivore exclusion treatments. Transplant survival was low, although enhanced by the presence of a canopy; site and herbivore presence did not affect survival. In Phase II, we used a two-way factorial design, transplanting two size classes of rockweeds (juveniles and reproductive adults) on horizontal and partially shaded, north-facing vertical surfaces at a target location where this rockweed has been missing since at least the 1970s. Transplant survival was moderate but lower than natural survival rates. Larger thalli exhibited significantly higher survival rates than smaller thalli in both the transplanted and naturally occurring populations, particularly on vertical surfaces. Higher mortality on horizontal surfaces may have been due to differences in desiccation stress and human trampling. Transplanting reproductive adults resulted in the subsequent recruitment of new individuals. [source] Photosynthetic Eukaryotes of Freshwater Wetland Biofilms: Adaptations and Structural Characteristics of the Extracellular Matrix in the Green Alga, Cosmarium reniforme (Zygnematophyceae, Streptophyta)THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2009DAVID S. DOMOZYCH ABSTRACT. Cosmarium reniforme (Zygnematophyceae, Streptophyta) is a green alga that is commonly found in biofilms of wetlands of the Adirondack region, NY (USA). Two distinctive characteristics that are critical to this alga's survival in a benthic biofilm are its elaborate cell morphology and extracellular matrix (ECM). In this study, ultrastructural, immunocytochemical, and experimental methodologies were employed in order to elucidate the cellular characteristics that are critical for survival in a biofilm. The ECM consists of a thick, outwardly lobed cell wall (CW), which contains a patterned network of structurally complex pores. Each pore consists of a narrow channel, terminating internally at a bulb that invaginates localized regions of the plasma membrane. The outer region of the pore contains arabinogalactan protein-like and extensin epitopes that are likely involved in adhesion mechanisms of the cell. External to the CW is the extracellular polymeric substance that is employed in ensheathment of the cell to the substrate and in gliding motility. The architectural design/biochemical make-up of the CW and a secretory system that encompasses the coordinated activities of the endomembrane and cytomotile/cytoskeletal systems provide the organism with effective mechanisms to support life within the biofilm complex. [source] Conservation of the Biodiversity of Brazil's Inland WatersCONSERVATION BIOLOGY, Issue 3 2005ANGELO A. AGOSTINHO Threatened freshwater species include 44 species of invertebrates (mostly Porifera) and 134 fishes (mostly Cyprinodontiformes, Rivulidae), primarily distributed in south and southeastern Brazil. Reasons for the declines in biodiversity in Brazilian inland waters include pollution and eutrophication, siltation, impoundments and flood control, fisheries, and species introductions. These problems are more conspicuous in the more-developed regions. The majority of protected areas in Brazil have been created for terrestrial fauna and flora, but they also protect significant water bodies and wetlands. As a result, although very poorly documented, these areas are of great importance for aquatic species. A major and pressing challenge is the assessment of the freshwater biodiversity in protected areas and surveys to better understand the diversity and geography of freshwater species in Brazil. The concept of umbrella species (e.g., certain migratory fishes) would be beneficial for the protection of aquatic biodiversity and habitats. The conservation and improved management of river corridors and associated floodplains and the maintenance of their hydrological integrity is fundamental to preserving Brazil's freshwater biodiversity and the health of its aquatic resources. Resumen:,En términos de biodiversidad, las aguas interiores de Brasil son de enorme importancia global para Algae (25% de las especies del mundo), Porifera (Demospongiae, 33%), Rotifera (25%), Cladocera (Branchiopoda, 20%) y peces (21%). Las especies dulceacuícolas amenazadas incluyen a 44 especies de invertebrados (la mayoría Porifera) y 134 de peces (en su mayor parte Cyprinodontiformes, Rivulidae), distribuidos principalmente en el sur y sureste de Brasil. Las razones de la declinación en la biodiversidad de aguas interiores de Brasil incluyen contaminación y eutrofización, sedimentación, represas y control de inundaciones, pesquerías e introducción de especies. Estos problemas son más conspicuos en las regiones más desarrolladas. La mayoría de las áreas protegidas en Brasil han sido creadas para fauna y flora terrestres, pero también protegen a considerable número de cuerpos de agua y humedales y, aunque muy deficientemente documentado, como tales son de gran importancia para las especies acuáticas. La evaluación de la biodiversidad dulceacuícola en áreas protegidas y muestreos para un mejor entendimiento de la diversidad y geografía de especies dulceacuícolas de Brasil son un reto mayor y apremiante. El concepto de especies sombrilla (e.g., ciertos peces migratorios) sería benéfico para la protección de biodiversidad y hábitats acuáticos. La conservación y perfeccionamiento de la gestión de corredores fluviales y las llanuras de inundación asociadas y el mantenimiento de su integridad hidrológica son fundamentales para preservar la biodiversidad dulceacuícola de Brasil y la salud de sus recursos acuáticos. [source] | ||||||||||||||||||||||||||||||||||||||||