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Journal of Phycology

Takashi Nakada, Masaru Tomita
New strains of wall-less unicellular volvocalean flagellate were isolated from a freshwater environment in Japan. Observations of the alga, described here as Hapalochloris nozakii Nakada, gen. et sp. nov., were made under light, fluorescence, and electron microscopes. Each vegetative cell had two flagella, four contractile vacuoles, and a spirally furrowed cup-shaped chloroplast with an axial pyrenoid, and mitochondria located in the furrows. Based on the morphology, H. nozakii was distinguished from other known wall-less volvocalean flagellates...
October 21, 2016: Journal of Phycology
Gang Li, David Talmy, Douglas A Campbell
Light drives phytoplankton productivity, so phytoplankton must exploit variable intensities and durations of light exposure, depending upon season, latitude and depth. We analyzed the growth, photophysiology and composition of small, Thalassiosira pseudonana, and large, Thalassiosira punctigera, centric diatoms from temperate, coastal marine habitats, responding to a matrix of photoperiods and growth light intensities. T. pseudonana showed fastest growth rates under long photoperiods and low to moderate light intensities, while the larger T...
October 18, 2016: Journal of Phycology
Tatyana Darienko, Lydia Gustavs, Thomas Pröschold
The genera Elliptochloris and Pseudochlorella were erected for Chlorella-like green algae producing two types of autospores and cell packages, respectively. Both genera are widely distributed in different soil habitats, either free-living or as photobionts of lichens. The species of these genera are often difficult to identify because of the high phenotypic plasticity and sometimes lack of characteristic features. The taxonomic and nomenclatural status of these species therefore remains unclear. In this study, 34 strains were investigated using an integrative approach...
October 13, 2016: Journal of Phycology
Boris A López, Erasmo C Macaya, Fadia Tala, Florence Tellier, Martin Thiel
Dispersal on floating seaweeds depends on availability, viability and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°-42°S)...
October 13, 2016: Journal of Phycology
Bernabé Santelices, Alejandra V González, Jessica Beltrán, Verónica Flores
Chimerism is produced by the somatic fusion of two or more genetically distinct conspecific individuals. In animals, the main cost of fusion is competition between genetically different cell lineages and the probability of original cell-line replacement by more competitive invasive lines, which limits its natural frequency (3-5%). In red and brown seaweeds, chimerism is widespread (27-53%), seemingly without the negative outcomes described for animals. The rigidity of cell walls in macroalgae prevents cell motility and invasions...
October 7, 2016: Journal of Phycology
Stefanie Raddatz, Tamar Guy-Haim, Gil Rilov, Martin Wahl
Human induced ocean warming and acidification have received increasing attention over the past decade and are considered to have substantial consequences for a broad range of marine species and their interactions. Understanding how these interactions shift in response to climate change is particularly important with regard to foundation species, such as the brown alga Fucus vesiculosus. This macroalga represents the dominant habitat former on coastal rocky substrata of the Baltic Sea, fulfilling functions essential for the entire benthic community...
October 6, 2016: Journal of Phycology
Ladd E Johnson, Robert T Paine
Coralline algae are conspicuous members of many marine assemblages, especially those characterized by intense grazing pressure. We explored whether articulated species, especially Corallina vancouveriensis, depend on grazing invertebrates to both establish and flourish in an exposed rocky intertidal setting, and whether this plant-grazer relationship varied over more than three orders of magnitude (≈100 μm to >300,000 μm). Three experimental manipulations, supplemented by observations on recruitment, demonstrated that (1) C...
October 6, 2016: Journal of Phycology
Christopher D G Harley
Fifty years ago, Robert Treat Paine published his seminal paper on food web complexity and biodiversity (Paine 1966). In this work, Paine used sea stars to illustrate how relationships among species were key determinants of emergent ecological patterns, and in so doing he injected a healthy dose of testable mechanism into a field that was largely phenomenological at the time. The example of the sea star Pisaster ochraceus as a keystone predator (Paine 1966, 1969) remains a standard example in Ecology textbooks, and undergraduates who take ecology courses today are likely to associate the name Paine with starfish...
October 6, 2016: Journal of Phycology
Ravi S Pandey, Garima Saxena, Debashish Bhattacharya, Huan Qiu, Rajeev K Azad
Identification of horizontal gene transfers (HGTs) has primarily relied on phylogenetic tree based methods, which require a rich sampling of sequenced genomes to ensure a reliable inference. Because the success of phylogenetic approaches depends on the breadth and depth of the database, researchers usually apply stringent filters to detect only the most likely gene transfers in the genomes of interest. One such study focused on a highly conservative estimate of trans-domain gene transfers in the extremophile eukaryote, Galdieria sulphuraria (Galdieri) Merola (Rhodophyta), by applying multiple filters in their phylogenetic pipeline...
October 5, 2016: Journal of Phycology
Chris Jackson, Eric D Salomaki, Christopher E Lane, Gary W Saunders
If ever there were "charismatic megaflora" of the sea, the Laminariales (kelp) would undoubtedly meet that designation. From the Northeast Pacific kelp forests, to the less diverse but nonetheless dense kelp beds ranging from the Arctic to the cold temperate waters of the Southern Hemisphere, kelp provide habitat structure and food for a variety of productive marine systems. Consequently, kelp are well represented in the literature, however, understanding their evolution has proven challenging. We used a 152-gene phylogenomics approach to better resolve the phylogeny of the "derived" kelp families (viz...
October 5, 2016: Journal of Phycology
Jeffery R Hughey, Max H Hommersand, Paul W Gabrielson, Kathy Ann Miller, Timothy Fuller
Next generation sequence data were generated and used to assemble the complete plastomes of the holotype of Membranoptera weeksiae, the neotype (designated here) of M. tenuis, and a specimen examined by Kylin in making the new combination M. platyphylla. The three plastomes were similar in gene content and length and showed high gene synteny to Calliarthron, Grateloupia, Sporolithon, and Vertebrata. Sequence variation in the plastome coding regions were 0.89% between M. weeksiae and M. tenuis, 5.14% between M...
September 30, 2016: Journal of Phycology
Shelby E McIlroy, Phillip Gillette, Ross Cunning, Anke Klueter, Tom Capo, Mary Alice Coffroth
For many coral species, the obligate association with phylogenetically diverse algal endosymbiont species is dynamic in time and space. Here, we used controlled laboratory inoculations of newly settled, aposymbiotic corals (Orbicella faveolata) with two cultured species of algal symbiont (Symbiodinium microadriaticum and S. minutum) to examine the role of symbiont identity on growth, survivorship, and thermal tolerance of the coral holobiont. We evaluated these data in the context of Symbiodinium photophysiology for nine months post-settlement and also during a 5-day period of elevated temperatures...
September 30, 2016: Journal of Phycology
Daniel C O Thornton, Jie Chen
Exopolymer particles are found throughout the ocean and play a significant biogeochemical role in carbon cycling. Transparent exopolymer particles (TEP) are composed of acid polysaccharides and Coomassie staining particles (CSP) are proteins. TEP have been extensively studied in the ocean, while CSP have been largely overlooked. The objective of this research was to determine the role of stress and cell permeability in the formation of TEP and CSP. The diatom Thalassiosira weissflogii and cyanobacterium Synechococcus elongatus were grown in batch cultures and exposed to hydrogen peroxide (0, 10, and 100 μM) as an environmental stressor...
September 30, 2016: Journal of Phycology
Li Huan, Wenhui Gu, Shan Gao, Guangce Wang
Free-floating Ulva prolifera is one of the causative species of green tides. When green tides occur, massive mats of floating U. prolifera thalli accumulate rapidly in surface seawater, with daily growth rates as high as 56%. The upper thalli of the mats experience environmental changes such as the change of carbon source, high salinity and desiccation. In this study, the photosynthetic performances of PSI and PSII in U. prolifera thalli exposed to different atmospheric carbon dioxide (CO2 ) levels were measured...
September 29, 2016: Journal of Phycology
Laura Prioretti, Mario Giordano
The Sulfate Facilitation Hypothesis suggests that changes in ocean sulfate concentration influenced the rise to dominance of phytoplankton species of the red lineage. The mechanistic reasons for this phenomenon are not yet understood. We thus started to address this question by investigating the differences in S utilization by algae of the green and red lineages and in cyanobacteria cultured in the presence of either 5 mmol. L(-1) (approximately equivalent to Paleozoic ocean concentrations) or 30 mmol. L(-1) (corresponding to post-Mesozoic/extant concentrations) sulfate...
September 22, 2016: Journal of Phycology
Pilar Garcia-Jimenez, Olegario Brito-Romano, Rafae Robaina R
Here we highlight the effects of methyl jasmonate (MeJa) on cystocarp development in the red macroscopic alga Grateloupia imbricata Holmes. In G. imbricata, jasmonate release is related to the reproductive state, as fertile thalli (i.e., those that have cystocarps) released significant amounts of this volatile compound (1.27 ± 0.20 mM (•) mg fw(-1) (•) h(-1) ) compared to infertile thalli (0.95 ± 0.12 mM (•) mg fw (-1) (•) h(-1) ). Treating G. imbricata thalli with MeJa revealed a significant increase in cystocarp number (1...
September 19, 2016: Journal of Phycology
Stefano Accoroni, Tiziana Romagnoli, Antonella Penna, Samuela Capellacci, Patrizia Ciminiello, Carmela Dell'Aversano, Luciana Tartaglione, Marie Abboud-Abi Saab, Valentina Giussani, Valentina Asnaghi, Mariachiara Chiantore, Cecilia Totti
The new benthic toxic dinoflagellate Ostreopsis fattorussoi sp. nov. is described from eastern Mediterranean Sea Lebanon and Cyprus coasts, supported by morphological and molecular data. The plate formula, Po, 3', 7'', 6c, 7s, 5''', 2'''', is typical for the Ostreopsis genus. It differs from all other Ostreopsis species in that i) the curved suture between plates 1' and 3' makes them approximately hexagonal, ii) the 1' plate lies in the left-half of the epitheca and is obliquely orientated leading to a characteristic shape of plate 6''...
September 16, 2016: Journal of Phycology
Mattia Pierangelini, John A Raven, Mario Giordano
This work originates from three facts: 1) changes in CO2 availability influence metabolic processes in algal cells. 2) Spatial and temporal variations of nitrogen availability cause repercussions on phytoplankton physiology. 3) Growth and cell composition are dependent on the stoichiometry of nutritional resources. In this study we assess whether the impact of rising pCO2 is influenced by N availability, through the impact that it would have on the C/N stoichiometry, in condition of N sufficiency. Our experiments used the dinoflagellate Protoceratium reticulatum, which we cultured under three CO2 regimes (400, 1000 and 5000 ppmv, pH of 8...
September 14, 2016: Journal of Phycology
Sabrina C Lachmann, Stephen C Maberly, Elly Spijkerman
The effect of CO2 supply is likely to play an important role in algal ecology. Since inorganic carbon (Ci ) acquisition strategies are very diverse among microalgae and Ci availability varies greatly within and among habitats, we hypothesized that Ci acquisition depends on the pH of their preferred natural environment (adaptation) and that the efficiency of Ci uptake is affected by CO2 availability (acclimation). To test this, four species of green algae originating from different habitats were studied. PH-drift and Ci uptake kinetic experiments were used to characterize Ci acquisition strategies and their ability to acclimate to high and low CO2 conditions and high and low pH was evaluated...
September 14, 2016: Journal of Phycology
Yinsui Zheng, James T Dillon, Yifan Zhang, Yongsong Huang
Alkenones (C37 to C40 ) are highly specific biomarkers produced by certain haptophyte algae in ocean and lacustrine environments and have been widely used for paleoclimate studies. Unusual shorter-chain alkenones (e.g., C35 and C36 ) have been found in environmental and culture samples but the origin and structures of these compounds are much less understood. The marine alkenone producer, Emiliania huxleyi CCMP2758 strain was reported with abundant C35:2 Me (∆(12, 19) ) alkenone when cultured at 15°C (Prahl et al...
August 30, 2016: Journal of Phycology
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