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Journal of Phycology

Ane Cecilie Kvernvik, Clara Jule Marie Hoppe, Evelyn Lawrenz, Ondřej Prášil, Michael Greenacre, Józef Maria Wiktor, Eva Leu
Arctic microalgae experience long periods of continuous darkness during the polar night, where they are unable to photosynthesize. Despite numerous studies on overwintering strategies, such as utilization of stored energy products, formation of resting stages, reduction of metabolic rate and heterotrophic lifestyles, there have been few attempts to assess the in situ physiological state and restoration of the photosynthetic apparatus upon re-illumination. In this study, we found diverse and active marine phytoplankton communities during the polar night at 78° N...
May 3, 2018: Journal of Phycology
Maren Ziegler, Elizabeth Stone, Daniel Colman, Cristina Takacs-Vesbach, Ursula Shepherd
Large-scale environmental disturbances may impact both partners in coral host-Symbiodinium systems. Elucidation of the assembly patterns in such complex and interdependent communities may enable better prediction of environmental impacts across coral reef ecosystems. In this study, we investigated how the community composition and diversity of dinoflagellate symbionts in the genus Symbiodinium were distributed among 12 host species from six taxonomic orders (Actinaria, Alcyonacea, Miliolida, Porifera, Rhizostoma, Scleractinia) and in the reef water and sediments at Lizard Island, Great Barrier Reef before the 3rd Global Coral Bleaching Event...
April 26, 2018: Journal of Phycology
William J Henley, Michael Cobbs, Lucie Novoveská, Mark A Buchheim
Dunaliella, a commercially important chlorophyte, is globally distributed in saline habitats. Morphological species have not been definitively reconciled with phylogenetic analyses. Considerable genetic diversity continues to be discovered in new isolates, especially from soil and benthic habitats. Twenty-nine new isolates from Great Salt Lake, Utah, many from benthic or supralittoral habitats, were phylogenetically analyzed using ITS1+5.8S+ITS2 in comparison to a broad sampling of available sequences. A few new isolates align in one branch of a bifurcated monophyletic D...
April 21, 2018: Journal of Phycology
Nataliia V Annenkova, Dag Ahrén, Ramiro Logares, Anke Kremp, Karin Rengefors
Recently radiated dinoflagellates Apocalathium aciculiferum (collected in Lake Erken, Sweden), A. malmogiense (Baltic Sea) and Apocalathium aff. malmogiense (Highway Lake, Antarctica) represent a lineage with an unresolved phylogeny. We determined their phylogenetic relationships using phylotranscriptomics based on 792 amino acid sequences. Our results showed that A. aciculiferum diverged from the other two closely related lineages, consistent with their different morphologies in cell size, relative cell length and presence of spines...
April 20, 2018: Journal of Phycology
Lauren E Lees, Stacy A Krueger-Hadfield, Andrew J Clark, Elizabeth A Duermit, Erik E Sotka, Courtney J Murren
Theory predicts that the maintenance of haplodiplontic life cycles requires ecological differences between the haploid gametophytes and diploid sporophytes, yet evidence of such differences remain scarce. The haplodiplontic red seaweed Gracilaria vermiculophylla has invaded the temperate estuaries of the Northern Hemisphere, where it commonly modifies detrital and trophic pathways. In native populations, abundant hard substratum enables spore settlement, and gametophyte:tetrasporophyte ratios are approximately 40:60...
April 20, 2018: Journal of Phycology
Abdullah A Saber, Karolina Fučíková, Hilary A McManus, Graziano Guella, Marco Cantonati
The biodiversity of terrestrial algae is still grossly understudied, and African deserts in particular are barely touched in this respect. Here, four coccoid green algae from oases in the Western Desert of Egypt were characterized using a combination of morphotaxonomic, ecological and 18S rDNA data, with additional carotenoid and lipid analyses for two of the strains. Three strains were identified as affiliated with known taxa: Mychonastes sp., Asterarcys sp. (first report of this genus from a desert soil), and Stichococcus cf...
March 30, 2018: Journal of Phycology
Annalisa Caragnano, Alexandra Foetisch, Gavin W Maneveldt, Laurent Millet, Li-Chia Liu, Showe-Mei Lin, Graziella Rodondi, Claude E Payri
A multi-gene (SSU, LSU, psbA and COI) molecular phylogeny of the family Corallinaceae (excluding the subfamilies Lithophylloideae and Corallinoideae) showed a paraphyletic grouping of six monophyletic clades. Pneophyllum and Spongites were reassessed and recircumscribed using DNA sequence data integrated with morpho-anatomical comparisons of type material and recently collected specimens. We propose Chamberlainoideae subfam. nov., including the type genus Chamberlainium gen. nov., with C. tumidum comb. nov...
March 25, 2018: Journal of Phycology
Eva Rothäusler, Hannes Reinwald, Boris A López, Fadia Tala, Martin Thiel
The persistence of floating seaweeds, which depends on abiotic conditions but also herbivory, had previously been mostly tested in outdoor mesocosm experiments. In order to investigate if the obtained mesocosm results of high seaweed persistence under natural environmental conditions and under grazing pressure can be extrapolated to field situations, we conducted in situ experiments. During two summers (2007 and 2008), Macrocystis pyrifera was tethered (for 14 d) to lines in the presence and absence of the amphipod Peramphithoe femorata at three sites (Iquique, Coquimbo, Calfuco)...
March 13, 2018: Journal of Phycology
Marianna Venuleo, Mario Giordano
The diatom Phaeodactylum tricornutum was cultured in five different growth regimes to obtain cells with different composition. Pairs of populations subjected to different treatments were then mixed in a communal culture regime that differed from those of origin. After 6 h, the ratio between the two populations was verified by flow cytometry. Alterations in this ratio were found when cells previously grown at 1 mM NH4 + were mixed with GeO2 - and 0.5 mM NH4 + -grown cells. The nutritional background may thus make cells differently suited to new environmental conditions and afford advantages in terms of reproductive potential...
March 12, 2018: Journal of Phycology
Andrew McMinn, Shihong Lee
Micro glucose biosensors were used to measure net extracellular glucose produced by natural microphytobenthos and three diatom cultures (Amphora coffeaeformis, Navicula menisculus, Nitzschia longissima) from southern Tasmania, Australia. They were exposed to a light gradient in either nutrient-replete or nutrient-limiting conditions. Glucose exudation in the natural communities increased with increased light but the response in the cultures was variable. Similarly, nutrient-replete conditions elicited lower rates of glucose exudation in the natural communities but produced variable species-specific responses in the cultures...
March 7, 2018: Journal of Phycology
Kyra G Janot, Patrick T Martone
The evolution of uncalcified genicula in upright calcified corallines has occurred at least three times independently, resulting in articulated corallines within Corallinoideae, Lithophylloideae, and Metagoniolithoideae. Genicula confer flexibility to otherwise rigid thalli, and the localization of bending at discrete intervals amplifies bending stress in genicular tissue. Genicular morphology must, therefore, be balanced between maintaining flexibility while mitigating or resisting stress. Genicula in the three articulated lineages differ in both cellular construction and development, which may result in different constraints on morphology...
March 5, 2018: Journal of Phycology
Bruno Briani, Marina N Sissini, Leidson A Lucena, Manuela B Batista, Iara O Costa, José M C Nunes, Caroline Schmitz, Fernanda Ramlov, Marcelo Maraschin, Nathalie Korbee, Leonardo Rörig, Paulo A Horta, Félix L Figueroa, José B Barufi
Mycosporine-like amino acids (MAA) are ultraviolet screen substances synthesized by marine algae. The physiological function of these substances is related to cellular protection against UV radiation and as a protective mechanism against oxidative stress. These substances can be found mainly in the ocean, among red seaweeds. Its concentration in organisms has been related to ultraviolet radiation and availability of inorganic nitrogen in the environment. We start our study of MAA content in different species to understand if environmental conditions influence the concentration of MAAs in red seaweeds...
March 5, 2018: Journal of Phycology
Adi Volpert, Shiri Graff van Creveld, Shilo Rosenwasser, Assaf Vardi
Diatoms are one of the key phytoplankton groups in the ocean, forming vast oceanic blooms and playing a significant part in global primary production. To shed light on the role of redox metabolism in diatom's acclimation to light-dark transition and its interplay with cell fate regulation, we generated transgenic lines of the diatom Thalassiosira pseudonana that express the redox-sensitive green fluorescent protein targeted to various subcellular organelles. We detected organelle-specific redox patterns in response to oxidative stress, indicating compartmentalized antioxidant capacities...
March 5, 2018: Journal of Phycology
Maja Mejdandžić, Sunčica Bosak, Teofil Nakov, Elizabeth Ruck, Sandi Orlić, Marija Gligora Udovič, Petra Peharec Štefanić, Igor Špoljarić, Gordan Mršić, Zrinka Ljubešić
The diatom genus Entomoneis is known from the benthos and plankton of marine, brackish, and freshwaters. Entomoneis includes diatoms with a bilobate keel elevated above the valve surface, a sigmoid canal raphe, and numerous girdle bands. Owing mostly to the scarcity of molecular data for a diverse set of species, the phylogeny of Entomoneis has not been investigated in depth. The few previous studies that included Entomoneis were focused on broader questions and the available data were from a small number of either unidentified Entomoneis or well-known species (e...
April 2018: Journal of Phycology
Hong Chang Lim, Suh Nih Tan, Sing Tung Teng, Nina Lundholm, Emma Orive, Helena David, Sonia Quijano-Scheggia, Sandric Chee Yew Leong, Matthias Wolf, Stephen S Bates, Po Teen Lim, Chui Pin Leaw
Analyses of the mitochondrial cox1, the nuclear-encoded large subunit (LSU), and the internal transcribed spacer 2 (ITS2) RNA coding region of Pseudo-nitzschia revealed that the P. pseudodelicatissima complex can be phylogenetically grouped into three distinct clades (Groups I-III), while the P. delicatissima complex forms another distinct clade (Group IV) in both the LSU and ITS2 phylogenetic trees. It was elucidated that comprehensive taxon sampling (sampling of sequences), selection of appropriate target genes and outgroup, and alignment strategies influenced the phylogenetic accuracy...
April 2018: Journal of Phycology
Chelsea D Villanueva, Petr Hašler, Petr Dvořák, Aloisie Poulíčková, Dale A Casamatta
Cyanolichens are an assemblage of fungi and cyanobacteria from diverse, cosmopolitan habitats. Typically composed of a single species of cyanobacterium, with or without another eukaryotic alga, here we present two novel cyanobionts isolated from an undescribed tripartite lichen. This endolithic lichen was isolated from a granite cemetery tombstone from Jacksonville, FL, and contains two potentially nitrogen-fixing cyanobionts. Employing a total evidence approach, we characterized the cyanobionts using molecular (the 16S rDNA and ITS gene region), morphological, and ecological data...
April 2018: Journal of Phycology
Ga Hun Boo, Line Le Gall, Il Ki Hwang, Kathy Ann Miller, Sung Min Boo
The genus Ptilophora currently includes 16 species occurring mostly in subtidal habitats of the Indo-Pacific Ocean, but its global diversity and biogeography are poorly understood. We analyzed mitochondrial cox1, plastid rbcL and plastid psbA sequences from specimens collected in southern Madagascar during the 2010 Atimo Vatae expedition and studied their morphologies. Both morphological and molecular data sets demonstrated the presence of five species in southern Madagascar: Ptilophora hildebrandtii, P. pterocladioides, and three new species described here, P...
April 2018: Journal of Phycology
Rebecca Guenther, Kevin Miklasz, Emily Carrington, Patrick T Martone
Early life stages of marine organisms are predicted to be vulnerable to ocean acidification. For macroalgae, reproduction and population persistence rely on spores to settle, adhere and continue the algal life cycle, yet the effect of ocean acidification on this critical life stage has been largely overlooked. We explicitly tested the biomechanical impact of reduced pH on early spore adhesion. We developed a shear flume to examine the effect of reduced pH on spore attachment time and strength in two intertidal rhodophyte macroalgae, one calcified (Corallina vancouveriensis) and one noncalcified (Polyostea robusta)...
April 2018: Journal of Phycology
Masahiko Idei, Shinya Sato, Nagumo Tamotsu, David G Mann
Diploneis species have perhaps the most complex valve structure among pennate diatoms. The development of this structure was studied in Diploneis smithii and begins with the formation of a primary band, which then develops secondary arms at both poles and the center, as in the classic Chiappino-Volcani model of raphid diatom ontogeny. Spine-like projections grow out from the primary band and secondary arms to establish the transapical ribs (virgae) of the mature valve and themselves develop spines, which are spaced first oppositely and then alternately and fuse with each other to delimit the stria pores...
April 2018: Journal of Phycology
Nicole Sausen, Veronica Malavasi, Michael Melkonian
In the present study, three new strains of the rare volvocalean green alga Lobomonas were isolated from field-collected samples, one from Sardinia (Italy) and two from Argentina, and comparatively studied. The Sardinian and one of the Argentinian strains were identified as Lobomonas francei, the type species of the genus, whereas the second Argentinian strain corresponded to L. panduriformis. Two additional nominal species of Lobomonas from culture collections (L. rostrata and L. sphaerica) were included in the analysis and shown to be morphologically and molecularly identical to the L...
April 2018: Journal of Phycology
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