Species within the green algal order, Cladophorales, have an unconventional plastome structure where individual coding regions or small numbers of genes occur as linear single‐stranded DNAs folded into hairpin structures. Another group of photosynthetic organisms with an equivalently reduced chloroplast genome are the peridinin dinoflagellates of the Alveolata eukaryotic lineage whose plastomes are

The determination of the ploidy level of an organism is a prerequisite for studies of evolution, cellular function, and genomic construction. Identification of the ploidy of the economically important red algae Gracilariopsis lemaneiformis has been hindered by its small genome and large number of chromosomes. Therefore, in the current study, PloidyNGS, a tool that calculates the number of reads supporting

Sea‐ice algae contribute up to 25% of the primary productivity of polar seas and seed large‐scale ice‐edge blooms. Fluctuations in temperature, salinity, and light associated with the freeze/thaw cycle can significantly impact the photophysiology of ice‐associated taxa. The effects of multiple co‐stressors (i.e., freezing temperature and high brine salinity or sudden high light exposure) on the photophysiology

We evaluated the life cycle of Leathesia marina through molecular analyses, culture studies, morphological observations and ploidy measurements. Macroscopic sporophytes were collected from two localities in Atlantic Patagonia and were cultured under long day (LD) and short day (SD) conditions. Molecular identification of the microscopic and macroscopic phases was performed through the cox 3 and rbc

Phytohormones are pivotal signalling compounds in higher plants, in which they exert their roles intracellularly, but are also released for cell‐to‐cell communication. In unicellular organisms, extracellularly released phytohormones can be involved in chemical crosstalk with other organisms. However, compared to higher plants, hardly any knowledge is available on the roles of phytohormones in green

Dissolved organic carbon (DOC) is an important source of carbon and energy for microbes, but whether it can be used by phytoplankton has not been systematically studied, and the underlying molecular metabolism remains poorly understood. Here we investigated the ability of phytoplankton to utilize glycerol as a representative of DOC. The widespread presence and expression of glycerol transporter genes

Twenty-six cultures of the harmful marine dinoflagellate Karlodinium, isolated from Japanese and Philippine coastal waters, were examined using LM, SEM and molecular phylogeny inferred from ITS and LSU rDNA. Seven Karlodinium species (6 from Japan and 4 from Philippines), K. australe, K. ballantinum, K. decipiens, K. gentienii, K. veneficum, K. zhouanum, and a novel species Karlodinium azanzae sp.

Microalgae exhibit extensive potential for counteracting imminent challenges in the nutraceuticals, pharmaceutical, and biomaterials sectors but lack economic viability. Biotechnological systems for contamination control could advance the economic viability of microalgal feedstock, but the selection of suitable strains that sustainably promote microalgal productivity remains challenging. In the present

Nitric oxide (NO) is widely recognized as an important transmitter molecule in biological systems, from animals to plants and microbes. However, the role of NO in marine photosynthetic microbes remains unclear and even less is known about the role of this metabolite in Antarctic sea-ice diatoms. By using a combination of microsensors, microfluidic chambers and artificial sea-ice tanks, a basic mechanistic

Morphological and molecular features were analyzed for species of Phacus to better understand the phylogenetic relationships among them and establish the taxonomy; the phylogenetic analyses were based on nSSU rDNA; the research resulted in 55 new sequences. The study included species available in algae collections and those isolated directly from the environment in Poland and Czech Republic. As a result

To test the proposal that rotifers release one or more chemical microalgal growth inhibitors in addition to devouring the microalgal cells, the effects of different concentrations of filtered, bacteria-free, rotifer culture filtrate (RCF) on the growth and physiological parameters of Chlorella sp., and the response of Chlorella sp. at different starting cell densities to 10% RCF were studied. The results

The polyphasic approach has been widely applied in cyanobacterial taxonomy which frequently led to additions to the species inventory. Increasing our knowledge about species and the habitats they were isolated from enables new insights into the ecology of newly established genera and species allowing speculations about the ecological niche of taxa. Here, we are describing three new species belonging

Membrane permeabilities to CO2 and HCO3 - constrain the function of CO2 concentrating mechanisms that algae use to supply inorganic carbon for photosynthesis. In diatoms and green algae, plasma-membranes are moderately to highly permeable to CO2 but effectively impermeable to HCO3 - . Here, CO2 and HCO3 - membrane permeabilities were measured using an 18 O-exchange technique on two species of haptophyte

Uptake dynamics of dissolved inorganic phosphate (DIP) and dissolved inorganic nitrate (DIN) in young Palmaria palmata (n=49), cultivated in a range of DIP concentrations (0.0-6.0 µmol · L-1 ) and non-limiting DIN concentration (50 µmol · L-1 ) under fully controlled laboratory conditions, were quantified in a 'pulse-and-chase' approach over 5 weeks. Two different uptake rates were specified: (1) surge

Saccharina japonica is a brown macroalga that has been commercially cultivated in China for almost a century. As a natural raw material, it is widely used in the food and pharmaceutical industries, and it may potentially be useful for biofuel production. However, little is known about the genes involved in carbohydrate biosynthesis and their regulation is less well understood. In this study, the analysis

Lake snow, caused by the freshwater centric diatom Lindavia intermedia, has become problematic in several large, oligotrophic New Zealand lakes over the past decade. Macroaggregates produced by L. intermedia foul fishing lines, intake screens, and water filters, and have a negative impact on recreational values. It was confirmed that the fibers constituting lake snow are composed of chitin, two chitin

Ceratium furcoides is an invasive freshwater dinoflagellate that in the last three decades has expanded its geographic distribution in South America, being recently found in Paraná River floodplain (Argentina). Despite growing concern about the presence and impacts of this invader, information regarding genetic diversity in the southern hemisphere is missing. This work constitutes the first phylogenetic

The cosmopolitan red algal genus Pyropia sensu lato is the most speciose of the bladed Bangiales genera. In a major revision of the Bangiales, Pyropia was resurrected from Porphyra, although there was evidence at the time that species of Pyropia could be separated into several genera. Subsequent global phylogenetic analyses continued to resolve species assigned to Pyropia into several major clades

The uptake and conversion of a free-living cyanobacterium into a photosynthetic organelle by the single-celled Archaeplastida ancestor helped transform the biosphere from low to high oxygen. There are two documented, independent cases of plastid primary endosymbiosis. The first is the well-studied instance in Archaeplastida that occurred ca. 1.6 billion years ago, whereas the second occurred 90-140

Since the first phylogenetic study of the order Batrachospermales, Batrachospermum was shown to be paraphyletic. Subsequently, sections of the genus have been methodically investigated using DNA sequences and morphology in order to propose new genera and delineate species. Batrachospermum section Turfosa is the last section with multiple species yet to be examined. New sequence data of specimens from

A pink to red-pigmented cryptophyte of undetermined taxonomic affinity was isolated and cloned from two seasonally ice-covered. meromictic, saline Antarctic aquatic environments: Bayly Bay (BB) and Ace Lake (AL). The clones shared a number of morphological and ultrastructural similarities with other cryptomonad genera, which confounded identification by light and electron microscopy. Cellular pigments

Distributed in tropical and warm-temperate waters worldwide, Lobophora species are found across the Greater Caribbean (i.e., Caribbean sensu stricto, Gulf of Mexico, Florida, the Bahamas, and Bermuda). We presently discuss the diversity, ecology, biogeography, and evolution of the Greater Caribbean Lobophora species based on previous studies and an extensive number of samples collected across the eastern

The Arctic Ocean is a unique ecosystem hosting a biodiversity that has not yet been elucidated in full detail. There is increasing evidence that there are more kelp species constricted to Arctic/sub-Arctic habitats hitherto not well investigated, such as Hedophyllum nigripes, which is morphologically very similar to cold-temperate Laminaria digitata. Hedophyllum nigripes was originally described as

The eukaryotic green microalga Tetraselmis suecica is commonly used for aquaculture purposes because of its high stress tolerance and ease of culture in a wide spectrum of environments; they are therefore suitable candidates for biotechnology applications. To date, no data are available regarding chloroplast transformation vectors based on specific endogenous promoters and homologous targeting regions

The Symbiodiniaceae are a family of marine dinoflagellates known mostly for their endosymbiotic interactions with invertebrates and protists, but facultatively and exclusively free-living life histories in this family are also evident. A recent systematic revision of the Symbiodiniaceae replaced the clade-based nomenclature of seven divergent lineages of "Symbiodinium" sensu lato with one based on

Worldwide, macroalgae have invaded near-shore marine ecosystems. However, their haplodiplontic life cycles have complicated efforts to predict patterns of growth and spread, particularly since most theoretical predictions are derived from diplontic taxa (i.e., animals). To complete one revolution of the life cycle, two separate ploidy stages, often including separate haploid sexes, must pass through

The biological processes involved in the preservation, viability, and revival of long-term dormant dinoflagellate cysts buried in sediments remain unknown. Based on studies of plant seed physiology, we tested whether the revival of ancient cysts preserved in century-old sediments from the Bay of Brest (France) could be stimulated by melatonin and gibberellic acid, two molecules commonly used in seed

Geographic variation of phenotypic traits affects the capacity of species to withstand and adapt to environmental stress. Here, we examined how geographic origin influences UV-stress tolerance of the red seaweeds Chondracanthus chamissoi and Gelidium lingulatum distributed along the South-East Pacific coast between 20° S and 42° S. Seaweeds from 6 (C. chamissoi) and 5 (G. lingulatum) populations were

The class Eustigmatophyceae includes mostly coccoid, freshwater algae, although some genera are common in terrestrial habitats and two are primarily marine. The formal classification of the class, developed decades ago, does not fit the diversity and phylogeny of the group as presently known and is in urgent need of revision. This study concerns a clade informally known as the Pseudellipsoidion group

Detailed morphological documentation is provided for established Proschkinia taxa, including the generitype, P. bulnheimii, and P. complanata, P. complanatula, P. complanatoides and P. hyalosirella, and six new species. All established taxa are characterized from original material from historical collections. The new species described in this paper (P. luticola, P. staurospeciosa, P. impar, P. modesta

Sargassum horneri is a habitat-forming species in the Northwest Pacific and an important contributor to seaweed rafts. In this study, 131 benthic samples and 156 floating samples were collected in the Yellow Sea and East China Sea (ECS) to test the effects of seaweed rafts on population structure and connectivity. Our results revealed high levels of genetic diversity in both benthic and floating samples

The domesticated marine microalga Diacronema lutheri is of great interest for producing various highly valuable molecules like lipids, particularly long-chain polyunsaturated fatty acids (LC-PUFA). In this study, we investigated the impact of phosphorus (P) and nitrogen (N) starvation on growth, carbon fixation (photosynthetic activity) and partitioning, and membrane lipid remodeling in this alga during

Comparative organelle genome studies of parasites can highlight genetic changes that occur during the transition from a free-living to a parasitic state. Our study focuses on a poorly studied group of red algal parasites, which are often closely related to their red algal hosts and from which they presumably evolved. Most of these parasites are pigmented and some show photosynthetic capacity. Here

With the advent of more comprehensive research into the microbiome and interactions between animals and their microbiota, new solutions can be applied to address conservation challenges such as husbandry and medical care of captive animals. Although studies on epizoic algae are relatively rare, and the function and role of those mainly photosynthetic organisms in the animal microbiome is not well understood

The main aims of this work were to assess phylogenetic relationships of the trentepohlialean photobionts in tropical, mainly sterile, lichens collected in Bolivia, to examine their genetic diversity, host specificity, and the impact of habitat factors on the occurrence of Trentepohliales. Based on rbcL marker analysis, we constructed a phylogenetic tree with eight major clades of Trentepohliales, of

Samples of Pithophoraceae, collected in diverse freshwater and damp terrestrial habitats from tropical and subtropical China, were characterized morphologically and ultrastructurally, and their phylogenetic position was determined based on nuclear ribosomal DNA sequences. Our phylogenetic analysis resolved a novel lineage of Pithophoraceae, sister to Aegagropilopsis. Based on our phylogenetic results

The haptophyte Phaeocystis antarctica is endemic to the Southern Ocean, where iron supply is sporadic and its availability limits primary production. In iron fertilization experiments, P. antarctica showed a prompt and steady increase in cell abundance compared to heavily silicified diatoms along with enhanced colony formation. Here we utilized a transcriptomic approach to investigate molecular responses

Temperature and nutrient supply are key factors that control phytoplankton ecophysiology, but their role is commonly investigated in isolation. Their combined effect on resource allocation, photosynthetic strategy, and metabolism remains poorly understood. To characterize the photosynthetic strategy and resource allocation under different conditions, we analyzed the responses of a marine cyanobacterium

Chaetoceros debilis is considered one of the most abundant and widespread diatoms in the coastal marine phytoplankton, and is often used in research studies ranging from ecophysiology and molecular biology to oceanography and aquaculture. To clarify the species delineation of C. debilis and explore the diversity among C. debilis sensu lato taxa, monoclonal strains were established from different geographical

The genus Paragymnodinium currently includes two species, P. shiwhaense and P. stigmaticum that are characterized by mixotrophic nutrition and the possession of nematocysts. In this study, two new dinoflagellates belonging to this genus were described based on observations using LM, SEM and TEM together with a molecular analysis. Cells of P. asymmetricum sp. nov., isolated from Nha Trang beach, Vietnam

Several strains of terrestrial algae isolated from biological soil crusts of Germany and Ukraine were identified by morphological methods as the widely distributed species Dictyosphaerium minutum (= Dictyosphaerium chlorelloides). Investigation of the phylogeny showed their position unexpectedly outside of Chlorellaceae (Trebouxiophyceae) and distantly from Chlorella chlorelloides, to which this taxon

We performed a comparison of molecular and morphological diversity in a freshwater colonial genus Synura (Chrysophyceae, Stramenopiles), using the island of Newfoundland (Canada) as a case study. We examined the morphological species diversity in collections from 79 localities, and compared these findings to diversity based on molecular characters for 150 strains isolated from the same sites. Of 27

The cryptophyte Teleaulax amphioxeia is a source of plastids for the ciliate Mesodinium rubrum and both organisms are members of the trophic chain of several species of Dinophysis. It is important to better understand the ecology of organisms at the first trophic levels before assessing the impact of principal factors of global change on Dinophysis spp. Therefore, combined effects of temperature, irradiance

We assessed the relative influence of ecoregional features in explaining diatom distribution in the Orinoco river basin. Ecoregions in the Colombian Orinoco can be seen as imprints of the evolutionary history of the basin, for their current biodiversity and physiographic features are the result of the geological and climatic shifts that have occurred since the Tertiary. Thus, they represent an ideal

Populations of many Mediterranean marine species show a strong phylogeographic structure, but the knowledge available for native seaweeds is limited. We investigated the genetic diversity of the green alga Halimeda tuna based on two plastid markers (tufA gene and a newly developed amplicon spanning five ribosomal protein genes and intergenic spacers, the rpl2-rpl14 region). The tufA sequences showed

Mixotrophic algae that combine photoautotrophy with phagotrophy in a single cell are prevalent in marine ecosystems. Here, we assessed the ability of food ingestion in coccolithophores, an important group of calcifying haptophytes inhabiting the oceans. We tested four species from different coccolithophore lineages (Emiliania huxleyi, Calcidiscus leptoporus, Coccolithus braarudii, and Calyptrosphaera

Survival of coral reef-associated Symbiodiniaceae is vital to maintain the healthy coral community in coral reefs. However, knowledge about cultivation of free-living or symbiotic Symbiodiniaceae has been limited. In this study, the response surface methodology was applied firstly to optimize the medium for Effrenium voratum. The results revealed that the impacts of nutrient components on algal growth

Due to climate change, the incidence of marine heat waves (MHW s) has increased, yet their effects on seaweeds are still not well understood. Adult sporophytes of Macrocystis pyrifera , the species forming the iconic giant kelp forests, can be negatively affected by thermal stress and associated environmental factors (e.g., nutrient depletion, light deprivation); however, little is known about the

ON THE COVER: Mosaic of euglenids: Phacus salinus (egg‐shaped cells), Lepocinclis oxyuris (cylindrical specimens), Trachelomonas sp. (brown cells), Phacus longicauda with a distinctive, circular paramylon grain

Dissolved organic carbon (DOC) released by macroalgae is important in the context of coral reef degradation as it contributes to coral mortality by promoting bacterial metabolism on the coral surface. Using experimental carbon dioxide (CO2 ) manipulations in outdoor flow-through tanks, we found that seawater CO2 enrichment enhances daily net DOC release in a range of macroalgal species in the Great

Prorocentrum minimum is a potentially toxic marine dinoflagellate that often forms massive blooms in estuarine and coastal sea waters. In this study, the life cycle of P. minimum was investigated and sexual reproduction in culture was described for the first time. Morphology of the mitotic stages was revised and several distinguishing features from sexual steps were described. The sexual reproductive

Despite worldwide proliferation of the genus Caulerpa and subsequent effects on benthic communities, little is known about the nutritional physiology of the Caulerpales. Here, we investigated the uptake rates of ammonium, nitrate, amino acids, and phosphate through the fronds and rhizoids + stolon, the internal translocation of nitrogen, and developed a nitrogen budget for the rapidly spreading Caulerpa

In response to a comment in this issue on our proposal of new terminology to distinguish red algal parasites, we clarify a few key issues. The terms adelphoparasite and alloparasite were previously used to identify parasites that infected close or distant relatives. However, most red algal parasites have only been studied morphologically, and molecular tools have shown that these binary terms do a

Marine benthic dinoflagellates are interesting not only because some epiphytic genera can cause harmful algal blooms but also for understanding dinoflagellate evolution and diversification. Our understanding of their biodiversity is far from complete, and many thecate genera have unusual tabulation patterns that are difficult to relate to the diverse known phytoplankton taxa. A new sand‐dwelling genus

Phaeocystis antarctica is an important primary producer in the Southern Ocean and plays roles in sulfur cycles through intracellular production of dimethylsulfoniopropionate (DMSP), a principal precursor of dimethyl sulfide (DMS). Haptophytes, including P. antarctica, are known to produce more DMSP than other phytoplankton groups such as diatoms and green algae, suggesting their important contribution

Here we elaborate the underlying responses of photosynthesis and related processes in the thermotolerant microalga Micractinium sp. acclimated to limiting and saturating irradiances combined with elevated temperatures, by using a novel computer‐controlled multi‐sensor system which allows monitoring online values of oxygen exchange in photosynthesis and respiration with high accuracy. Micractinium sp

The following article from the Journal of Phycology, "Carotenoids, Mycosporine-Like Amino Acid Compounds, Phycobiliproteins, And Scytonemin In The Genus Scytonema (Cyanobacteria): A Chemosystematic Study," submitted by Antonia D. Asencio, and published online on August 22, 2011 on Wiley Online Library (http://www.wileyonlinelibrary.com), has been retracted by agreement between the journal Editor, Robert

ON THE COVER: Durvillaea bull‐kelp is a keystone genus in shallow waters of the Southern Hemisphere. In New Zealand, up to three Durvillaea species can grow sympatrically. Here, on a steep rock face at Second Beach in Otago, D. poha (with wider, paler blades and shorter, stouter stipes) grows a little above D. antarctica in the intertidal, and D. willana (not visible) grows subtidally. Molecular and

Comparative algal genomics often relies on predicted genes from de novo assembled genomes. However, the artifacts introduced by different gene-prediction approaches, and their impact on comparative genomic analysis remain poorly understood. Here, using available genome data from six dinoflagellate species in the Symbiodiniaceae, we identified methodological biases in the published genes that were predicted

A redefinition of the cyanobacterial lineage has been proposed based on phylogenomic analysis of distantly related nonphototrophic lineages. We define Cyanobacteria here as "Organisms in the domain bacteria able to carry out oxygenic photosynthesis with water as an electron donor and to reduce carbon dioxide as a source of carbon, or those secondarily evolved from such organisms."