Search

Settlement induction potential of two red algae, Sahlingia subintegra and Rhodosorus marinus, and one green macroalgae, Ulvella leptochaete was examined to identify potential alternative algal species to improve reliability and reproducibility of Haliotis tuberculata sp. settlement. CCA was used as a positive control. Settlement rates, post-larval survival and growth of Haliotis tuberculata sp. were evaluated for different algal species tested. Results showed that Sahlingia subintegra induced significantly higher settlement rates (58.17 ± 12.71%) compared to CCA, Ulvella leptochaete and Rhodosorus marinus. In all treatments, post-larvae were weekly fed a mix of diatoms (Amphora sp., and Navicula incerta). At four weeks post settlement, post-larval survival rates were significantly higher on CCA and Sahlingia subintegra substrates compared to the other two algal species tested. However, at four and five weeks post settlement there were no significant differences in post-larval shell length and growth rates between CCA and Sahlingia subintegra substrates. These findings suggest that Sahlingia subintegra could be a promising alternative red macroalgae providing settlement cue for abalone hatchery stages, particularly for Haliotis tuberculata sp. and could contribute to improve abalone breeding techniques through the selection of alternative settlement substrates that could be easily managed in abalone farms environments. [ABSTRACT FROM AUTHOR] more...

The marine red algae Kappaphycus alvarezii (KA), commonly known as cottonii, is a valuable resource with diverse applications. Research has primarily focused on its primary metabolites such as amino acids, proteins, plant hormones etc. Additionally, KA also produces secondary metabolites under stress, some of which exhibit antioxidant and antibacterial properties. This review provides a comprehensive overview of recent in vitro and in vivo research on KA, delving into their therapeutic effects and potential pharmaceutical applications. The study followed a through literature survey in three databases. From the obtained literature, the studies fitting the criteria were reviewed. The study explores the underlying mechanisms behind the algae's diverse characteristics. The results show that KA is a valuable resource for potential therapeutic applications, but a deeper exploration of its various metabolites and rigorous research are necessary for a thorough understanding of its capabilities. [ABSTRACT FROM AUTHOR] more...

Marine algae, a rich source of bioactive substances, have long been utilized in biomedical and veterinary sciences. This study breaks new ground by assessing the antiviral therapeutic potential of water extracts from four algal species – Colaconema formosanum, Caulerpa microphysa, Gelidium amansii and Sarcodia suae – against vesicular stomatitis virus (VSV) infection. The standout among these was Sarcodia suae water extract (SSWE), which not only significantly repressed VSV replication and enhanced cell survival without cytotoxic effects, but also demonstrated its antiviral activity through interference with viral attachment, entry, RNA replication, and egress, and reduced VSV-induced autophagy in Mv1Lu cells during the late stages of infection. The EC50 of SSWE was 0.422 ± 0.14 mg ml‒1. The cytotoxicity assay confirmed the high biocompatibility of SSWE. This study identifies SSWE as a promising natural antiviral agent and elucidates its mechanisms of action, highlighting the need for further research to optimize its use in controlling VSV-related diseases. Highlights: The bioactive water extract of Sarcodia suae was identified as a sustainable antiviral agent for the algal cultivation industry. The antiviral activity of S. suae against vesicular stomatitis virus (VSV) infection was confirmed. The mechanisms of action of the extract from Sarcodia suae on the autophagic pathway were demonstrated. [ABSTRACT FROM AUTHOR] more...

Red algae, abundant along the Moroccan coast, have fostered an agar-agar industry. However, industrial processing of red algae produces significant fibrous waste, posing environmental challenges. A new challenge is to find sustainable methods for repurposing this fibrous waste. Valorizing red-algae fibers in building materials promotes sustainable development and eco-construction. This study aims to valorize these red-algae residues as fiber reinforcements in compressed earth bricks (CEB). Various mass ratios of red-algae fibers (0.5%–3%) were incorporated into CEB. The addition of raw red-algae fibers to mixtures slightly increased the Atterberg limit values of the earth mixture. A slight adjustment in manufacturing water content was also observed with fiber addition. The incorporation of red-algae fibers did not improve the mechanical strengths of the CEB. Nevertheless, at a 1.5% addition ratio, CEB exhibited compressive and flexural strengths of 4.07 and 0.77 MPa respectively. To enhance mechanical properties, fibers were pre-saturated and subjected to alkaline and double coating treatments. Untreated and treated fibers were added to CEB at an optimal mass addition rate of 1.5%. Pre-saturated fibers showed a slight improvement of 5% in mechanical strength. However, alkali-treated and double-coated fibers offer a significant improvement of 20% in the mechanical strengths of CEB, demonstrating the efficacy of treatments. [ABSTRACT FROM AUTHOR] more...

A new species of Callophyllis from Peter the Great Bay, Sea of Japan, Russia, is recognized based on the morphological and molecular analyses of rbcL and nrLSU sequences. We name this new species C. eduardii sp. nov. Phylogenetic analysis suggests that C. eduardii is distinct from other Callophyllis species and sister to a diverse group that includes monocarpogonial species from the northeastern Pacific and species from the Russian Pacific coast. Callophyllis eduardii is characterized by diminutive thalli, narrow anastomosing branches with acute apices and smooth margins and cystocarps, without an ostiole, scattered over the blade and at the margins in the middle and upper part of the thallus. This is the ninth species of the genus found in Russian waters. [ABSTRACT FROM AUTHOR] more...

This article provides an overview of the diversity and distribution of macroalgae in the Androth Island of the Lakshadweep Archipelago. The study reveals that the island is home to a wide range of algae, with 62 genera and 114 species identified. The most prevalent species are Bryopsis plumosa and Halimeda simulans. The article emphasizes the significance of macroalgae in maintaining ecological balance and biodiversity in the region, while also highlighting the threats they face from climate change, overfishing, and pollution. The authors stress the need for conservation strategies and further research to protect these valuable marine resources. The author, Rekha Govindan, is an experienced academician with expertise in marine biology and has contributed to the scientific community through various publications in biotechnology and related fields. [Extracted from the article] more...

The marine red alga, Gracilaria eucheumatoides, is economically significant for its agar production and pharmacologically active compounds. This study reveals its complete mitochondrial genome (mitogenome), sequenced using Illumina's next-generation technology. The mitogenome is a 25,909 bp circular molecule with a G + C content of 27.21%, comprising 24 protein-coding genes, two ribosomal RNA genes, 24 transfer RNA genes, and one open reading frame (ORF) with an unidentified function. Both gene structure and composition are highly conserved within Gracilaria. The phylogenetic analyses fully support a close relationship of G. eucheumatoides with other Gracilaria species, as well as its sister relationship with G. urvillei. This mitogenome sequencing effort of G. eucheumatoides provides crucial data for future phylogenetic research on marine red algae. [ABSTRACT FROM AUTHOR] more...

Specimens attributed to the genus Lithophyllum were collected during multiple surveys conducted along the Brazilian coast. These specimens were studied using DNA sequences from three molecular markers (COI5P, psbA, rbcL) and comparative morphoanatomical analyses. This approach revealed eight distinct, well-supported lineages: two currently known species, Lithophyllum atlanticum and L. kaiseri; four new species, L. brasiliense sp. nov., L. pseudomargaritae sp. nov., L. solis sp. nov. and L. tomitae sp. nov.; and two additional lineages that remain unresolved as the available data were incongruent or insufficient. Lithophyllum pseudomargaritae was morpho-anatomically similar but distantly related to sequences from the type locality of specimens morphologically identified as L. margaritae. This study confirms the occurrence of cryptic/pseudocryptic coralline diversity in the Brazilian flora. [ABSTRACT FROM AUTHOR] more...

We investigated fresh collections and dry specimens (attached and loose-lying forms) of the endemic species previously named 'Coccotylus orientalis' from the Russian Pacific coast using morphology and sequencing of the plastid rbcL gene and mitochondrial COI-5P. 'Coccotylus orientalis' formed a clade, which was separated from other Coccotylus species, including the generitype Coccotylus brodiei, and also distinct from other genera in the Phyllophoraceae. It was sister to a clade containing Stenogramma spp. Morphologically 'C. orientalis' clearly differs from Stenogramma by the location of cystocarpic sori along the upper edge of the blades, versus along the median line of the blades in Stenogramma. We describe Neococcotylus orientalis gen. nov. et comb. nov. Neococcotylus differs from Coccotylus by elongated, convex cystocarps located on both sides of the blade parallel to the upper edge and cruciately divided tetrasporangia, formed in catenate rows within nemathecia, in contrast to Coccotylus that has carpotetrasporangia. Neococcotylus is monotypic and only known from Peter the Great Bay (Far East of Russia, Sea of Japan). [ABSTRACT FROM AUTHOR] more...

We evaluated the potential for co-cultured of red hybrid tilapia with Gracilaria changii in two different densities in zero water exchange conditions. Five treatments were performed, consisting of three monoculture systems as controls: algae at two different densities (M1 and M2 with 1 g L−1 density and 3 g L−1 density, respectively) and fish without algae (Mfish). For comparison purposes, the other two treatments were co-cultured fish with algae at densities of 1 g L−1 (P1) and 3 g L−1 (P2). The effects of different culture systems and densities on the water quality, growth performance, nutrient content and C/N ratio of the algae were determined. During the experimental period, the dissolved oxygen (DO) and pH values in the algal tanks (monoculture and co-culture) were significantly higher than those in the Mfish tank. The ammonia and nitrate concentrations in P1 and P2 were significantly lower compared to initial measurements. The water parameters indicated that the algae improved the water quality of the culture system. Compared to the fish monoculture (Mfish), the fish grew better with algae (P1 and P2) maybe due to the more favourable water conditions in the tanks. On day 20, the algae growth rates in the co-culture tanks (P1 and P2) were significantly higher than those in the monoculture tanks. Additionally, P1 and P2 improved the nutrient composition and C/N ratio of the algae. This study found that although the co-culture system resulted in better water quality and nutrient content in the alga, the algal density had no significant effect on fish or algal growth. [ABSTRACT FROM AUTHOR] more...

The genus Visia is reappraised based on new morphological and molecular data (rbcL and COI-5P sequences), from recently collected and previously studied materials, resulting in the need for several taxonomic changes. Based on our phylogeny and sequence divergence, the genus Visioidea gen. nov. is proposed for two samples from Brazil, forming a distinct clade that is morphologically undistinguishable from the generitype of Visia (V. cayennensis). Two lineages of Visia with high genetic divergences from other species are proposed as new species: 1) V. verviridis sp. nov. from Australia; 2) V. amazonensis sp. nov. from Brazil. Although genetically distinct, both species are morphologically very similar to V. cayennensis. A new record of V. cylindrocellularis was found in Australia, expanding the geographic distribution and the morphometric ranges for this species. The number of species currently recognized in Visia is now six, four with DNA sequence data and two identified based solely on morphology (V. longiarticulata and V. turgida). Cryptic genera within the order Batrachospermales were not recognised until recently with the proposals of Volatus, morphologically indistinct from Kumanoa, and Macrosporophycos undistinguishable from Montagnia and here a third cryptic genus Visioidea is described. [ABSTRACT FROM AUTHOR] more...

Nature derived compounds represent a valuable source of bioactive molecules with enormous potential. The sea is one of the richest environments, full of skilled organisms, where algae stand out due to their unique characteristics. Marine macroalgae adapt their phenotypic characteristics, such as chemical composition, depending on the environmental conditions where they live. The compounds produced by these organisms show tremendous potential to be used in the biomedical field, due to their antioxidant, anti-inflammatory, immunomodulatory, and anti-cancer properties. Cancer is one of the deadliest diseases in the world, and the lack of effective treatments highlights the urgent need for the development of new therapeutic strategies. This review provides an overview of the current advances regarding the anti-cancer activity of the three major groups of marine macroalgae, i.e., red algae (Rhodophyta), brown algae (Phaeophyceae), and green algae (Chlorophyta) on pancreatic, lung, breast, cervical, colorectal, liver, and gastric cancers as well as leukemia and melanoma. In addition, future perspectives, and limitations regarding this field of work are also discussed. [ABSTRACT FROM AUTHOR] more...

The crustose coralline alga Lithophyllum stictiforme is an important reef builder, forming coralligenous concretions in the Mediterranean Sea. This algal species complex is composed of eight cryptic species (or clades). The objective of our study was to compare light-dependent physiological processes within and between the two most abundant cryptic species (C1 and C4) of L. stictiforme from the Bay of Marseille (France). Physiological rates of respiration, photosynthesis and calcification were measured using incubation chambers under various irradiance levels and in the dark during the summer period. We compared the physiology of the C1 and C4 cryptic species of L. stictiforme among three algal groups: C1 (the most common in the Marseille area) from 28 m depth, C4 from the same site and depth, and C1 from a deeper site at 45 m depth. We found both interspecific (between C1 and C4) and intraspecific (within C1) physiological differences. Photosynthetic parameters showed acclimation to light (or depth) with higher values of initial slope of photosynthetic light response curve (α) and lower values of saturating irradiance (Ek) and compensating irradiance (Ec) for C1 from 45 m than for C1 and C4 from 28 m depth. At the shallower depth, significant physiological differences were observed between C1 and C4 with a higher value of maximum rate of gross photosynthesis (Pg max) in C4, suggesting better ability to grow under high irradiance. Light and dark calcification rates differed only between C4 from 28 m and C1 from 45 m depth, being intermediate in C1 from 28 m depth. On a 24 h basis, diel net calcification rates were significantly higher in specimens from the shallower waters than from the deeper waters. Physiological differences suggest physiological plasticity within the regionally dominant cryptic species C1 and species-specific physiological traits between the cryptic species C1 and C4. Photosynthesis and calcification rates differ among Lithophyllum stictiforme cryptic species. The regionally dominant cryptic species exhibits light-dependent physiological plasticity. Physiological differences occur between cryptic species found in similar environments. [ABSTRACT FROM AUTHOR] more...

Understanding our biodiversity is of the utmost importance to determine evolutionary histories of organisms, reliably detect new incursions and select species for commercial operations. Advances in molecular techniques have provided a strong tool to facilitate a deeper understanding of our biodiversity. Macroalgae are a polyphyletic group that comprises three phyla: Chlorophyta (green algae), Ochrophyta (brown algae) and Rhodophyta (red algae). These three algal groups have complex evolutionary histories, play essential roles in our ecosystem, and provide a diverse range of commercial products (e.g. food) and services (e.g. bioremediation). New Zealand is known for its high and unique biodiversity, including macroalgae. Here, we compared all named macroalgal species to publicly available DNA sequence data in the NCBI database (GenBank) with the aim to assess the number of sequenced species and determine which groups require more work. Our review revealed that the majority of named macroalgal species in New Zealand have been either not sequenced or have not been sequenced from New Zealand specimens. Furthermore, the majority of sequenced species have fewer than 10 sequences publicly available. This lack of DNA sequence data dramatically impacts our understanding of our biodiversity, the detection of new incursions, and hinders the utilisation of our unique diversity commercially to its highest potential. [ABSTRACT FROM AUTHOR] more...

Seven species of Callophyllis have been known off the Pacific coast of Russia; hovewer, molecular data have been obtained only for three species. In this study we re-examined the genus along the Russian Pacific coast using a comparative morphological study and molecular analyses based on rbcL and nrLSU. Five genetic species were identified on the Russian coast based on phylogenetics and species delimitation (ASAP and p-distance) analyses; while C. beringensis, C. papulosa and C. platyna were outscore of the analyses. The results of the molecular analyses uncovered one undescribed species, which we named C. selivanovae sp. nov. The divergence between this species and other species of the genus varied from 1.16% to 5.66%, while intraspecific divergence in the genus was in a range of 0.00%–0.22%. In phylogenetic trees C. selivanovae was recognized as sister to a diverse clade including C. thompsonii, C. beringensis, C. violacea, C. flabellulata and C. variegata from the Pacific coast of Canada. Callophyllis selivanovae from the southeastern coast of Kamchatka is morphologically close to C. beringensis, described from St. Paul Island (Bering Sea); the two species differ in features of branching, shape and size of the terminal branches. We propose a new name, C. perestenkoae sp. nov., for the algae previously listed in the Russian flora as 'C. flabellata'. Pacific specimens assigned to C. perestenkoae differ from C. flabellata from the type locality (Atlantic, France) in having irregular branching, thicker apical branches, and smaller cystocarps. We also filled in the gaps in the description of C. radula for which procarp and tetrasporangia are described herein for the first time. [ABSTRACT FROM AUTHOR] more...

The polyextremophilic red algal class Cyanidiophyceae inhabits a wide range of extreme habitats (e.g. acidic geothermal areas and dim-light caves), and shows various cell morphologies (e.g., subspherical and club-shape) and trophic strategies (e.g., photoautotrophy, heterotrophy and mixotrophy). Historically, inconsistent observations of morphology and physiology have hindered taxonomic advancements in Cyanidiophyceae despite indications of species diversity from molecular studies. Here we revisited this taxonomic conundrum and explored their cryptic speciation based on multi-locus and morpho-physiological evidence examined from expanded taxa sampling, including 20 cultures and one environmental sample. Our multi-locus phylogeny revealed two well-supported monophyletic lineages: the C-lineage that is generically rich (including Cavernulicola, Cyanidiococcus, Cyanidiofrigus, Cyanidioschyzon, Cyanidium, Gronococcus, and Sciadococcus) and the G-lineage that currently only contains the genus Galdieria. Species delimitation analyses revealed at least 21 species in Cyanidiophyceae. Although our morpho-physiological observations failed to differentiate closely related species apart within a genus, we propose Cyanidiofrigus pintoensis gen. et sp. nov. as this species is in a highly divergent lineage with much lower thermal tolerance than other recognized species. Overall, our study fills the taxonomic knowledge gaps and expands the number of known species in Cyanidiophyceae. [ABSTRACT FROM AUTHOR] more...

Two members of the marine diatom genus Falcula, which has been little known for a long time, were found from the surface of some Japanese seaweeds; one was assigned to F. cf. media and the other was described as a new species, F. rectangularis sp. nov. Aside from the arcuate valves and slit-like apical fields, typical of the genus, detailed morphological observations using light and scanning electron microscopy revealed resemblance between F. cf. media and F. rectangularis in areolae, stria density and lack of costae. However, the two species can be distinguished based on several morphological features, including the valve length, plastid arrangement, and frustules in girdle view. A three-gene molecular phylogeny recovered these two species as monophyletic with a high interspecific rbcL difference, which in turn were sister to the clade containing taxa that belong to the orders Cyclophorales and Protoraphidales with low support. The members in this poorly supported assemblage share apical fields composed of slits. The two species of Falcula were phylogenetically distinct from Pseudofalcula hyalina, a member previously assigned to Falcula. [ABSTRACT FROM AUTHOR] more...

Species identification in red algae poses significant challenges when relying solely on morphological characteristics. Consequently, the absence of molecular information often conceals misidentifications, cryptic diversity and introduced cryptic species. Within the genus Lophocladia, species have traditionally been delineated based on subtle morphological traits. Lophocladia trichoclados and Lophocladia lallemandii have been extensively documented in warm and temperate coastal regions, with the latter recognized as an invasive species in the Mediterranean. However, the molecular relationship between these species remains unexplored. To address this gap, a comprehensive taxonomic reevaluation of Lophocladia was conducted in the NE Atlantic, Mediterranean Sea and Red Sea. Through combined molecular and morphological analyses of 75 specimens, two distinct taxa of Lophocladia were identified within the study area. Sequences of the rbcL plastid gene unequivocally demonstrated that L. lallemandii and L. trichoclados are conspecific. Consequently, we propose the synonymization of L. lallemandii with L. trichoclados, which has nomenclatural priority. We report L. kuetzingii, a potentially introduced species from Australia, for the first time in the Macaronesian region of the North Atlantic. This finding underscores the importance of expanding red algal DNA datasets, as such efforts significantly enhance our ability to detect and discern introduced species. Additionally, this research highlights the existence of taxonomic uncertainties surrounding introduced species, even among those already classified as invasive. Molecular tools reveal the synonymy of Lophocladia lallemandii with L. trichoclados. L. trichoclados is a widely distributed species in the Atlantic, Mediterranean and Red Sea. L. kuetzingii is detected as a cryptic introduced species in the Macaronesian region. [ABSTRACT FROM AUTHOR] more...

Among marine primary producers, macroalgae support complex and productive coastal food webs, but coastal primary production relies on terrigenous inputs and remineralized organic matter which both vary seasonally. An approach combining stable isotope and biochemical analyses enables a better characterization of macroalgae specificities and highlights environmental influences on their chemical signature. This study compared the isotopic signature and biochemical composition of 22 Mediterranean macroalgae belonging to Rhodophyta (red algae), Phaeophyceae (brown algae) and Chlorophyta (green algae) between March and November 2010 to capture the differences in species chemical signatures potentially driven by metabolic traits or environmental drivers. Carbon stable isotope values were evidenced as a good proxy of specific carbon metabolism: low values observed in red algae could be related to the reported absence of carbon concentrating mechanisms (CCMs) in this group while higher values were driven by strong CCM activity in green algae. Biochemical patterns also differed between groups: soluble carbohydrates were a major component for red algae, while lipids and proteins dominated in brown algae, and insoluble carbohydrate concentrations were high in green algae. Variation within species across two collection times could be related to environmental changes and algal metabolism. δ15N values confirm the efficiency of this parameter as a proxy of the impact of human influence in the Bay of Marseille. Isotopic and biochemical content was measured in 22 Mediterranean macroalgae. Carbon descriptors are related to the metabolism of the specific macroalgal group. Seasonal variation of descriptors correlates with environmental variability. [ABSTRACT FROM AUTHOR] more...

Sea surface temperature is increasing, and we still do not have a good understanding of the effects of these temperature rises on haploid-diploid phases of many isomorphic red algae. In this study, we aimed to investigate the physiological performance of unfertilized and cystocarpic female gametophytes, fertile male gametophytes, and fertile tetrasporophytes of Gracilariopsis tenuifrons at different temperatures (20°C, 25°C and 30°C). We evaluated growth rates, maximum quantum yield by in vivo chlorophyll fluorescence, pigment content (phycoerythrin, PE; phycocyanin, PC; allophycocyanin, APC; chlorophyll a; and carotenoids), thallus length, and number of branches. At 30°C, tetrasporophytes showed greater growth, PE and number of branches, when compared to the others. However, intermediate temperature (25°C) resulted in higher growth, thallus length, PC and APC in unfertilized female gametophytes when compared to tetrasporophytes, and both phases showed better physiological performance than cystocarpic female gametophytes and male gametophytes. The latter two showed reduced physiological performance possibly owing to their sensitivity to temperature plus the imposition of fertility when compared to the unfertilized female gametophytes and fertile tetrasporophytes. In general, regardless of temperature, the presence of cystocarps negatively affected the physiological performance of female gametophytes. The occurrence of a complex life cycle, in which there is alternation of independent generations with distinct physiological responses, even if isomorphic as in G. tenuifrons, can bring advantages to the species in occupying thermally variable environments, enabling the increase and survival of one or another phase throughout the year. [ABSTRACT FROM AUTHOR] more...

This work is based on coralline red algal flora-dominated Lower Miocene carbonates of the Qom Formation from Central Iran Basin. Five assemblages, including corallinoid, lithophylloid, mastophoroid, melobesioid and sporolithoid corresponding to 11 genera of geniculate and non-geniculate, were identified. Also, growth forms and taphonomic characteristics of coralline-algal grains were assessed. The arborescent, layered to foliose lamellae, fruticose, lumpy, warty and encrusting growth forms of studied taxa are observed and five taphonomic traits belonging to both mechanical [abrasion, disarticulation, fragmentation] and biological [encrustation, bioerosion] processes were recognised. The relative abundance of assemblages, growth forms, and taphonomy of red algae visualised at thin-section scale were calculated. Our quantitative analysis highlights mechanical (abrasion > fragmentation) and biological (bioerosion> encrustation) processes. Moreover, layered to foliose and fruticose abundance peaks reveal higher than others. This kind of algal distribution in the examined region indicates that the Qom Formation was deposited on a marine carbonate shelf, which is a deepening depositional system in tropical and subtropical zone. This approach expresses more abundance of red algal assemblages on the deep part of inner and proximal to distal middle shelf settings along with a regime of moderately high towards low hydrodynamic energy and mesophotic – oligophotic conditions. [ABSTRACT FROM AUTHOR] more...

Nigrospora (Xylariales, Apiosporaceae) consists of species of terrestrial plant endophytes and pathogens. Nigrospora has also been reported in marine environments such as mangroves, sea fans, and macroalgae. However, limited research has been conducted on Nigrospora associated with macroalgae. Here, we isolated Nigrospora species from three types of algae (brown, green, and red algae) from Korean islands (Chuja, Jeju, and Ulleung) based on phylogenetic analyses of multigenetic markers: the internal transcribed spacers (ITS), beta-tubulin (BenA), and translation elongation factor 1 (TEF1-α). A total of 17 Nigrospora strains were isolated from macroalgae and identified as nine distinct species. The majority of Nigrospora species (seven) were found on brown algae, followed by red algae (three), and then green algae (two). To our understanding, this study represents the first account of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, N. osmanthi, N. pyriformis, and N. rubi occurring in marine environments. Additionally, this study provides the first report of the occurrence of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, and N. osmanthi in South Korea. This study will provide valuable insights for future research exploring the functions of fungi in macroalgal communities. [ABSTRACT FROM AUTHOR] more...

Phycoerythrin (PE) is a photosensitive red pigment from phycobiliprotein family predominantly present in the red algae. The concentration of PE depends on photon flux density (PFD) and the quality of light absorbed by the algae tissue. This necessitates robust techniques to extract PE from the embedded cell-wall matrix of the algal frond. Similarly, PE is sensitive to various factors which influence its stability and purity of PE. The PE is extracted from Red algae through different extraction techniques. This review explores an integrative approach of fractionating PE for the scaling-up process and commercialization. The mechanism for stabilizing PE pigment in food was critically evaluated for further retaining this pigment within the food system. The challenges and possibilities of employing efficient extraction for industrial adoption are meticulously estimated. The techniques involved in the sustainable way of extracting PE pigments improved at a laboratory scale in the past decade. Although, the complexity of industrial-scale biorefining was found to be a bottleneck. The extraction of PE using benign chemicals would be safe for food applications to promote health benefits. The precise selection of encapsulation technique with enhanced sensitivity and selectivity of the membrane would bring better stability of PE in the food matrix. [ABSTRACT FROM AUTHOR] more...

To address the taxonomic uncertainty of Sporolithon species named in the early to mid-20th century, targeted PCR sequencing was performed on eight historical type specimens and on recently collected specimens. Six type specimens amplified for the rbcL gene and were Sanger sequenced yielding sequences ranging in length from 118 to 280 base pairs (bp). One, S. australasicum, failed to amplify and another, S. howei, was amplified for the psbA gene yielding a sequence 544 bp in length. The 118 bp long rbcL sequence of the lectotype of S. crassiramosum showed that it is a later, heterotypic synonym of S. molle. The rbcL sequences of type specimens of S. episoredion, S. schmidtii, S. sibogae and S. timorense ranged from 118 to 228 bp, and each is a distinct species. The 544 bp long psbA sequence of S. howei is also unique. The 280 bp long rbcL sequence of the lectotype of S. durum did not match any sequence with that name in any public repository, including the previously published complete plastome and mitogenome sequences. However, it was identical in sequence to a specimen in GenBank from the southern coast of Western Australia as well as several other sequences generated from field-collected specimens from the states of South Australia and Western Australia. The rhodolith specimens from New Zealand previously called S. durum are S. nodosum sp. nov. The species is endemic to New Zealand. The epilithic specimens from New Zealand previously called S. durum are S. immotum sp. nov., which is also found along the southeastern coast of Australia. Sporolithon crypticum sp. nov. is described from the southern coast of Western Australia. RAxML and Bayesian phylogenetic analyses of Sporolithon psbA and rbcL sequences are congruent between the two plastid encoded genes. DNA sequencing of type specimens of species of corallines is demonstrated to be the only reliable method to correctly apply names. [ABSTRACT FROM AUTHOR] more...

DNA sequences obtained from the isolectotype of Jania crassa, collected from Dusky Sound, Fiordland, New Zealand, have revealed the identity of this poorly understood taxon, and enabled comparison with modern material. The name Jania crassa has been previously widely applied in New Zealand and Australia. Data presented here show that Jania crassa differs from other species within the New Zealand region: of the eight species of Jania currently recognized, three are dichotomously branched, and two of these are known from southern New Zealand. Jania crassa can be distinguished from the smaller and epiphytic species of Jania in southern New Zealand, J. sphaeroramosa, on the basis of size and growth habit. Jania crassa appears to be an infrequently collected, possibly endemic species of southern New Zealand, with only one recent collection confirmed. Further collections and sequence data are needed to better understand the distribution of this species, particularly in neighbouring regions. [ABSTRACT FROM AUTHOR] more...

The non-geniculate coralline algal genus Crustaphytum occurs in subtropical regions of the Pacific and Atlantic Oceans and presently contains only two species, C. pacificum and C. atlanticum. In contrast, the genus Mesophyllum is more widely reported and has representative species in both warm and cold waters. We analysed the species diversity of collections of Crustaphytum and Mesophyllum-like specimens from the Asian-Pacific region, based on psbA and rbcL sequence analyses and morphology. Our molecular analyses showed that the collections of Mesophyllum-like specimens mostly belonged to Crustaphytum with only a few specimens clustering with the Mesophyllum/Melyvonnea complex. We also describe three new species of Crustaphytum (C. taiwani-boreale sp. nov., C. taoyuanense sp. nov. and C. fragile sp. nov.) that are commonly found in the algal reefs in Northwest Taiwan, utilizing both scanning electron and light microscopy, and DNA sequence analyses. Crustaphytum fragile (79–95 μm thick) and Crustaphytum taiwani-boreale (235–436 μm thick) mostly grow in similar habitats in the algal reefs and can only be distinguished by a combination of characters relating to tetrasporangial chamber size and the number of cell layers in the cortex and medulla. Crustaphytum taoyuanense (233–300 μm thick) can be separated from the other species by its violet-red colour and by the margins of older thalli becoming overgrown by adjacent thalli. Crustaphytum taoyuanense and C. fragile are restricted to Taoyuan City in Northwestern Taiwan, whereas C. taiwani-boreale has a broader distribution in Northern Taiwan. Our study reveals a rich species diversity of Crustaphytum in the warm water region of the Western Pacific Ocean. [ABSTRACT FROM AUTHOR] more...

A descriptive model of calcification in the coralline red algae is integral to understanding their contributions to marine geochemistry, the responses of seascapes to global change, and their own evolution and ecology. Yet, the development of a holistic model of this process has so far been limited by the intrinsic challenge of assembling multiple lines of experimental and observational evidence from varied disciplines. To resolve this synthetic gap, we integrated ultrastructural, geochemical, biochemical and physiological data against a backdrop of anatomy and morphogenesis, which provide context for the localized process at play within the algal thallus. This synthesis represents a comprehensive description of calcification in the coralline red algae. [ABSTRACT FROM AUTHOR] more...

Geniculate coralline algae in temperate waters form dense, carpet-like turfs and are prevalent in intertidal rocky habitats or as understory beneath canopy-forming seaweeds in shallow subtidal zones. Using laboratory cultures, we determined the optimum and vital growth conditions for sporelings of two geniculate species, Amphiroa cf. zonata and Corallina berteroi, which are dominant in temperate waters around Japan. Samples were genetically identified as matching those two species as known from the coasts of Japan and worldwide, respectively. The optimum water temperature range and the upper critical water temperatures for sporeling growth were similar for the two coralline species. The optimum growth temperatures of A. cf. zonata (25–30°C) and C. berteroi (20–25°C) were comparable to those for temperate seaweeds commonly found in the same temperate region of Japan as the study sites. However, the upper critical temperatures for growth (33°C in A. cf. zonata and 32°C in C. berteroi) were higher than what is known for temperate kelps, though similar to those for other macroalgae. Amphiroa cf. zonata in the upper subtidal zone exhibited photoinhibition in conditions of less than 400 µmol photons m–2 s–1, whereas C. berteroi in the intertidal zone did not show such photoinhibition. The difference in irradiance effects upon growth was inferred to be related to the species distributions in their local environments of the coastal zone. [ABSTRACT FROM AUTHOR] more...

Phymatolithon is a dominant genus in the algal reefs in Northwest Taiwan. In this study, we describe three new species of Phymatolithon, P. fragile sp. nov., P. taiwanense sp. nov. and P. variabile sp. nov., based on morpho-anatomical characters examined with both light and electron microscopy, and DNA sequence analyses. Phymatolithon fragile is only found in northern Taiwan (a subtropical area) and can be separated from the other species from Taiwan based on its thin thallus (<130 µm thick when mature vs >200 µm in other species) and the possession of bisporangia only. Phymatolithon taiwanense and P. variabile are widely distributed in both northern (subtropical) and southern (tropical) Taiwan and can only be distinguished by a combination of characters relating to the sizes of tetrasporangial compartments and the number of cell layers in cortex and medulla. In addition, P. taiwanense and P. variabile are the first two species of Phymatolithon shown to occur in tropical waters. This study suggests that our knowledge of the species diversity of Phymatolithon in tropical regions, particularly in the Indo-Pacific, will increase when more collections are made and analysed by a combination of morphological and molecular approaches. [ABSTRACT FROM AUTHOR] more...

Seaweeds are macroscopic marine algae that are allocated into three categories based on the seaweed color (green, brown and red seaweeds). Seaweeds are known for its nutrition and beneficial non-nutritive compounds. Seaweeds have ample nutrition content including carbohydrates, minerals, proteins, and vitamins. Green seaweeds have a high concentration of carbohydrates and lipids whereas red seaweeds have abundant content of proteins. The mineral content ranges up to 36% of its dry weight. The beneficial non-nutritive compounds are phenolic compounds that are classified into phenolic acids, flavonoids, bromophenols and phlorotannins in seaweeds. The phlorotannin compounds are found mostly in brown seaweeds whereas the bromophenols are observed in red seaweeds. The phenolic compounds identified demonstrated bioactive properties which have been confirmed through in vivo cell culture studies. Due to seaweed's beneficial properties, the seaweed biomass have been consumed as a portion of convenience food in the Asian diet and has expanded to the Western diet. Over the last few decades, the extract or the biomass has been used in making fertilizers, animal feed, pharmaceuticals, and cosmeceuticals. This review helps to understand the nutrition content, especially phenolic compounds with their bioactive properties and recent development in applications. [ABSTRACT FROM AUTHOR] more...

Antarctic macroalgal communities of the upper intertidal zone are particularly poor compared with other coastal regions. Exposure to desiccation and freezing combined with the abrasive effect of ice threatens the life of sessile organisms. One of the few species able to colonize this environment is the rhodophyte Pyropia endiviifolia. It belongs to the Bangiales, one of the oldest extant clades of photosynthetic eukaryotes, which has occurred for more than one billion years with basically the same morphological structure. Considering that the extent of Antarctic glaciation is a geologically recent event, we hypothesized that pre-adaptations to desiccation in bangiophytes may have contributed to the success of P. endiviifolia in Antarctica. To test this, we compared its photosynthetic performance and tolerance to desiccation and freezing with those from a related intertidal species, the temperate Atlantic species Porphyra linearis. As evidenced by gas exchange and chlorophyll fluorescence, P. endiviifolia is more adapted to high irradiances than P. linearis. The former species was also more desiccation-tolerant, and showed a higher glass transition temperature. Both species did not differ in chlorophyll content per dry weight, and tolerance to −20°C, even though the ice-nucleation temperature was much higher in P. endiviifolia. Membrane integrity may depend on fatty acid composition in P. endiviifolia, while on enhanced tocopherol in P. linearis. Overall, both species show different strategies to deal with freezing temperatures: supercooling in P. linearis vs. freezing-tolerance in P. endiviifolia. This matches with the probability of being subjected to sub-zero temperatures in their natural environments (lower in the case of P. linearis). Surprisingly, the higher risk of dehydration in the natural habitat of P. linearis is not matched by a higher desiccation tolerance. This observation does not support the initial hypothesis of the study but suggests the opposite: the acclimation to a cold environment results in higher desiccation tolerance. HIGHLIGHTS ● Porphyra linearis and Pyropia endiviifolia are remarkably tolerant to desiccation and freezing.● Antarctic P. endiviifolia is remarkably tolerant to desiccation and freezing.● Mechanisms of freezing tolerance could induce a higher tolerance to desiccation. [ABSTRACT FROM AUTHOR] more...

Fatty acids and bulk geochemical proxies were employed to understand the sources and transformation of sedimentary organic matter from surface sediments of major five mangrove systems in the northern Kerala coast. Texture, tidal rhythm and the proximity to the south eastern Arabian Sea were the main factors influencing distribution and accumulation of the organic matter in these systems. A total of 118 fatty acids were quantified and grouped into short-chain (SCFA), long-chain (LCFA), monounsaturated (MUFA), polyunsaturated (PUFA) and branched-chain (BrFA) fatty acids, hydroxy fatty acids, cyclic fatty acids, and dicarboxylic acids. The distribution of fatty acid groups was in the order SCFA > BrFA > MUFA > LCFA > PUFA. Total fatty acids (TFA) concentration exhibited profound seasonal variations and ranged from 6.25 to 580.49 lg/g (pre-monsoon > post-monsoon > monsoon except in Kadalundi which follows the reverse order). The sedimentary fatty acids in the study region reveal a wide spectrum of inputs from terrestrial, planktonic (preponderance of diatom followed by dinoflagellates along with brown algae, cyanobacteria, red algae) and bacterial sources (e.g., Desulfobulbus-type bacteria, sulfur-reducing bacteria, Sulfur-oxidizing bacteria). Significant concentrations of bacterial fatty acids suggest the functioning of an effective microbial loop and various biogeochemical pathways operating in these sediments (sulfate reduction, iron and manganese oxide reduction, etc.). [ABSTRACT FROM AUTHOR] more...

For long-term management and conservation of marine resources an understanding of their genetic diversity and geographic distribution is necessary. The red alga Gracilaria salicornia is widely distributed along the coasts of Thailand and has been used as food and as fertilizer. However, there have been no studies examining the genetic diversity of this alga. The present research aimed to employ two different genetic markers, mitochondrial (COI-5P) and chloroplast (RuBisCO spacer) for exploring the genetic diversity and phylogeography of G. salicornia in Thailand. Our analyses, inferred from both markers, revealed different levels of genetic diversity between the two coasts of Thailand, and the recognition of seven new COI haplotypes. Gracilaria salicornia in the Andaman Sea had higher genetic diversity than in the Gulf of Thailand. Significant genetic divergence was found between populations in the Andaman Sea and the Gulf of Thailand, likely due to the geographic barrier of the Thai-Malay Peninsula and the complex ocean currents. No genetic structuring was detected in the Gulf of Thailand, whereas low to moderate genetic differentiation was found between populations in the Andaman Sea, suggesting a possible break between the northern and southern Andaman Sea. This break could be explained by ocean circulation patterns around the Malacca Strait. These findings provide further evidence supporting the Thai-Malay Peninsula and oceanographic currents as strong barriers to dispersal, leading to genetic differentiation and population structuring of G. salicornia and other marine species. These results can be used to guide conservation management actions and exploitation of this marine resource. [ABSTRACT FROM AUTHOR] more...

Grateloupia sensu lato has had a long and troublesome taxonomic history because of superficial similarities in morphology, ill-defined species boundaries and lack of diagnostic characters that leave many gaps that still need to be fully resolved. In this study, we carried out detailed observations on female reproductive structures, and inferred the phylogenetic relationships of the Grateloupia-like species occurring in Vietnam based on rbcL and LSU rDNA sequence analyses. The new species Phyllymenia nhatrangensis sp. nov. differs from its sister species P. gibbesii in the thickness of the cortex. The new species is slightly flattened, composed of two to four main blades, bearing numerous marginal and a few superficial, lanceolate bladelets. Blade sizes of P. nhatrangensis are also smaller than those of P. gibbesii, which are longer and wider. However, the new species shares with species from western Pacific Ocean, such as P. taiwanensis and P. huangiae, the presence of frequent marginal proliferations. Based on rbcL, the divergence between P. nhatrangensis and P. gibbesii was 3.3% (39 bp). With the present addition, Grateloupia sensu lato now comprises 16 species, including nine species of Grateloupia, three species of Phyllymenia, two species of Yonagunia and one species each of Dermocorynus and Prionitis. [ABSTRACT FROM AUTHOR] more...

Molecular sequence analyses of specimens previously identified as Cirrulicarpus sp. in the southeastern Brazil (Espírito Santo coast), indicated that they are more closely related to the genus Meredithia than to the genus Cirrulicarpus. The new species Meredithia dichotoma is herein proposed to accommodate this uncommon and endemic taxon, morphologically characterized by an erect, narrow, strap-shaped thallus, up to 16 cm long, mostly dichotomously branched, with regular constrictions, densely to moderately filamentous medulla, with occasional ganglionic cells, and an expanded medullary region in the basal transverse sections, resembling a midrib in surface view. The species is also supported by the sequence divergence from its congeners: ≥4.3% and 2.2% in the COI-5P and rbcL markers, respectively. Meredithia dichotoma differs from other 11 species of the genus by its dimensions and general habit, never forming expanded blades. This is a new genus record for Brazil and the first species of Meredithia known to occur in the western South Atlantic, increasing the known diversity in the red algal family Kallymeniaceae. [ABSTRACT FROM AUTHOR] more...

Genetic sequencing of herbarium specimens provides invaluable information on species genetic history. However, several factors hinder the extraction of high-quality DNA from long-term preserved specimens. Our goal was to study the genetic variability of the endemic and habitat-forming macroalga Gelidium canariense over the last 40 years using the mitochondrial intergenic marker cox2-3 spacer. We also studied the genetic diversity at the mesoscale (<100 km), i.e. between two localities on the north coast of Tenerife and at the macroscale (>100 km) using specimens collected on the island of La Palma. We found the presence of the same haplotype at the same location for the last 40 years. This haplotype also coincided within populations of Puerto de la Cruz and Garachico (Tenerife Island) and between populations of different islands (Tenerife and La Palma). This study provides a baseline (i.e. extraction method, PCR protocol for cox2-3 spacer molecular marker, level of DNA degradation of herbarium samples) of the genetic characterization of G. canariense that can be used in future molecular studies to better understand the distribution of genetic diversity in this vulnerable species. [ABSTRACT FROM AUTHOR] more...

Dudresnaya (Dumontiaceae, Gigartinales) and Acrosymphyton (Acrosymphytaceae, Acrosymphytales) are florideophycean genera (Rhodophyta) traditionally described as presenting a typical non-procarpic behaviour. The post-fertilization stages of their corresponding generitypes, D. verticillata and A. purpuriferum, have been described on many occasions. Nevertheless, some recent observations led the authors of this study to look more deeply into the development of the carpogonial and auxiliary fusion cells in the generitypes. Main results include a) description of the carpogonial fusion cell development by secondary connection (via fusion in D. verticillata and via conjunctor cells in A. purpuriferum); b) assessment of the existence, prior to diploidization, of primary auxiliary fusion cells in both species, and the description of their development and also that of the auxiliary fusion cells; and c) observation of occasional procarpic behaviour in both species, with gonimoblast developing from the secondary connecting filament initials in D. verticillata and from the carpogonial fusion complex in A. purpuriferum. The study has increased the understanding of the post-fertilization processes and supports the hypothesis that the procarpic behaviour is secondarily derived from non-procarpic ancestors. [ABSTRACT FROM AUTHOR] more...

Exotic species often slip through international borders undetected. Increased global trade has increased the frequency of species introductions. The marine aquarium trade is a significant vector of species introductions, including algal introductions. Molecular barcoding of tropical macroalgae entering the New Zealand aquarium trade was implemented using various molecular markers. Both NCBI BLAST searches and maximum-likelihood phylogenies were used to identify the isolates. A total of 62 species of tropical macroalgae were identified from coral rocks. Some species found are known as invasive elsewhere, for example, Caulerpa cylindracea, C. racemosa, C. sertularioides, Ulva ohnoi and Chaetomorpha vieillardii. All three major groups of algae were well represented with 26 species of red algae, 24 species of green algae and 12 species of brown algae. Temperature tolerance of some of these algae to minimum sea surface temperatures was tested. Results show that one species Chaetomorpha vieillardii can survive at Auckland minimum winter sea surface temperatures. Our findings have important implications for New Zealand biosecurity, as not only are a large diversity of exotic macroalgae entering the New Zealand marine aquarium trade unregulated, but there is also the potential for them to survive in New Zealand waters. [ABSTRACT FROM AUTHOR] more...

A new filamentous bangialean alga, Pseudobangia corderoi sp. nov., is described from the northern Philippines. Locally known as a sea vegetable, this species was previously identified as 'Bangia fuscopurpurea'. Inferred combined analyses of the nucleus-encoded SSU rDNA and the plastid-encoded RubisCO LSU (rbcL) gene indicate that P. corderoi is sister to another unidentified species of Pseudobangia (originally referred to also as 'Bangia fuscopurpurea') from Taiwan. Together, these two taxa formed the closest diverging lineage from Pseudobangia kaycoleae (generitype). Current molecular phylogenies have also yielded monophyly of Pseudobangia and strong support for a sister relationship with the 'Bangia 2' lineage. Molecular and geographic analyses clearly differentiate P. corderoi from other filamentous Bangiales, whereas morpho-anatomical analysis identified only one distinguishing character, i.e. larger dimensions of the thalli. [ABSTRACT FROM AUTHOR] more...

To determine whether Corallina chilensis is a distinct species or a variety (i.e. C. officinalis var. chilensis) of the generitype of Corallina, molecular phylogenetic analyses were performed using psbA, COI-5P, rbcL, or some combination of these gene regions from 75 voucher specimens representing Corallina collections from around the world. Names were applied by comparing these DNA sequences with sequences obtained from type specimens, including a 263 bp rbcL sequence from an isotype of C. chilensis collected by Darwin (C. Darwin 2151) from Valparaiso, Chile. DNA sequences from the C. chilensis isotype matched unnamed coralline DNA sequences from British Columbia, Canada, and previously published DNA sequences from the northeast and southeast Pacific. The clade containing the isotype of C. chilensis was distinct from C. officinalis specimens in phylogenetic analyses. Although morphologically variable, fronds of C. chilensis from British Columbia populations matched Kützing's original description of C. officinalis var. chilensis. These data support the conclusion that C. chilensis is a distinct species, not a variety of C. officinalis, and is distributed in both hemispheres. While this study strongly supported C. chilensis as a distinct species, phylogenetic relationships among Corallina species remain elusive because individual gene trees are not congruent. [ABSTRACT FROM AUTHOR] more...

A new genus of freshwater red algae, Macrosporophycos, and a new species, M. sahyadricus, are described from the Periyar River in the southern part of the Western Ghats, Kerala, India. Macrosporophycos shares distinctive characteristics with Montagnia, such as straight carpogonial branches having involucral filaments forming a rosette around the carpogonia, and pedunculate carposporophytes. However, the two genera have a raw genetic distance of 16.4%–17.0% for rbcL, and 24%–26.7% for COI-5P genes. The new species, Macrosporophycos sahyadricus, also possesses large, elongated, pear-shaped carposporangia. Phylogenetic analyses based on the concatenated rbcL and COI-5P recovered M. sahyadricus as a distinct lineage, sister to Acarposporophycos from South America. However, these genera are distinct from each other in their morphology. The morphological similarity, coupled with the high levels of genetic difference between Macrosporophycos and Montagnia, suggest convergent evolution in morphology. The recent records of new red algal taxa, including the discovery of this new genus, suggest that the Indian subcontinent continues to be under-explored and is in need of integrative taxonomic research supported by large-scale sampling. [ABSTRACT FROM AUTHOR] more...

The morphologically diverse and widespread red algal genus Plocamium has recently emerged as a source of bioactive compounds with potential application in the pharmaceutical industry. However, species identification and the taxonomy of the group remains problematic. An initial contribution to the taxonomy of Plocamium in South Africa was therefore carried out using combined morphological and molecular approaches and existing literature. Plocamium robertiae is reinstated as a distinct species based on molecular and morphological evidence, while Plocamium raphelisianum, a species from Spain, is placed in synonymy with P. suhrii. Along the South African coast, individuals of P. suhrii were genetically divergent in different bioregions and will require further investigation. Contrary to previous reports, we confirm the absence in South Africa of two Australasian species, P. microcladioides and P. mertensii, which were previosuly misidentified. The latter species likely represents a new, undescribed species in South Africa. Two additional species were also identified based on DNA but require further morphological assessment. We now recognize P. robertiae, along with eight other named species, plus five additional taxa, with varying levels of taxonomic confidence, and exclude P. microcladioides and P. mertensii from the South African flora. This study doubles the number of species recognized since the last biodiversity assessment of Plocamium and expands the distributional range of P. suhrii. Although our findings contribute an initial assessment assisted by DNA data, a full understanding of the taxonomy of Plocamium in South Africa is far from complete. [ABSTRACT FROM AUTHOR] more...

Kappaphycus malesianus is a red seaweed farmed primarily for its carrageenan, a polysaccharide important in the food and pharmaceutical industries. Among the commercially cultivated Kappaphycus species, only K. malesianus has no mitogenome data available. Here, we assembled the mitochondrial genome of K. malesianus from next-generation sequencing data. The circular mitogenome consisted of 25,250 base pairs (bp) with a GC content of 30.25%. These values were comparable to previously sequenced solieriacean mitogenomes. Structural features, such as the stem-loop and hairpin, which were previously reported in other rhodophytes mitochondrial DNA, were also identified. The annotated genes (24 protein-coding genes, 24 tRNA genes, and 2 rRNA genes) were arranged in an order similar to the other available solieriacean mitogenomes. Lastly, phylogenetic analysis using 23 predicted protein domains showed the sister relationship of K. malesianus with other Kappaphycus species. [ABSTRACT FROM AUTHOR] more...

In this study, R-phycoerythrin (R-PE) was isolated and characterized from Porphyra yezoensis by three-phase partitioning (TPP) method. The effects of temperature, time, pH, salt saturation, and volume ratio on the purity and recovery rate of R-PE were studied. The optimum extraction conditions were determined as follows: salt saturation of 70%, temperature of 25 °C, time of 45 min, pH of 7.0, and volume ratio of 1:1. Under the optimal extraction conditions, the purity of R-PE was 3.90. The results of SDS-PAGE showed that R-PE has three bands at 23 kDa, 22 kDa, and 18 kDa, corresponding to its α, β, γ subunits. The structure and optical activity of R-PE did not change before and after purification based on ultraviolet, infrared, and fluorescence spectra. In addition, the purity and recovery rate of R-PE extracted by tert-butanol were evaluated. The results showed that the extraction performance of tert-butanol for R-PE remained unchanged in three recoveries. These show that TPP is an efficient, green, and recyclable extraction technology. [ABSTRACT FROM AUTHOR] more...

Intertidal macroalgae are exposed to many biotic and abiotic stressors, including significant fluctuations in environmental parameters such as salinity, temperature, pH and solar radiation. This study characterized populations of the intertidal calcifying red alga Corallina officinalis across its geographic distribution in the North-east Atlantic. Processes examined included primary production, respiration, light and dark calcification, photosynthesis-irradiance, and calcification-irradiance evolution. Results confirmed significant differences in the physiology of C. officinalis between latitudes with a clear north-to-south gradient. Compared with central and southern populations of this species, northern populations appeared to be the most robust, showing potential for local physiological adaptation in response to increased variability in environmental factors present within their habitat. Conversely, southern populations displayed a distinct lack of local adaptation compared with northern populations. This is possibly due to southern populations being located within an environment at the upper limit of their stress tolerance, therefore restricting the species' ability to adapt. As a result, future permanent decline, or even disappearance, of C. officinalis within southern locations of the North-east Atlantic could occur, a process that is likely to be accelerated by predicted future climatic changes. Furthermore, given the essential role these ecosystem engineers play within their habitat, any loss of C. officinalis is also expected to have a strongly negative impact on the surrounding environment. HIGHLIGHTS Decoupled photosynthesis and calcification in Corallina. officinalis show complex relationships, not direct dependencies. Most physiological characteristics in northern C. officinalis populations differ significantly from those in central and southern locations. Species adaptation is predominantly to lower light and temperature conditions. [ABSTRACT FROM AUTHOR] more...

Algal susceptivity to inorganic arsenate As(V) is linked to the plant nutrient phosphate due to their similar uptake processes. This study determines the response of Sarcodia suae to three phosphate concentrations (1, 10 and 20 mg l–1) when exposed to As(V) (0, 250 µg l–1) for 7 days. The parameters measured include growth, pigments (Chlorophyll a (Chl a), allophycocyanin (APC), phycocyanin (PC), phycoerythrin (PE), total phycobiliproteins (TPBP) and carotenoids), inorganic arsenic (iAs), and total arsenic (TAs) uptake behaviour and bioaccumulation capacity. The growth rate showed significant differences among treatments. Significantly higher levels of pigments including Chl a and carotenoids were observed with an increase in external phosphate concentrations. On the other hand, APC, PC, PE and TPBP showed no significant differences among treatments. The trend of iAs and TAs uptake when phosphate is high suggests competition between phosphate and As(V) as is evident from the reduction of uptake with increased phosphate. The depletion of phosphate and As(V) in the medium also suggests accumulation by the algae. In addition, S. suae was considered an As accumulator but not a hyperaccumulator as defined on its bioaccumulation capacity of 48 and 97 mg kg–1 of iAs and TAs, respectively. Overall, these findings suggest that environmental factors including levels of phosphate have a key role in developing effective As bioremediation in the environment. Highlights Phosphate in Sarcodia suae probably regulates arsenic uptake. Photosynthetic pigments can be linked to competitive mechanisms of As(V). The red alga Sarcodia suae is a candidate for As wastewater treatments by Bioconcentration Factor analysis. [ABSTRACT FROM AUTHOR] more...

In the present paper, three algal species are recorded for the first time from Morocco: the two red algae Antithamnion villosum and Antithamnionella ternifolia and the green alga Lychaete rhodolithicola. Furthermore, two other red algae species are recorded for the first time from the Moroccan Atlantic coast and this part of the eastern Atlantic Ocean: Antithamnion amphigeneum and Antithamnionella boergesenii. Descriptions of these newly reported species are provided accompanied by photographs for each species. In addition, new observations and taxonomic remarks for some species are also provided. The green alga Lychaete rhodolithicola has a limited distribution in the North-eastern Atlantic Ocean of Europe, and the report of this species from Morocco extends the distribution of this species, because it is the first record of this species in Africa and outside Europe. This is one of the rare documentations with description and illustrations of L. rhodolithicola. The foliose species Grateloupia turuturu is studied in detail; it has been widely misidentified as G. doryphora. An examination of all specimens going under the name G. doryphora in the Moroccan herbaria has determined these specimens to be Grateloupia turuturu. An identification key for all Moroccan species of Antithamnion, Antithamnionella and Lychaete is presented. [ABSTRACT FROM AUTHOR] more...

The Lomentariaceae, previously treated as subfamily Lomentarioideae in the family Champiaceae, is one of the six families currently classified in the Rhodymeniales. Relationships within the family are not wellestablished, and new genera have been segregated from Lomentaria, a notoriously polyphyletic taxon as currently circumscribed. The lack of access to molecular data of type specimens has limited the taxonomic clarifications within the Lomentariaceae. Using new collections from Brazil, historical collections and data available in GenBank, we generated rbcL and COI-5P phylogenies of the Lomentariaceae, and we used species delimitation methods to assess the species-level diversity among sequences. A nuclear LSU rDNA phylogeny, although less representative in number of taxa, confirmed our findings. Our results recovered Ceratodictyon and Semnocarpa as monophyletic, whereas Lomentaria was polyphyletic. Integrating phylogenetic analyses, analyses of genetic variance, and morphological analyses, we revealed a new species, Ceratodictyon sanctae-crucis sp. nov., collected on the coast of Bahia (northeastern Brazil). Having included a newly generated sequence of the holotype of Lomentaria sinensis, a heterotypic synonym of L. hakodatensis, and a sequence from a sample collected near the type locality of L. hakodatensis, we propose the new genus Yendoa gen. nov. to accommodate this species. Our results support a more phylogenetically coherent taxonomic scheme for the Lomentariaceae, which now includes only monophyletic genera. [ABSTRACT FROM AUTHOR] more...

Phylogenetic analyses resolved that specimens from Manawatāwhi/Three Kings Islands in northern New Zealand, formerly identified as Sonderophycus coriaceus, belong to the genus Agissea (Peyssonneliales). This species is dark red, prostrate and robust, with leathery, fan-shaped lobes and is described here as Agissea teruruhau. It was found to serve as a host to a very small red algal epiphyte described here as Piriora waewaiti gen. & sp. nov. While phylogenetic analyses have placed Piriora in the Gigartinales, the familial placement of this genus has been unable to be resolved. Manawatāwhi/Three Kings Islands is a group of small islands known to harbour a rich marine biota with many endemic species, and the description of these taxa has increased the reported endemic algal flora of the islands. In addition, the phylogenetic analyses have confirmed the presence of Olokunia boudouresquei and a further three species of Peyssonneliales in the New Zealand flora, belonging to the genera Olokunia, Peyssonnelia and Seiria. [ABSTRACT FROM AUTHOR] more...

Non-geniculate coralline algal specimens were collected in 2013 during the XXVIII Italian Expedition to Antarctica in Adélie Cove (Terra Nova Bay; Ross Sea) and deposited in the collections of the Italian National Antarctic Museum (MNAIT, Section of Genoa). Specimens were characterized through a polyphasic approach combining DNA sequence data obtained for four genes (psbA, rbcL, 18S rDNA and cox1) with morpho-anatomical observations. DNA sequences revealed that all specimens belonged to the same species. Phylogenetic reconstructions unambiguously recovered this alga as a member of the order Hapalidiales, but without any close relationship to a genus of this order currently recognized on a molecular phylogenetic basis. Instead, it formed a well-supported lineage with specimens named 'Hapalidiales sp. ZH-Twist-2019', collected in New Zealand, for which no formal assignment at genus level has been proposed. Species delimitation methods (ABGD, PTP, GMYC) applied to the psbA dataset indicated that the Adélie Cove coralline alga is a distinct species from all other known hapalidialean species for which such sequences are available. A new genus, Thalassolithon gen. nov., is proposed for T. adeliense sp. nov. [ABSTRACT FROM AUTHOR] more...