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New Zealand's algal flora is still far from fully explored, and new taxa continue to be discovered. The taxonomy of the red algal order Hildenbrandiales, consisting mostly of crustose members, is controversial as descriptions are largely based on limited morphological features. The order Hildenbrandiales is also in a close, apparently obligate, relationship with an endophytic fungus. Apophlaea is a genus in this order currently comprising two described species, both endemic to New Zealand. The morphology of this genus is more complex than that of other members of the Hildenbrandiales as it consists of extensive upright thalli. Sampling of Apophlaea in New Zealand, especially in the southern part of the North Island, has led to the discovery of a genetically distinct entity, that is only crustose. We propose a new species for this entity, Apophlaea darchinoae sp. nov., which is found on rocks in the high intertidal zone. This species has the typical tetrasporangial conceptacles of Apophlaea and no other reproductive structures were observed, and it consists of filaments that are laterally joined by secondary pit connections. Apophlaea darchinoae can be found in sympatry with A. sinclairii in the north of the North Island. We provide molecular evidence for the distinct nature of A. darchinoae and provide observations of extensive fungal filaments within this new species. [ABSTRACT FROM AUTHOR]

A floristic survey of the marine algal biodiversity of Antsiranana Bay, northern Madagascar, was conducted during November 2018. This represents the first inventory encompassing the three major macroalgal classes (Phaeophyceae, Florideophyceae and Ulvophyceae) for the little-known Malagasy marine flora. Combining morphological and DNA-based approaches, we report from our collection a total of 110 species from northern Madagascar, including 30 species of Phaeophyceae, 50 Florideophyceae and 30 Ulvophyceae. Barcoding of the chloroplast-encoded rbcL gene was used for the three algal classes, in addition to tufA for the Ulvophyceae. This study significantly increases our knowledge of the Malagasy marine biodiversity while augmenting the rbcL and tufA algal reference libraries for DNA barcoding. These efforts resulted in a total of 72 new species records for Madagascar. Combining our own data with the literature, we also provide an updated catalogue of 442 taxa of marine benthic macroalgae from Madagascar, comprising 85 Phaeophyceae, 1 Compsopogonophyceae, 240 Florideophyceae and 116 Ulvophyceae. This diversity holds 29 (ca. 6.5%) endemic species to Madagascar. Our results are discussed in the context of increasing threats to biodiversity on Madagascar's coastal reefs from both anthropic and anthropogenic activities including sewage effluent runoffs and unsustainable agricultural practices such as massive deforestation, leading to ecosystem shifts to algal dominance on reefs, which are recommended to be addressed through integrated land-sea management in a Reef-to-Ridge conservation approach. [ABSTRACT FROM AUTHOR]

Early detection of non-indigenous species is crucial to reduce, mitigate, and manage their impacts on the ecosystems into which they were introduced. However, assessment frameworks for identifying introduced species on the Pacific Coast of South America are scarce and even non-existent for certain countries. In order to identify species’ boundaries and to determine the presence of non-native species, through morphological examinations and the analysis of the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL-5P) gene, we investigated the phylogenetic relationships among species of the class Florideophyceae from the coast of Ancash, Peru. The rbcL-5P dataset revealed 10 Florideophyceae species distributed in the following four orders: Gigartinales, Ceramiales, Halymeniales, and Corallinales, among which the Asian species, Melanothamnus japonicus (Harvey) Díaz-Tapia & Maggs was identified. M. japonicus showed a pairwise divergence of 0% with sequences of M. japonicus from South Korea, the USA, and Italy, the latter two being countries where M. japonicus has been reported as introduced species. Our data indicate a recent introduction event of M. japonicus in Peru, and consequently, the extension of its distribution into South America. These findings could help to adopt management strategies for reducing the spread and impact of M. japonicus on the Pacific Coast of South America.

Tunisia is located at a key position in the Mediterranean Sea where it constitutes a transitional area between the eastern and western basins benefitting from rich habitat diversity. The most recent inventory of marine macrophytes dated back to 1987 with an update in 1995, however these inventories were performed with identification based on morphological observations, which can be misleading for many seaweed species. To the best of our knowledge, this is the first study of the Tunisian macroalgal flora using DNA barcoding methods. Our target was to carry out a survey of macroalgae, to reveal cryptic species and allochthonous introductions, and to identify taxa with problematic taxonomy. COI-5P sequence analysis resolved 26 genetic species, including two new reports and three alien species. Of the remaining taxa, several displayed cryptic diversity relative to species reported from the Mediterranean versus from other geographical regions with taxonomic and nomenclature updates provided where possible. The aim of the present paper was to provide a DNA barcode-assisted floristic list of florideophycean algae collected along the Tunisian coast. [ABSTRACT FROM AUTHOR]

Background: The red algae (Rhodophyta) diverged from the green algae and plants (Viridiplantae) over one billion years ago within the kingdom Archaeplastida. These photosynthetic lineages provide an ideal model to study plastid genome reduction in deep time. To this end, we assembled a large dataset of the plastid genomes that were available, including 48 from the red algae (17 complete and three partial genomes produced for this analysis) to elucidate the evolutionary history of these organelles. Results: We found extreme conservation of plastid genome architecture in the major lineages of the multicellular Florideophyceae red algae. Only three minor structural types were detected in this group, which are explained by recombination events of the duplicated rDNA operons. A similar high level of structural conservation (although with different gene content) was found in seed plants. Three major plastid genome architectures were identified in representatives of 46 orders of angiosperms and three orders of gymnosperms. Conclusions: Our results provide a comprehensive account of plastid gene loss and rearrangement events involving genome architecture within Archaeplastida and lead to one over-arching conclusion: from an ancestral pool of highly rearranged plastid genomes in red and green algae, the aquatic (Florideophyceae) and terrestrial (seed plants) multicellular lineages display high conservation in plastid genome architecture. This phenomenon correlates with, and could be explained by, the independent and widely divergent (separated by >400 million years) origins of complex sexual cycles and reproductive structures that led to the rapid diversification of these lineages. [ABSTRACT FROM AUTHOR]

Two red algal classes, the Florideophyceae (approximately 7,100 spp.) and Bangiophyceae (approximately 193 spp.), comprise 98% of red algal diversity in marine and freshwater habitats. These two classes form well-supported monophyletic groups in most phylogenetic analyses. Nonetheless, the interordinal relationships remain largely unresolved, in particular in the largest subclass Rhodymeniophycidae that includes70%of all species. Toelucidate redalgalphylogenetic relationships andstudyorganelleevolution, we determined the sequence of 11 mitochondrial genomes (mtDNA) from 5 florideophycean subclasses. These mtDNAs were combinedwith existing data, resulting in a database of 25 florideophytes and 12 bangiophytes (including cyanidiophycean species). A concatenated alignment of mt proteins was used to resolve ordinal relationships in the Rhodymeniophycidae. Red algal mtDNA genome comparisons showed 47 instances of gene rearrangement including 12 that distinguish Bangiophyceae from Hildenbrandiophycidae, and 5 that distinguish Hildenbrandiophycidae from Nemaliophycidae. These organelle data support a rapid radiation and surprisingly high conservation of mtDNA gene syntheny among the morphologically divergent multicellular lineages of Rhodymeniophycidae. In contrast, we find extensive mitochondrial gene rearrangements when comparing Bangiophyceae and Florideophyceae and multiple examples of gene loss among the different red algal lineages. [ABSTRACT FROM AUTHOR]

We described the complete mitochondrial genome of Gracilaria chilensis (Gracilariales), an economically important agarophyte alga. The genome was a 26,898 bp circular DNA with 27.6% guanine-cytosine (GC) content, and it encoded 25 protein-coding genes, two ribosomal RNAs (rRNAs), 26 transfer RNAs (tRNAs), and an intron (499 bp) in trnI. The gene composition was similar to that of the published mitogenome of G. salicornia; however, one inverted and several direct repeat sequences occurred between secY and orf148 genes, resulting in duplicated trnR and trnS tRNA sequences. The mitochondrial genome also contained three integrated partial plasmid sequences, which were reported for G. robusta (Gro4059). [ABSTRACT FROM AUTHOR]

Parasitism is a common life strategy throughout the eukaryotic tree of life. Many devastating human pathogens, including the causative agents of malaria and toxoplasmosis, have evolved from a photosynthetic ancestor. However, how an organism transitions from a photosynthetic to a parasitic life history strategy remains mostly unknown. This is largely because few systems present the opportunity to make meaningful comparisons between a parasite and a close free-living relative. Parasites have independently evolved dozens of times throughout the Florideophyceae (Rhodophyta), and often infect close relatives. The accepted evolutionary paradigm proposes that red algal parasites arise by first infecting a close relative and over time diversify and infect more distantly related species. This provides a natural evolutionary gradient of relationships between hosts and parasites that share a photosynthetic common ancestor. Elegant microscopic work in the late 20th century provided detailed insight into the infection cycle of red algal parasites and the cellular interactions between parasites and their hosts. Those studies led to the use of molecular work to further investigate the origins of the parasite organelles and reveal the evolutionary relationships between hosts and their parasites. Here we synthesize the research detailing the infection methods and cellular interactions between red algal parasites and their hosts. We offer an alternative hypothesis to the current dogma of red algal parasite evolution and propose that red algae can adopt a parasitic life strategy through multiple evolutionary pathways, including direct infection of distant relatives. Furthermore, we highlight potential directions for future research to further evaluate parasite evolution in red algae. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive summary of the PCR primers and profiles currently in use in our laboratory for red algal DNA barcoding and phylogenetic research. While work focuses on florideophyte taxa, many of the markers have been applied successfully to the Bangiales, as well as other lineages previously assigned to the Bangiophyceae sensu lato. All of the primers currently in use with their respective amplification profiles and strategies are provided, which can include full fragment, overlapping fragments and what might best be called "informed overlapping fragments", i.e., a fragment for a marker is amplified and sequenced for a taxon and those sequence data are then used to identify the best primers to amplify the remaining fragment(s) for that marker. We extend this strategy for the more variable markers with sequence from the external PCR primers used to "inform" the selection of internal sequencing primers. This summary will hopefully serve as a useful resource to systematists in the red algal community. [ABSTRACT FROM AUTHOR]

The COI-5P DNA barcode (the 5′ region of the mitochondrial cytochrome c oxidase I gene) has proven an effective tool for quickly screening large numbers of biological specimens and assigning them to genetic species groups for subsequent examination in an approach known as molecular-assisted alpha taxonomy (MAAT). In the present study, we applied MAAT to Canadian species of the red algal genusCallophyllisin order to resolve confusion surrounding this taxonomically perplexing group. A total of 563Callophyllisspecimens were examined (either molecularly, morphologically or both) – 504 from British Columbia along the Pacific coast of Canada and 59 from the U.S.A., Australia and Chile. In total, 16 genetic species groups were resolved including 12 in Canada although only nine species are reported in the flora. Here we report range extensions ofC. beringensisandC. radulafrom the NW Pacific,C. dissectafrom California, U.S.A. and the Chilean speciesC. variegata(the type species) into the Canadian flora. Our results also uncovered cryptic diversity in the genus necessitating the description ofC. schneideriClarkston & G.W. Saunderssp. nov. Subsequent analyses of a subset of specimens using the internal transcribed spacer of the ribosomal cistron (ITS) resolved the same groups as COI-5P while the universal plastid amplicon (UPA, domain V of theplastid 23S rRNA gene) had poor resolution at the species level and in one case underestimated species diversity. Finally, large-subunit ribosomal DNA (LSU), nuclear elongation factor 2 (EF2), COI-5P and a combined LSU, EF2 and COI-5P alignment were subjected to phylogenetic analyses in order to investigate relationships among Canadian species ofCallophyllis. A significant outcome was the resolution of two well-supported lineages for the monocarpogonial versus polycarpogonial species of this genus, as had been posited in the literature. [ABSTRACT FROM PUBLISHER]

Two DNA extraction protocols and nine variations of advocated DNA barcode markers (nuclear LSU D2/D3, ITS1, ITS2, mitochondrial COI-5P, plastid rbcL, UPA) were assessed for their abilities to yield species-level resolution from archival collections of red algae. With the exception of LSU D2/D3, all markers trialed displayed the potential to resolve red algal species. However, shortened COI-5P (COIms) and ITS (ITS2r) markers displayed four to five times the intrageneric divergence of shortened plastid markers and are preferred for their resolving power. For recent archival samples (4-11 years), COIms, ITS2r, and UPA displayed >90% amplification success. However, success rates declined rapidly as samples ranging in age from ca. 45-180 years old were tested. Further, contamination was a serious concern in reamplifications (partially nested PCR), especially for markers using universal primers (e.g., UPA) and for trials that employed the best extraction procedure, i.e., the better an extraction protocol is at isolating small DNA fragments from archival material, the better it is at acquiring small contaminating fragments from the laboratory - an intuitive and unfortunate reality. The ramifications of our results for ongoing attempts to extract DNA from archival red algal collections using PCR-based protocols is discussed along with recommendations to improve the likelihood of authentic outcomes. [ABSTRACT FROM AUTHOR]

The red algal family Kallymeniaceae was surveyed along the west coast of Canada using the DNA barcode (COI-5P- 5' region of the mitochondrial cytochrome c oxidase I gene) as a species identification tool. A total of 253 specimens field identified as Pugetia spp. subsequently resolved as five genetic species groups, although only two are reported in the flora. Additionally, COI-5P data were available for the Chilean P. chilensis, which resolved as a distinct species. Subsequent analysis of the internal transcribed spacer of the ribosomal cistron and the universal plastid amplicon (domain V of the 23S rRNA gene) resolved the same groups as COI-5P. Phylogenetic relationships of the Canadian groups were investigated using large-subunit ribosomal DNA (LSU) and a combined analysis of LSU and COI-5P data. One species was divergent from the Pugetia spp. in all analyses and grouped closely with the kallymeniacean genera Erythrop/iylluin (Kallymeniaceae, Gigartinales) and Kallymeniopsis (Kallymeniaceae, Gigartinales) - it is here described as Beringia wynnei sp. nov. The other 'Pugetia' species fell into two divergent clusters in phylogenetic analyses, differing also in blade thickness, carpogonial branch morphology and the association of the auxiliary cell relative to the carpogonium (procarpic vs nonprocarpic). We retain the genus Pugetia for the type species P. fragilissima and P. cryplica sp. nov. and describe the new genus Salishia for Salishiajirnia (Kylin) comb. nov., S. sanguinea (Montagne) comb. nov. and S. chilensis (J. Agardh) comb. nov. Finally, we completed morphological and anatomical examinations of other Pugetia species to provide a comprehensive review of the genus. [ABSTRACT FROM AUTHOR]

Previous studies have established that the 5′ end of the mitochondrial gene COI (cytochrome oxidase subunit I) is useful for rapid and reliable identification of red algal species and have demonstrated that our understanding of red algal biodiversity and biogeography is fragmentary. In this context, we are completing a thorough sampling along the Canadian coast and using the DNA barcode for the assignment of collections to genetic species to explore algal diversity in the Canadian flora. In the present study, we provide results regarding diversity of members of the red algal family Phyllophoraceae. We have analyzed 354 individuals from the Arctic, Atlantic, and Pacific coasts of Canada, as well as 26 specimens from the USA, Europe, and Australia, resolving 29 species based on the analyses of the DNA barcode. Twenty-three of these genetic species were present in Canada where only 18 species are currently recognized, including Ceratocolax hartzii Rosenv., which was in the same genetic species group as its host Coccotylus truncatus (Pall.) M. J. Wynne et N. J. Heine and is thus transferred to Coccotylus, C. hartzii (Rosenv.) comb. nov., but retained as a distinct species owing to its unique habit and phenology. Our results revealed the presence of cryptic diversity within the genera Coccotylus, Mastocarpus, Ozophora, and Stenogramme, for which we resurrect Coccotylus brodiei (Turner) Kütz. and describe Mastocarpus pachenicus sp. nov., Ozophora lanceolata sp. nov., and Stenogramme bamfieldiensis sp. nov., leaving a multitude of unnamed Mastocarpus spp. in need of further taxonomic study. In addition, we report range extensions into British Columbia of Besa papillaeformis Setch., previously known only from its type and nearby localities in California; Gymnogongrus crenulatus (Turner) J. Agardh, recorded only from the Atlantic; and Stenogramme cf. rhodymenioides Joly et Alveal, previously only known from South America. Finally, the phylogenetic affinities of the Canadian species of Phyllophoraceae characterized in this study were investigated using LSU rDNA, RUBISCO LSU ( rbcL), and combined analyses. [ABSTRACT FROM AUTHOR]

Accurate identification of many red algae to the species level using only morphological characters can be difficult. The emerging field of “molecular-assisted alpha taxonomy” can greatly alleviate this issue. In this approach, a large number of specimens are sequenced for a standard DNA marker as a first step to genetic species assignment, followed by detailed morphological observations. Regions of both the mitochondrial cytochrome c oxidase I gene (COI-5P) and the plastid 23S rRNA gene (UPA) have been proposed as DNA barcode markers to accomplish this task. We compared the utility of each marker as a species identification tool using members of the marine red algal family Kallymeniaceae from British Columbia, Canada. Our results indicate that COI-5P is a more sensitive marker for delimiting species, but that it can be difficult to acquire clean amplification products for many isolates of Kallymeniaceae, owing to biological contamination. This problem can be overcome by using specific primers. UPA, on the other hand, has universal primers that work in diverse lineages (e.g., red, brown, and green algae), but lower interspecific sequence variation, which has the potential to underestimate species diversity, although this was not observed in our study. During our survey, we uncovered a new species of the Kallymeniaceae, Euthora timburtonii Clarkston et G.W. Saunders sp. nov., which we describe here. [ABSTRACT FROM AUTHOR]

454 GS FLX Titanium sequencing data were used to obtain the complete mitochondrial genome ofCalliarthron tuberculosum(26,469 bp). The mitogenome contains 44 genes, including 2 ribosomal RNA, 19 transfer RNA, 5 ribosomal proteins, 1 ymf, 2 open reading frames (ORFs) and 16 genes involved in cellular respiration. The secY and rps12 are overlapped by 69 bp. rps3 and rpl16 also have a 45 bp overlapped region. Except for open reading frames near stem-loop region, the results showCalliarthron tuberculosummtDNA has a high similarity with other Florideophyceae algae mitogenomes in gene synteny, structure and gene content. Phylogeny analysis indicates a close genetic relationship ofCalliarthron tuberculosumwithSporolithon durum. [ABSTRACT FROM AUTHOR]

Systematics of the red algal order Rhodymeniales was investigated using combined large-subunit nuclear ribosomal DNA (LSU) and elongation factor 2 (EF2) analyses. These data were subjected to distance, parsimony, and Bayesian analyses, and the resulting phylogenies were largely congruent with previously published SSU results in that the four currently recognized rhodymenialean families (Champiaceae, Faucheaceae, Lomentariaceae, and Rhodymeniaceae) were resolved as monophyletic lineages (with the exception of Coelothrix, which is here transferred to the Champiaceae from the Rhodymeniaceae). In addition, taxa presently considered as incertae sedis consisted of two lineages ( Fryeella lineage and Hymenocladia lineage). Based on these results, two new families are proposed: (i) the Fryeellaceae fam. nov. to accommodate the genera Fryeella, Hymenocladiopsis, and a new taxon from Tasmania, Australia; and (ii) the Hymenocladiaceae fam. nov., to accommodate Asteromenia, Hymenocladia, and Erythrymenia. In addition to resolving familial relationships, these analyses resolved some novel interspecific affinities, and we propose a new genus, Neogastroclonium gen. nov., for Gastroclonium subarticulatum, a species that differs significantly in both morphology and molecular data from genuine species of Gastroclonium. Relationships among additional faucheacean and lomentariacean taxa were investigated using LSU data only, and these results are discussed. The familial classification of the Rhodymeniales proposed herein is discussed in light of vegetative and reproductive anatomy, most notably the ontogeny of the tetrasporangia. [ABSTRACT FROM AUTHOR]

The field of DNA barcoding is working towards generating a genetic system for the quick and accurate identification of eukaryotic species. For the more systematic minded, however, DNA barcoding offers a new approach towards screening and uniting large numbers of biological specimens in genetic groups as a first step towards assigning them to species and genera in an approach best termed “molecular-assisted alpha taxonomy”. This approach is particularly amenable in organisms with simple morphologies, a propensity for convergence, extensive phenotypic plasticity, and life histories with an alternation of heteromorphic generations. It is hard to imagine a group of organisms better defined by all of these traits than the marine macroalgae. In an effort to assess the utility of the DNA barcode (COI-5′) for testing the current concepts of biodiversity of marine macroalgae in Canada, a study to assess species diversity in the red algal family, Dumontiaceae, was initiated. Through this work I confirm the presence in Canadian waters of Dilsea californica (J. Agardh) Kuntze, Dilsea integra (Kjellman) Rosenvinge, and Neodilsea borealis (I.A. Abbott) Lindstrom of the Dilsea–Neodilsea complex, and Weeksia coccinea (Harvey) Lindstrom for the genus Weeksia. However, our work has uncovered two additional species of the former complex, Dilsea lindstromiae Saunders sp. nov. and Dilsea pygmaea (Setchell) Setchell, and an additional species of the latter, Weeksia reticulata Setchell, effectively doubling representation of these foliose dumontiacean genera in Canadian waters. [ABSTRACT FROM AUTHOR]

A filamentous 'acrochaetioid' red algal epiphyte on Posidonia from Madagascar was isolated into culture. It reproduces solely by monosporangia and the spherical spores have gliding motility that differs from amoeboid spore motility seen with time-lapse video microscopy in most Acrochaetiales and Colaconematales. Electron microscopy reveals that a peripheral encircling thylakoid is absent in the chloroplast, Golgi bodies are associated with mitochondria, and pit plugs have platelike outer and inner caps and lack a cap membrane. Low-molecular-weight carbohydrates are floridoside and trehalose. Molecular evidence (small subunit, large subunit and EF2 sequences) resolved this taxon as a completely novel lineage of the Nemaliophycidae, and it is here described as Rhodachlya madagascarensis J.A. West et al., gen. et sp. nov. In light of the unusual combination of ultrastructural features and the lack of affinity to any of the currently recognized families and orders in molecular analyses, this alga forms the basis of a new family, Rhodachlyaceae G.W. Saunders et al., fam. nov., and order, Rhodachlyales G.W. Saunders et al., ord. nov., of the subclass Nemaliophycidae. [ABSTRACT FROM AUTHOR]

Abstract: Previous studies have indicated that resolution of supraordinal relationships in the red algal class Florideophyceae will require additional characters, improved taxon sampling and optimized methods of phylogenetic analysis. To this end, we have generated data to introduce a novel nuclear marker to red algal systematics, elongation factor 2, as well as expanded ribosomal DNA alignments (SSU and LSU) to include 62 ingroup and 4 outgroup taxa. Both single gene and combined data sets were considered. Our analyses resulted in better resolution of both deep as well as more recent divergences, with higher support realized at many nodes. Distance, parsimony and bayesian analyses of the single gene and combined data sets indicated that the subclasses Hildenbrandiophycidae, Ahnfeltiophycidae and Rhodymeniophycidae were monophyletic, whereas the Nemaliophycidae was polyphyletic: one lineage containing the Rhodogorgonales and Corallinales (CR complex); and the other containing the Acrochaetiales, Balbianiales, Balliales, Batrachospermales, Colaconematales, Nemaliales, Palmariales, and Thoreales (APB complex). Based on these results a new subclass of the Florideophyceae, the Corallinophycidae subclassis nov., is proposed to accommodate the Corallinales and Rhodogorgonales. In addition to resolving supraordinal relationships, the present analyses resolved some novel ordinal affinities within the Nemaliophycidae and Rhodymeniophycidae, which are discussed here. [Copyright &y& Elsevier]

We present a contemporary monograph of the poorly known red algal genus Leptofauchea and provide a list of diagnostic features to distinguish it from other rhodymenialean genera. Of six species included in this genus at the time of initiating this study, we accept only the type species Leptofauchea nitophylloides (J. Agardh) Kylin, L. rhodymenioides W.R. Taylor, and L. pacifica E.Y. Dawson. To these we add a new species of Leptofauchea, L. chiloensis sp. nov., which we collected on repeated trips to the Golfo de Ancud, Isla Grande de Chiloé, Chile. An additional species from Western Australia (‘L. anastomosans’ sensu Huisman) is acknowledged, but we had insufficient material to describe adequately this entity. Leptofauchea brasiliensis Joly is shown to be a likely species of the Phyllophoraceae, Gigartinales, while the recently described L. earleae Gavio & Fredericq lacks diagnostic features of the genus—both species are here excluded from the genus. Material was not available for L. auricularis E.Y. Dawson, and we thus cannot confirm its taxonomic position. We have also studied South African specimens traditionally assigned to ‘L. anastomosans’ sensu R.E. Norris & Aken (a specific epithet correctly assigned to Australian and Indonesian specimens referable to the genus Asteromenia) and conclude that they are not representative of Leptofauchea. Molecular analyses indicate that the genus Leptofauchea, as recognized here, represents a distinct lineage within the rhodymenialean family Faucheaceae, where it is sister to the genus Webervanbossea. [ABSTRACT FROM AUTHOR]

Published phylogenies based on nuclear small-subunit (SSU) ribosomal DNA have largely failed to resolve ordinal relationships within the Rhodymeniophycidae. Of the nine orders currently recognized, SSU analyses only consistently resolved an association between the Halymeniales and Rhodymeniales. This situation was confounded by an unexpected association between the Rhodymeniales and Gracilariales shown in published combined SSU + LSU (large subunit ribosomal DNA) phylogenies. To investigate this conundrum further, nuclear SSU and LSU sequences were determined to produce a comprehensive combined data set of 61 ingroup taxa, representing 22 families within the Rhodymeniophycidae, emphasizing disparate lineages of the Gigartinales sensu lato. Molecular phylogenies were constructed from individual gene and combined data sets in an effort to achieve increased ordinal resolution. The new analyses realized little increased resolution among the orders, but they did resolve the conflicting taxonomic affinities of the Rhodymeniales indicating that they ally with the Halymeniales and not the Gracilariales. The latter order was affiliated to the Nemastomatales in all SSU-only analyses, as well as for SSU + LSU combined Bayesian results with the covarion option invoked. In addition, the resulting phylogenetic hypotheses have shed light on the taxonomic associations of a few rogue families of the Gigartinales sensu lato. Notably, the Acrosymphytaceae failed to join other families of the Gigartinales and we therefore propose the Acrosymphytales ord. nov. to accommodate this family. The Sebdeniaceae was generally weakly allied as sister to the Rhodymeniales rather than with the Halymeniales where it is currently placed. Owing to its consistently equivocal placement in contemporary molecular analyses, as well as a suite of anatomical characters intermediate between the Halymeniales sensu stricto and Rhodymeniales, we here propose the Sebdeniales ord. nov. [ABSTRACT FROM AUTHOR]

The senior author was fortunate in 1996 to dive on the remote Houtman Abrolhos Islands of Western Australia and view in situ the stunning “Asteromenia peltata” that is so strikingly illustrated by John Huisman (viewable on AlgaeBase). Five years later, during excursions to Bermuda and Lord Howe Island (tropical eastern Australia), he observed and collected specimens referable to this species in both these localities. Based on their respective appearances in the field, it seemed unlikely that these entities from geographically remote regions represented the same species. Our molecular results not only confirm this suspicion, but further indicate that A. peltata sensu lato constitutes a complex of at least five distinct species. We restrict A. peltata to one of two species found in the western (sub)tropical North Atlantic, the second described herein as A. bermudensis sp. nov. Samples from Western Australia represent an undescribed species, A. exanimans sp. nov., while two entities collected from Lord Howe Island (A. anastomosans (Weber-van Bosse) comb. nov. and A. pseudocoalescens sp. nov.) conform to records variously reported as Asteromenia peltata and Drouetia coalescens. Specimens of D. coalescens from South Africa are also not representative of the genus Drouetia, but form a novel lineage within the Rhodymeniaceae. We included two species of Halichrysis in our molecular analyses and, in combination with observations of salient anatomical features, provide arguments for maintaining Asteromenia, Drouetia, and Halichrysis as distinct genera. [ABSTRACT FROM AUTHOR]

Previous phylogenetic studies of the Rhodophyta have provided a framework for understanding red algal phylogeny, but there still exists the need for a comprehensive analysis using a broad sampling of taxa and sufficient phylogenetic information to clearly define the major lineages. In this study, we determined 48 sequences of the PSI P700 chl a apoprotein A1 ( psaA) and rbcL coding regions and established a robust red algal phylogeny to identify the major clades. The tree included most of the lineages of the Bangiophyceae (25 genera, 48 taxa). Seven well-supported lineages were identified with this analysis with the Cyanidiales having the earliest divergence and being distinct from the remaining taxa; i.e. the Porphyridiales 1–3, Bangiales, Florideophyceae, and Compsopogonales. We also analyzed data sets with fewer taxa but using seven proteins or the DNA sequence from nine genes to resolve inter-clade relationships. Based on all of these analyses, we propose that the Rhodophyta contains two new subphyla, the Cyanidiophytina with a single class, the Cyanidiophyceae, and the Rhodophytina with six classes, the Bangiophyceae, Compsopogonophyceae, Florideophyceae, Porphyridiophyceae classis nov. (which contains Porphyridium, Flintiella, and Erythrolobus), Rhodellophyceae, and Stylonematophyceae classis nov. (which contains Stylonema, Bangiopsis, Chroodactylon, Chroothece, Purpureofilum, Rhodosorus, Rhodospora, and Rufusia). We also describe a new order, Rhodellales, and a new family, Rhodellaceae (with Rhodella, Dixoniella, and Glaucosphaera). [ABSTRACT FROM AUTHOR]

The molecular phylogeny of red algal actin genes, with emphasis on the paraphyletic “Bangiophyceae,” was examined and compared to the rhodophyte SSU rDNA phylogeny. Nineteen new genomic actin sequences and seven SSU rDNA sequences were obtained and subjected to diverse phylogenetic analyses (maximum likelihood, distance/neighbor-joining, maximum parsimony, Bayesian analyses, and, with respect to protein sequences, also quartet puzzling). The actin trees confirmed most of the major clades found in the SSU rDNA phylogenies, although with a lower resolution. An actin gene duplication in the florideophycean lineage is reported, presumably related to an increased complexity of sexual reproduction. In addition, the distribution and characteristics of spliceosomal introns found in some of the actin sequences were examined. Introns were found in almost all florideophycean actin genes, whereas only two bangiophyte sequences contained introns. One intron in the florideophycean actin genes was also found in metazoan, and, shifted by one or two nucleotides, in a glaucocystophyte, a cryptophyte, and two fungal actin genes, and thus may be an ancient intron. [ABSTRACT FROM AUTHOR]

The Plocamiaceae currently includes two genera: the free-living Plocamium and the adelphoparasite, Plocamiocolax. Plocamium includes ca. 40 species that are widely distributed throughout the world's oceans. Most species are clearly defined anatomically and biogeographically; however, the type species Plocamium cartilagineum (type locality: considered northern Europe) is an exception. Although reportedly cosmopolitan in distribution, our investigations unequivocally indicate that there is substantial genetic diversity among isolates from different geographic locations and that there are at least eight divergent cryptic species currently included in P. cartilagineum. In this investigation we focused on populations of P. cartilagineum from northern Europe. We used a combination of molecular and morphological characters in order to establish boundaries between four cryptic species in this geographical area. Our molecular results not only resolve these four entities as distinct, but also indicate that they are among the most divergent of all Plocamium species worldwide. As a result, we now recognize P. cartilagineum, Plocamium subtile, Plocamium nanum sp. nov. and Plocamium maggsiae sp. nov. in northern Europe. A preliminary assessment of ‘ P. cartilagineum ' in other geographical areas is provided. [ABSTRACT FROM AUTHOR]

Solid-state 13 C nuclear magnetic resonance (NMR) and wide-angle X-ray scattering (WAXS) were used to characterise the cellulose in six species of Florideophycean algae. NMR identified cellulose I ß as the dominant crystalline form in all species, and was used to estimate the widths of the sheets of cellulose chains. The mean value (±SD) was 3.9±0.4 nm. WAXS was used to estimate the thickness of microfibrils measured normal to the sheets of chains. The mean value (±SD) was 1.9±0.5 nm. Uniformity of these results across the six species supported a generalisation that Florideophycean algae biosynthesise cellulose chains in microfibrils that are narrower than those biosynthesised by Bangiophycean algae. [ABSTRACT FROM AUTHOR]

Phosphatic sediments of the Late Neoproterozoic (ca. 600 million years old [Myr]) Doushantuo Formation at Weng'an, South China, contain fossils of multicellular algae preserved in anatomical detail. As revealed by light microscopy and scanning electron microscopy, these fossils include both simple pseudoparenchymatous thalli with apical growth but no cortex-medulla differentiation and more complex thalli characterized by cortex medulla differentiation and structures interpretable as carposporophytes, suggesting a multiphasic life cycle. Simple pseudoparenchymatous thalli, represented by Wengania, Gremiphyca, and Thallophycoides, are interpreted as stem group florideophytes. In contrast, complex pseudoparenchymatous thalli, such as Thallophyca and Paramecia, compare more closely to fossil and living corallinaleans than to other florideophyte orders, although they also differ in some important aspects (e.g., lack of biocalcification). These more complex thalli are interpreted as early stem group corallinaleans that diverged before Paleozoic stem groups such as Arenigiphylum, Petrophyton, Graticula, and Archaeolithophyllum. This phylogenetic interpretation implies that (1) the phylogenetic divergence between the Florideophyceae and its sister group, the Bangiales, must have taken place before Doushantra) time—an inference supported by the occurrence of bangialean fossils in Mesoproterozoic rocks; (2) the initial diversification of the florideophytes occurred no later than the Doushantuo time: and (3) the corallinalean clade had a "soft" (uncalcified) evolutionary history in the Neoproterozoic before evolving biocalcification in the Paleozoic and undergoing crown group diversification in the Mesozoic. [ABSTRACT FROM AUTHOR]

Nuclear small-subunit ribosomal DNA sequences were determined for 65 members of the Gigartinales and related orders. With representatives of 15 families of the Gigartinales sensu Kraft and Robins included for the first time, our alignment now includes members of all but two of the ca. 40 families. Our data continue to support ordinal status for the Plocamiales, to which we provisionally transfer the Pseudoanemoniaceae and Sarcodiaceae. The Halymeniales is retained at the ordinal level and consists of the Halymeniaceae (including the Corynomorphaceae), Sebdeniaceae, and Tsengiaceae. In the Halymeniaceae, Grateloupia intestinalis is only distantly related to the type species, Grateloupia filicina, but is closely affiliated with the genus Polyopes. The Nemastomatales is composed of the Nemastomataceae and Schizymeniaceae. The Acrosymphytaceae (now including Schimmelmannia, formerly of the Gloiosiphoniaceae) and the Calosipho niaceae (represented by Schmitzia) have unresolved affinities and are considered as incertae sedis among lineage 4 orders. We consider the Gigartinales sensu stricto to include 29 families, although many contain only one or a few genera and mergers will probably result following further investigation. Although the small-subunit ribosomal DNA was generally too conservative to resolve family relationships within the Gigartinales sensu stricto, a few key conclusions are supported. The Hypneaceae, questionably distinct from the Cystocloniaceae on anatomical grounds, is now subsumed into the latter family. As recently suggested, the Wurdemanniaceae should be incorporated into the Solieriaceae, but the latter should not be merged with the Areschougiaceae. The Corynocystaceae Kraft, fam. nov., is described and added to the Gigartinales sensu stricto. [ABSTRACT FROM AUTHOR]

Two new species of the red algal genus Predaea are described from Australia. The first, Predaea aurora Kraft et G.W. Saunders, sp. nov., is unusual in its cool-temperate distribution and in a number of anatomical attributes, most notably the rhizoid-like habit of the nutritive filaments associated with the auxiliary cells. The second species, Predaea tumescens Kraft et G.W. Saunders, sp. nov., inhabits a coral reef habitat more typical of the genus but nonetheless differs in a number of anatomical details from other reported species. Nuclear small subunit rDNA sequences have confirmed the affinity of P. aurora to other species currently included in this genus. Molecular analyses further indicate that Predaea belongs in the Nemastomataceae and that the Nemastomataceae and Schizymeniaceae are sister taxa in an independent clade of “lineage 4” florideophyte algae. As such, a proposal is made to resurrect the Nemastomatales Kylin emend. G.W. Saunders et Kraft to accommodate these two families. Within the Schizymeniaceae, the Australian-endemic Platoma australicum and Platoma foliosum were only distantly related to the other included Platoma , Schizymenia , and Titanophora spp. We therefore propose Wetherbeella G.W. Saunders et Kraft, gen. nov., to accommodate these two species. An additional outcome of our molecular analyses is that the genus Tsengia is not a member of the Nemastomataceae (where it is currently placed) but rather forms an independent lineage in the Halymeniales that we now designate as the Tsengiaceae G.W. Saunders et Kraft, fam. nov. Finally, the South African Nemastoma lanceolatum J. Agardh is transferred to Tsengia. [ABSTRACT FROM AUTHOR]

Two new species of the red algal genus Predaea are described from Australia. The first, Predaea aurora Kraft et G.W. Saunders, sp. nov., is unusual in its cool-temperate distribution and in a number of anatomical attributes, most notably the rhizoid-like habit of the nutritive filaments associated with the auxiliary cells. The second species, Predaea tumescens Kraft et G.W. Saunders, sp. nov., inhabits a coral reef habitat more typical of the genus but nonetheless differs in a number of anatomical details from other reported species. Nuclear small subunit rDNA sequences have confirmed the affinity of P. aurora to other species currently included in this genus. Molecular analyses further indicate that Predaea belongs in the Nemastomataceae and that the Nemastomataceae and Schizymeniaceae are sister taxa in an independent clade of “lineage 4” florideophyte algae. As such, a proposal is made to resurrect the Nemastomatales Kylin emend. G.W. Saunders et Kraft to accommodate these two families. Within the Schizymeniaceae, the Australian-endemic Platoma australicum and Platoma foliosum were only distantly related to the other included Platoma , Schizymenia , and Titanophora spp. We therefore propose Wetherbeella G.W. Saunders et Kraft, gen. nov., to accommodate these two species. An additional outcome of our molecular analyses is that the genus Tsengia is not a member of the Nemastomataceae (where it is currently placed) but rather forms an independent lineage in the Halymeniales that we now designate as the Tsengiaceae G.W. Saunders et Kraft, fam. nov. Finally, the South African Nemastoma lanceolatum J. Agardh is transferred to Tsengia. [ABSTRACT FROM AUTHOR]

Sequence data are presented for approximately 85% of the nuclear large subunit (LSU) rDNA gene for one member of the Bangiophyceae and 47 members of the Florideophyceae, the latter representing all but one of the currently recognized florideophyte orders. Distance, parsimony, and maximum likelihood analyses of these data were used to generate phylogenetic trees, and bootstrap resampling was implemented to infer robustness for distance and parsimony results. LSU phylogenies were congruent with published nuclear small subunit (SSU) rDNA results in that four higher level florideophyte lineages were resolved: lineage 1, containing the order Hildenbrandiales; lineage 2, recovered only under distance analysis, composed of the orders Acrochaetiales, Balliales, Batrachospermales, Corallinales, Nemaliales, Palmariales, and Rhodogorgonales; lineage 3, containing the Ahnfeltiales; and lineage 4, composed of the orders Bonnemaisoniales, Ceramiales, Gelidiales, Gigartinales, Gracilariales, Halymeniales, Plocamiales, and Rhodymeniales. Analyses were also performed on a combined LSU–SSU data set and an SSU-only data set to account for differences in taxon sampling relative to published studies using this latter gene. Combined LSU–SSU analyses resulted in phylogenetic trees of similar topology and support to those obtained from LSU-only analyses. Phylogenetic trees produced from SSU-only analyses differed somewhat in particulars of branching within lineages 2 and 4 but overall were congruent with the LSU-only and combined LSU–SSU results. We close with a discussion of the phylogenetic potential that the LSU has displayed thus far for resolving relationships within the Florideophyceae. [ABSTRACT FROM AUTHOR]

We sequenced the complete mitochondrial genome of Gracilariopsis chorda (Gracilariales, Rhodophyta), which is an agar-producing economic red algal species distributed in the northwest Pacific. The mitogenome is 26,534 bp in length with 27.7% GC content that consists of 52 genes including 26 protein-coding, 2 rRNA and 24 tRNA genes. We compared G. chorda mitogenome with that of recently published G. lemaneiformis. Nucleotide sequence similarity between these two mitogenomes was 99.82%, however, there was significant difference in length caused by trnR trnS and trnY genes missing in G. lemaneiformis. [ABSTRACT FROM AUTHOR]