Genetic and morphological analyses of Gracilaria firma and G. changii (Gracilariaceae, Rhodophyta), the commercially important agarophytes in western Pacific

Many studies classifying Gracilaria species for the exploitation of agarophytes and the development of the agar industry were conducted before the prevalence of molecular tools, resulting in the description of many species based solely on their morphology. Gracilaria firma and G. changii are among the commercially important agarophytes from the western Pacific; both feature branches with basal constrictions that taper toward acute apices. In this study, we contrasted the morpho-anatomical circumscriptions of the two traditionally described species with molecular data from samples that included representatives of G. changii collected from its type locality. Concerted molecular analyses using the rbcL and cox1 gene sequences, coupled with morphological observations of the collections from the western Pacific, revealed no inherent differences to support the treatment of the two entities as distinct taxa. We propose merging G. changii (a later synonym) into G. firma and recognize G. firma based on thallus branches with abrupt basal constrictions that gradually taper toward acute (or sometimes broken) apices, cystocarps consisting of small gonimoblast cells and inconspicuous multinucleate tubular nutritive cells issuing from gonimoblasts extending into the inner pericarp at the cystocarp floor, as well as deep spermatangial conceptacles of the verrucosatype. The validation of specimens under different names as a single genetic species is useful to allow communication and knowledge transfer among groups from different fields. This study also revealed considerably low number of haplotypes and nucleotide diversity with apparent phylogeographic patterns for G. firma in the region. Populations from the Philippines and Taiwan were divergent from each other as well as from the populations from Malaysia, Thailand, Singapore and Vietnam. Establishment of baseline data on the genetic diversity of this commercially important agarophyte is relevant in the context of cultivation, as limited genetic diversity may jeopardize the potential for its genetic improvement over time

Chloroplast genomes as a tool to resolve red algal phylogenies: a case study in the Nemaliales

Obtaining strongly supported phylogenies that permit confident taxonomic and evolutionary interpretations has been a challenge in algal biology. High-throughput sequencing has improved the capacity to generate data and yields more informative datasets. We sequenced and analysed the chloroplast genomes of 22 species of the order Nemaliales as a case study in the use of phylogenomics as an approach to achieve well-supported phylogenies of red algae.Australian Research Council/[FT110100585]/ARC/AustraliaAustralian Biological Resources Study/[RFL213-08]/ABRS/AustraliaMillennium Scientific Initiative/[NC120030]/MSI/Nueva JerseyUniversity of Melbourne///AustraliaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

Molecular phylogeny and developmental studies of Apoglossum and Paraglossum (Delesseriaceae, Rhodophyta) with a description of Apoglosseae trib. nov

Our morphological and molecular studies indicate that species from the southern hemisphere previously placed in Delesseria belong in Paraglossum and that Paraglossum and Apoglossum comprise a separate tribe, the Apoglosseae, S.-W. Lin, Fredericq & Hommersand, trib. nov., within the family Delesseriaceae. From a vegetative perspective the Apoglosseae is readily recognized because some or all fourth-order cell rows are formed on the inner sides of third-order cell rows. All fourth-order cell rows grow adaxially in Apoglossum, whereas both adaxial and abaxial cell rows are present in Paraglossum. Periaxial cells do not divide in Apoglossum, whereas they divide transversely in Paraglossum in the same way as in Delesseria. Major branches are formed mainly from the margins of midribs in the Apoglosseae. The procarp consists of a straight carpogonial branch and two sterile cells, with the second formed on the same side as the first. The carpogonium cuts off two connecting cells in tandem from its apical end, the terminal cell being nonfunctional and the subterminal cell typically fusing with the auxiliary cell. Gonimoblast filaments radiate in all directions from the gonimoblast initials and produce carposporangia terminally in branched chains, with pit connections between the inner gonimoblast cells broadening and enlarging. The auxiliary cell, supporting cell, and sterile cells unite into a fusion cell, which remains small in Apoglossum but incorporates the branched inner gonimoblast filaments and cells in the floor of the cystocarp in Paraglossum. Elongated inner cortical cells seen in mature cystocarps in the Delesserieae are absent in the Apoglosseae. Phylogenetic studies based on rbcL (RuBisCO large subunit gene) sequence analyses strongly support the recognition of the Apoglosseae within the subfamily Delesserioideae of the Delesseriaceae, in agreement with our previous observations based primarily on analyses of large subunit ribosomal DNA (LSU)

Systematic revision of the genus <i>Reinboldiella</i> (Ceramiaceae, Rhodophyta) from Taiwan based on comparative morphology and <i>rbc</i>L sequence analyses, including two new species of <i>Reinboldiella</i>

<p>The genus <i>Reinboldiella</i> essentially consists of tiny, membranous blades, epiphytic on benthic red algae, with a wide distribution in the north-western Pacific Ocean (Taiwan, Korea and Japan). In this study, we re-examined the generitype <i>R. schmitziana</i> from Taiwan and neighbouring islands. Two new species of <i>Reinboldiella, R. orientalis</i> sp. nov. and <i>R. taiwanensis</i> sp. nov. are recognized from Taiwan based on comparative morphological studies and molecular analyses of RuBisCO large subunit (<i>rbc</i>L) gene sequences. <i>Reinboldiella</i> <i>orientalis</i> is characterized by its rosette-like appearance, with both erect and prostrate, membranous flat blades whereas <i>R. taiwanensis</i> is distinguishable by mainly consisting of erect, membranous blades with few, short prostrate blades in basal parts of the thalli. Thalli of <i>R. schmitziana</i> also have a rosette-like appearance, but their erect flat blades have cylindrical bases or stipes. The <i>rbc</i>L phylogenetic analyses also support the separation of <i>R.</i>‘<i>schmitziana</i>’ from Taiwan and <i>R. schmitziana</i> from Japan and Korea.</p

Two Marine Brown Algae (Phaeophyceae) New to Pratas Island

Two marine brown algae, Cladosiphon okamuranus Tokida and Stypopodium flabelliforme Weber-van Bosse, are reported from Pratas Island for the first time. Diagnostic morphological features are illustrated and the taxonomic status of the two species is also discussed

Une nouvelle espèce aplatie de &lt;I&gt;Gracilaria&lt;/I&gt; (Gracilariales, Rhodophyta) récoltée à Taiwan

Une espèce nouvelle de Gracilaria, G. huangii est décrite du sud de l\u27île de Taïwan. Gracilaria huangii est principalement caractérisée par de nombreux lobes ou feuillets le long des marges et sur la surface des lames, et une absence ou presque-absence des cellules nutritives tubulaires. L\u27analyse moléculaire basée sur le rbcL des espèces aplaties avec les marges épineuses et les conceptacles spermatangiaux de type textorii appuie la proposition de cette nouvelle espèce.A new, flattened species of Gracilaria, G. huangii, is described from southern Taiwan in the warm water region of the west Pacific Ocean. Gracilaria huangii is mainly characterized by numerous lobes or bladelets along the margins and on the surface of the blades, and a lack or near absence of tubular nutritive cells. The molecular analysis based on the plastid encoded rbcL gene of the flattened species with spiny margins and the textorii -type spermatangial conceptacles supports the proposal of this new species.</p

Systematic revision of the widespread species Sarcodia ceylanica (Sarcodiaceae, Rhodophyta) in the Indo-Pacific Oceans, including S. suiae sp. nov.

The marine red algal genus Sarcodia possesses single to several flattened blades, composed of a central layer of medullary filaments, with some stellate cells remaining, flanked by two layers of subspherical to stellate cortical cells. Among the described species, S. ceylanica, previously regarded as a synonym of S. montagneana, is characterised by erect thalli composed of subdichotomously branched blades and has been widely reported from the Indian and western Pacific Oceans. Collections from various localities in the Indo-Pacific regions included many specimens fitting this broad concept of S. ceylanica but differed in blade morphology and were difficult to assign to any named species with confidence. In order to delineate the species boundaries within the suite of the specimens that morphologically resemble S. ceylanica and to clarify the phylogenetic significance of the morphological features used for separating species of Sarcodia, we used rbcL sequences to infer phylogenetic relationships among the available specimens. RbcL sequence analyses showed that the distribution of S. ceylanica is most likely restricted to its type locality Sri Lanka. The collections of S. 'ceylanica' analysed from Taiwan, Japan and Kenya were split into four clades and were genetically different from those collections of S. ceylanica from Sri Lanka. The molecular results also suggested that S. montagneana is distributed only in New Zealand. In addition, one new species, S. suiae S.-M. Lin & Rodriguez-Prieto, is described to accommodate specimens of S. 'ceylanica' from Taiwan. Records of S. 'ceylanica' and S. 'montagneana' from other locations in the Indo-Pacific regions should be regarded as doubtful until detailed morphological studies and molecular analyses of freshly collected specimens become available

Systematics and biogeography of the red algal genus Yonagunia (Halymeniaceae, Rhodophyta) from the Indo-Pacific including the description of two new species from Taiwan

Carpopeltis maillardiihas been regarded as a widely distributed species in the Indo-Pacific region. In this study, we analyzed the genetic diversity ofC. maillardiiand related species collected from Taiwan and the Indian Ocean based onrbcL sequences, in order to elucidate species boundaries, diversity, and biogeographic patterns. Our analyses show thatC. maillardiispecimens are only distantly related to the genusCarpopeltis(type:C. phyllophora) but instead form a clade together with species ofYonagunia. We therefore propose the new combinationYonagunia maillardiicomb. nov. In addition, two new species (Yonagunia palmatasp. nov. andYonagunia taiwani-borealissp. nov.) are described from Taiwan. The close relationship ofYonaguniatoGrateloupiais corroborated by detailed observations of the female reproductive structures, which demonstrate that the development of auxiliary cell ampullae before and after diploidization is similar to that ofGrateloupiasensu stricto. Namely, the ampullae are composed of only two orders of unbranched filaments in which only a few ampullar cells are incorporated into a basal fusion cell after diploidization of the auxiliary cell and the pericarp consists almost entirely of secondary medullary filaments. Of allYonaguniaspecies,Y. maillardiihas the widest distribution in the Indo-Pacific, and can be identified in the field by its relatively thin, feathery, and highly branched morphology. Most other species, including those that occur in Taiwan, are seemingly more range-restricted. Our phylogenetic analyses resulted in a well-resolved phylogeny ofYonagunia, with an origin estimated in the Eocene-Oligocene, and diversification of species mainly in the Miocene