Evidence for the treatment of Talarodictyon tilesii as an older taxonomic synonym of Hydroclathrus stephanosorus (Scytosiphonaceae, Phaeophyceae)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147209/1/pre12348_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147209/2/pre12348.pd

Cryptic Haploid Stages in the Life Cycle of Leathesia marina (Chordariaceae, Phaeophyceae) Under In Vitro Culture

We evaluated the life cycle of Leathesia marina through molecular analyses, culture studies, morphological observations, and ploidy measurements. Macroscopic sporophytes were collected from two localities in Atlantic Patagonia and were cultured under long-day (LD) and short-day (SD) conditions. Molecular identification of the microscopic and macroscopic phases was performed through the cox3 and rbcL genes and the phylogeny was assessed on the basis of single gene and concatenated datasets. Nuclear ploidy of each phase was estimated from the DNA contents of individual nuclei through epifluorescence microscopy and flow cytometry. Molecular results confirmed the identity of the Argentinian specimens as L. marina and revealed their conspecificity with L. marina from New Zealand, Germany, and Japan. The sporophytic macrothalli (2n) released mitospores from plurilocular sporangia, which developed into globular microthalli (2n), morphologically similar to the sporophytes but not in size, constituting a generation of small diploid thalli, with a mean fluorescent nuclei cross-sectional area of 3.21 ± 0.7 μm2. The unilocular sporangia released meiospores that developed two morphologically different types of microthalli: erect branched microthalli (n) with a nuclear area of 1.48 ± 0.07 µm2 that reproduces asexually, and prostrate branched microthalli (n) with a nuclear area of 1.24 ± 0.10 µm2 that reproduces sexually. The prostrate microthalli released gametes in LD conditions, which merged and produced macroscopic thalli with a nuclear cross-sectional area of 3.45 ± 0.09 µm2. Flow cytometry confirmed that the erect and prostrate microthalli were haploid and that the globular microthalli and macrothalli were diploid.Fil: Poza, Ailen Melisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Santiañez, Wilfred John E.. Hokkaido University; Japón. University of the Philippines Diliman; FilipinasFil: Croce, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Gauna, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Kogame, Kazuhiro. Hokkaido University; JapónFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

The seaweed flora of the Balabac Marine Biodiversity Conservation Corridor (BMBCC), Southern Palawan, Western Philippines

Background and aims – Studies on the diversity of the seaweed flora of the Philippines have waned in the past decades, and detailed data on the distribution of these economically important resources is missing. We attempt to bridge this gap by providing information on the diversity, distribution, and some aspects of the ecology of the seaweed flora of a marine biodiversity corridor in the western Philippines, the Balabac Marine Biodiversity Conservation Corridor (BMBCC). Methods – In seventeen stations of the BMBCC, seaweed floras were assessed. All seaweeds encountered were identified in situ, down to species level, when possible. All unidentified specimens were collected and identified in the laboratory. Cluster analysis based on Jaccard index was used to infer similarities among the seaweed floristic components of each station. A comprehensive checklist was made using data from this study and other available literature. Key results – There were 176 seaweed species in the area (Chlorophyceae: 70 spp., Rhodophyceae: 75 spp., and Phaeophyceae: 31 spp.). Cluster analysis showed a separation between the seaweed flora of areas within the Sulu Sea and those of the West Philippine Sea. Similarities among the floristic components of these areas may be attributed to the resemblances in the prevailing ecological conditions (i.e. substrate, wave exposure, and water movement, among others). Conclusions – BMBCC harbours a relatively diverse seaweed flora, considering its small area. In addition, habitat characteristics, particularly the substrate type, appear to influence floristic compositions and similarities among the different surveyed areas. This report is the first to consolidate floristic information in a marine biodiversity conservation corridor in the country

FIG. 2 in Molecular-assisted taxonomic study on the Sargassum C.Agardh (Fucales, Phaeophyceae) in northwestern Luzon, Philippines

FIG. 2. — Maximum likelihood tree of Sargassum C.Agardh from northwestern Philippines based on cox3 sequence data. Support values in the form of nonparametric bootstrap (NPBS), approximate likelihood ratio test percentages (aLRT), ultrafast bootstrap (UFBS) and Bayesian posterior probabilities (BPP) are shown at each branch. Thickened lines indicate highly supported nodes (NPBS: ≥ 90%; aLRT: ≥ 90%; UFBS: ≥ 95%; and BPP: ≥ 0.90). Values <80% (NPBS), <80% (aLRT), <80% (UFBS), and <0.80 (BPP) are removed. Specimen codes correspond to those listed in Appendix 1. Abbreviations: AU, Australia; FP, French Polynesia; KR, Korea; NC, New Caledonia; PH, Philippines; SG, Singapore; VU, Vanuatu.Published as part of <i>Santiañez, Wilfred John E., Lastimoso, John Michael L., Hoshino, Masakazu, Villafuerte, Brix Nester Q., Kogame, Kazuhiro & Gavino C. Trono, Jr, 2023, Molecular-assisted taxonomic study on the Sargassum C.Agardh (Fucales, Phaeophyceae) in northwestern Luzon, Philippines, pp. 127-142 in Cryptogamie, Algologie 20 (7)</i> on page 131, DOI: 10.5252/cryptogamie-algologie2023v44a7, <a href="http://zenodo.org/record/10020969">http://zenodo.org/record/10020969</a&gt

FIG. 4 in Molecular-assisted taxonomic study on the Sargassum C.Agardh (Fucales, Phaeophyceae) in northwestern Luzon, Philippines

FIG. 4. — Sargassum ilicifolium (Turner) C.Agardh from northwestern Philippines: A, top view of some S. ilicifolium thalli growing in the shallow subtidal of Arosan, Bolinao, Pangasinan; B, in situ photograph of a young S. ilicifolium thalli showing the wavy and toothed and occasionally "duplicated" blades (arrowhead); C, pressed herbarium specimen of S. ilicifolium from Ilocos Sur, Philippines. Portion of an axis showing several turbinariod blades (C': arrowheads); D, portion of an axis showing small, ribbed vesicles (arrowheads) growing together with blades of various shapes; E, fertile portion of a female plant showing the compressed to flattened and toothed female receptacles (arrowheads) that are closely associated with blades; F, portion of a male plant showing terete receptacles (arrowheads) that are closely associated with vesicles (arrows) and blades; G, variability of shape and form of S. ilicifolium blades, those with double rows of teeth, duplicated apical margins, and with cup-shaped/turbinarioid apices are indicated with double arrowheads, arrow, and arrowhead, respectively. Scale bars: C, 5 cm; C', E-G, 1 cm; D, 2 cm.Published as part of <i>Santiañez, Wilfred John E., Lastimoso, John Michael L., Hoshino, Masakazu, Villafuerte, Brix Nester Q., Kogame, Kazuhiro & Gavino C. Trono, Jr, 2023, Molecular-assisted taxonomic study on the Sargassum C.Agardh (Fucales, Phaeophyceae) in northwestern Luzon, Philippines, pp. 127-142 in Cryptogamie, Algologie 20 (7)</i> on page 135, DOI: 10.5252/cryptogamie-algologie2023v44a7, <a href="http://zenodo.org/record/10020969">http://zenodo.org/record/10020969</a&gt

Taxonomic reassessment of the Indo-Pacific Scytosiphonaceae (Phaeophyceae):Hydroclathrus rapanuii sp. nov. and Chnoospora minima from Easter Island, with proposal of Dactylosiphon gen. nov. and Pseudochnoospora gen. nov.

Abstract A new and putatively endemic species of Hydroclathrus, Hydroclathrus rapanuii, is described from the geographically isolated Easter Island in the southeastern Pacific based on morphological and molecular phylogenetic data. It is distinguished from other Hydroclathrus by thalli of unevenly furrowed thin membranes, and angular, block-like plurangial sori. Our phylogenetic analyses indicated that H. rapanuii is closely related to the generitype Hydroclathrus clathratus. We also report on the morphology and phylogeny of Chnoospora minima from Easter I. and elsewhere in the Indo-Pacific Ocean, noting the previously unreported presence of hollow portions in its medulla. Although not collected from Easter I., we herein propose the recognition of two new genera, Dactylosiphon gen. nov. and Pseudochnoospora gen. nov., based on our three-gene phylogeny and their known morphologies and anatomies. Dactylosiphon is based on the three species currently assigned to Colpomenia (C. bullosa, C. durvillei, and C. wynnei) that are genetically and morphologically (i.e. thalli with erect and finger-like tubes arising from a common saccate base) distinct from other members of Colpomenia. The monotypic genus Pseudochnoospora is represented by the decumbent, branching, and interadhesive species currently known as Chnoospora implexa. With the above proposals, we further increase the genus-level diversity of Scytosiphonaceae in the Indo-Pacific Ocean