• 제목/요약/키워드: Ralfsiales

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Ralfsia longicellularis (Ralfsiales, Phaeophyceae): a Far East Asian endemic brown alga from Korea

  • Oteng'o, Antony Otinga;Won, Boo Yeon
    • 환경생물
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    • 제38권1호
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    • pp.101-105
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    • 2020
  • Ralfsia longicellularis is known as an endemic species in Far East Asia. In this study, we report R. longicellularis as a new record from Korea based on morphological and molecular analyses. Molecular analyses based on plastid-encoded rbcL gene sequences and morpho-anatomical studies were undertaken on Ralfsia species, a poorly studied genus from Korea. Ralfsia longicellularis is mainly characterized by a dark brown thallus; 770-1200 ㎛ thick, curved cells in the creeping and ascending parts of the filaments; basal layer and erect filament cells with a width-to-length ratio of 1 : 1.5 to 10; narrowshaped sporangia on-stalk cells at the base of the paraphyses; and mostly uniseriate plurilocular reproductive organs capped with 1-2 sterile cells. The R. longicellularis samples from Korea in this study were similar to ones collected from the type locality (Peter the Great Bay, Russia) in morphology. The rbcL analyses also revealed that our Korean R. longicellularis samples were placed in the same clade with Russian materials, within a Ralfsia clade but distinct from the congeners.

Endoplura jejuensis sp. nov. and Endoplura koreana sp. nov. (Ralfsiales, Phaeophyceae) from Korea based on molecular and morphological analyses

  • Oteng'o, Antony Otinga;Cho, Tae Oh;Won, Boo Yeon
    • ALGAE
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    • 제36권3호
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    • pp.155-163
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    • 2021
  • The crustose brown algal genus Endoplura has been known as a monotypic genus characterized by its intercalary plurangial reproductive structures composed of 2-4 separate parallel filaments terminated by 2-5 sterile cells and by containing several to many chloroplasts per cell. In this study, Endoplura jejuensis sp. nov. and E. koreana sp. nov. from Korea are newly described based on molecular and morphological analyses. Our phylogenetic analyses of the rbcL gene reveal that E. jejuensis sp. nov. and E. koreana sp. nov. are placed in the same clade with "E. aurea" from Japan with a strong bootstrap supporting value. E. jejuensis is characterized by small and light to dark brown crustose thalli of less than 1 cm diameter, tufts of hairs arising from the basal disc, plurangia composed mostly of two separate parallel reproductive filaments terminated by 2-4 sterile cells, and sessile unangia each with a single paraphysis. E. koreana is distinguished by olive or yellowish-brown crustose thalli of up to 3 cm diameter, tufts of hairs arising from the basal disc, and apical parts of erect filaments, plurangia with 2-5 separate reproductive filaments terminated by 2-8 sterile cells, and sessile unangia with 1-2 paraphyses. Our studies also show that "E. aurea" specimens from Japan may be recognized to be a different species from other Endoplura species.

Ramipedicella gen. nov. (Ralfsiales, Phaeophyceae): a new crustose brown algal genus including two species, Ramipedicella miniloba sp. nov. and Ramipedicella longicellularis comb. nov.

  • Antony Otinga Oteng'o;Boo Yeon Won;Tae Oh Cho
    • ALGAE
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    • 제39권2호
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    • pp.97-108
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    • 2024
  • The Ralfsiaceae family, part of the Ralfsiales order and consisting of crustose brown algae, includes five genera: Analipus, Endoplura, Fissipedicella, Heteroralfsia, and Ralfsia. In this study, a novel crustose genus named Ramipedicella gen. nov. is introduced within the Ralfsiaceae based on molecular and morphological analyses. Phylogenetic analyses using both concatenated dataset (rbcL + COI-5P genes) and rbcL indicate that the crustose brown algae that we collected from Korea and Russia form a unique grouping within the Ralfsiaceae. This grouping is strongly supported by both bootstrap analysis and Bayesian posterior probabilities. The genetic differences in the rbcL and COI-5P sequences between Ramipedicella and other genera within Ralfsiaceae range from 6.7 to 9.3% for rbcL and from 15.5 to 20.8% for COI-5P. Ramipedicella is characterized by crustose thalli having new crusts growing on top of old ones with a hypothallial basal layer and erect perithallial filaments, long cells with width-to-length ratio of 1 : 1-16, single chloroplast per cell, plurangia with one to several sterile cells, one to several unangia produced from unicellular stalks or from the lateral-basal region to the paraphyses, and unangia arising sequencially in irregularly branched specialized filaments. Ramipedicella, the recently identified genus, comprises two distinct species. Ramipedicella miniloba, the type species, is distinguished by crusts with small lobes, numerous hair tufts, plurangia terminated by 1-4 sterile cells, and large oblong unangia. Ramipedicella longicellularis is identified by generally smooth crusts, absence of phaeophycean hairs, plurangia terminated by 1-2 apical sterile cells, and smaller mostly oblanceolate unangia.