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Morphology and life history of Coelocladia arctica (Dictyosiphonales, Phaeophyceae), new to Japan *
Author(s) -
Kawai Hiroshi
Publication year - 1997
Publication title -
phycological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.438
H-Index - 44
eISSN - 1440-1835
pISSN - 1322-0829
DOI - 10.1111/j.1440-1835.1997.tb00074.x
Subject(s) - pyrenoid , sporangium , thallus , biology , protonema , botany , chloroplast , spore , moss , biochemistry , gene
SUMMARY The occurrence of Coelocladia arctica Rosenvinge (Dictyosiphonales, Phaeophyceae) is reported for the first time in the Pacific Ocean, from Oshoro, Hokkaido, Japan. The field material was approximately 30 mm in height, up to 300 M‐μn in diameter, 2‐3 times irregularly branched and provided with phaeophycean hairs and plurilocular sporangia. The thallus was composed of several (usually four) large, hyaline, rounded, isodiametric inner cells, with smaller sub‐cortical and pigmented cortical cells. The plurilocular sporangia were 3‐4 celled, often branched, and protruded from the cortical cells, arranged in a crown‐shaped complex. In culture, the plurispores germinated unipolarly leaving an emptied original spore wall, and developed into a branched protonema. Cells of the protonema as well as the erect thallus contained several disc‐shaped chloroplasts with pyrenoids. Uniseriate erect filaments arose from the protonema, then became polystichous and formed branches. Unilocular sporangia were never observed in the field or in cultured material. Erect thalli were formed under culture conditions of 5‐15°C, and developed a thick parenchyma at 5‐10°C, irrespective of the day length.