A culture study of Caulacanthus ustulatus (Caulacanthaceae, Gigartinales, Rhodophyta) from Europe and Asia
Rueness, J. (1997). A culture study of Caulacanthus ustulatus (Caulacanthaceae, Gigartinales, Rhodophyta) from Europe and Asia. Cryptogam., Algol. 18(2): 175-185
In: Cryptogamie. Algologie. ADAC: Paris. ISSN 0181-1568; e-ISSN 1776-0984, more
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| Abstract |
Caulacanthus ustulatus (Turner) Kutzing was collected near Roscoff on the north coast of western Brittany and isolated into unialgal culture. The species is a recent introduction in this area, and the nearest known locality before 1986 was Biarritz. Two other Caulacanthus isolates were studied in culture and compared with the Roscoff isolate. One came from Gibraltar, not far from the type locality (Cadiz), and the other was from Qingdao, China, where the alga is passing under the name C. okamurae Yamada. The three isolates were morphologically similar, and thus supporting the recent proposal of reducing C. okamurae to synonymy with C. ustulatus. The isolate from China remained vegetative in culture, while the European isolates produced tetrasporangia. Germination of tetraspores and mature male and female plants are described for the Roscoff isolate. Only one carposporophyte was produced, and the germination of carpospores is described. Vegetative growth was measured on a temperature gradient growth table. Very little growth took place at 6 degrees C. Growth was best at ca. 17 degrees C, and slightly reduced at 13 degrees C and 26 degrees C. |
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