Cladosiphon Okamuranus Research Articles

オキナワモズクの養殖に関する研究-III

In this paper, the morphogenesis of zoospore derived from plurilocular sporangium produced on the thallus of Cladosiphon okamuranus, as well as the influence of water temperature, salinity and illumination on the growth of its germlings were examined in the laboratory.1) The development of most zoospores from plurilocular sporangia showed the discoid type. The discoid germlings derived newly formed plurilocular sporangia and developed into the thalli of sporophyte. However, when the discoid germlings were cultured at a higher temperature (25°C ), there were no growth of the erect germlings; showing only repeated generations of discoid development by the zoospores from their plurilocular sporangia.2) Suitable culture conditions for the attachment of zoospores from plurilocular sporangia in the laboratory were 20-25°C in water temperature, nearly 31‰ in salinity and 1-2.5klx in illuminance.3) As regards the adequate culture conditions for the growth of germlings before reaching 1 mm in height, the water temperature was 25-30°C, but when they began to develop into erect germlings, best growth occurred between 15-20°C, the adequate conditions being 15-45‰ salinity and 5-10klx illuminance.

Ultrastructure of sporophyte of <i>Cladosiphon okamuranus</i> Tokida (Ectocarpales, Phaeophyceae)

Transmission Electron Microscopy of 35 day old culture of Cladosiphon okamuranus Tokida, revealed several chloroplasts and other organelles in each cell of assimilatory filaments. Each chloroplast possesses single pyrenoid and Lipid bodies while in hair cells, there were few chloroplasts clinging to plasma-membrane and many pathholes were seen in the cell wall. Key words: Cladosiphon okamuranus; Brown algae; Ultrastructure; Pathhole DOI: 10.3329/bjb.v38i2.5143 Bangladesh J. Bot. 38(2): 177-180, 2009 (December)

Plurispore development of <i>Cladosiphon okamuranus</i> Tokida (Chordariaceae, Phaeophyta)

Development of plurispores and effects of temperature on their attachment to substrata were studied using mature plurilocular sporangia of Cladosiphon okamuranus Tokida. Development of plurispore showed the disc type, a large number of assimilatory filaments were found to develop from the middle or central part of a disc. These compact and parallel assimilatory filaments formed pseudoparenchyma (multiaxial) with abundant lateral branches. The attachment and development of a plurispore were affected significantly by temperature. Suitable seeding temperature was found to be 17-26º and 26° being optimum for successful attachment. At a temperature over 26ºC, the plurispore could not attach tightly to a substratum or developed poorly.   Key words: Plurispores, Cladosiphon okamuranus, Multiaxial, Hair, Pseudoparenchyma DOI = 10.3329/bjb.v36i2.1505  Bangladesh J. Bot. 36(2): 157-162, 2007 (December)