Furcellaria

Abstract: Followed by the massive increase in the biomass of Pilayella littoralis, Fucus vesiculosus has almost disappeared in Koiguste Bay, north-eastern Baltic Sea during 1995‐1998. Consequently, Idotea baltica, which previously fed on Fucus, switched to new food items ‐ Furcellaria lumbricalis and Pilayella littoralis. Idotea grazed more Pilayella than Furcellaria whereas Furcellaria was highly preferred as a habitat. Maximum 2.2% and 4.7% of the production of Furcellaria and Pilayella were removed by grazing. We conclude that the grazing pressure by Idotea is not sufficient to control the outbreak of Pilayella. However, Idotea has an advantageous effect on the persistence of Furcellaria by preferentially removing fast growing epiphyte Pilayella.

Abstract: Callus formation of seven species of the agarophyte marine algae Phyllophora nervosa, Gracilaria verrucosa, Furcellaria fastigiata, ceramium kondoi, Gelidium vagum, Laurencia paniculata, Rhodymenia pertusa was obtained from 1984 to 1986. A new sterile agent, chlorhexidin bigluconate, was used to get axenic explants from the algae thalli. The formation of callus from axenic explants depended on temperature of cultivation. In the case of F. fastigiata and G. vagum it occurred at 12° to 20°C, and with P. nervosa at 18° to 26°C. The exchange of sucrose with mannitol in the culture medium and the addition of some growth regulators stimulated the formation of callus. Mass formation of lumpy and warty extensions was observed in the explants from leaf blades of P. nervosa. The results might be useful for improving the aquaculture of agarophyte marine algae.

Abstract: Aqueous extracts from 30 species of red algae were treated with κ-carrageenase, a specific hydrolase for κ-carrageenin. The total reducing power of the hydrolyzate indicated that the algae could be divided into three groups on the basis of the content of κ-carrageenin. Group 1 included Gigartina acicularis, G. radula, G. pistillata, G. christata, and Iridaea sp. with a low value. Group 2 included Chondrus crispus, G. stellata, G. stiriata, Rhodoglossum affine, Furcellaria fastigiata, and Endocladia muricata, all with values comparable with that in C. crispus. Group 3 included Hypnea musciformis and a Yatabella sp. with a value greater than that for C. crispus. The occurrence of agarose and of κ-carrageenin in the Rhodophyceae is discussed as a factor in their taxonomy.

Abstract: Addition of potassium chloride to an aqueous extract of the red alga Furcellariafastigiata precipitated a polysaccharide containing residues of D-galactose and 3,6-anhydro-D-galactose in the approx...