To improve the wet tensile strength of calcium alginate gel fibers, the effects of stretching and the diameter of the extrusion nozzle on the wet tensile strength of calcium alginate gel fibers were evaluated. Five kinds of algal sodium alginates [low viscosity types (150-M and 150-G) and high viscosity types (350-M, 350-G, and I-5G)] were used as raw materials for calcium alginate gel fibers. Stretching and extrusion nozzle diameter had significant effects on the wet tensile strength of calcium alginate gel fibers. After stretching the original gel fiber length up to 1.4-fold, the wet tensile strength of gel fibers derived from high viscosity type alginates was increased by up to 1.97-fold～2.12fold of the wet tensile strength of each of the original gel fibers. Furthermore, by stretching the original gel fiber length by up to 1.8-fold, the wet tensile strength of each of the original gel fibers was increased by up to 2.35-fold～2.54-fold. The gel fiber strength was also increased by decreasing the extrusion nozzle diameter. From these results, the stretching treatment appears to be a useful process for improving the wet tensile strength of calcium alginate gel fibers.

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Nemalionopsis tortuosa Yoneda et Yagi is a freshwater red macroalga recorded as a threatened species in Japan. Based on variations of branch length and branching density, 43 samples from nine Japanese populations of N. tortuosa were divided into two groups: one possesses short-branches and are densely branched (two localities), and the other one possesses short to long-branches and are sparsely branched (other localities). The variations of thallus and medulla diameters overlapped among the nine populations. Twenty six samples of N. tortuosa from 17 localities, including samples used in the morphological observations, had only 0-4 bp differences (0-0.35％ divergence) in the plastid encoded rbcL sequences. Four samples of the sparsely branched group and all five samples of the densely branched group had identical sequence (seq-A). The statistical parsimony network tree showed the haplotype seq-A as an early divergent lineage in this species. The two groups from the morphological analysis could not be recognized in the phylogenetic analysis, and we concluded that the two morphological groups belong to one taxon, N. tortuosa. Nemalionopsis tortuosa is one of the most rapid extinction of its population, and emergency protective actions are necessary for this species.

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The inhibitory effect on the activation of hyaluronidase contained in an edible blue-green alga, Nostochopsis sp. (Cyanophyta) was evaluated in this study. The half maximal inhibitory concentrations (IC₅₀) of ethanol-insoluble fractions of aqueous extract from two lots of the alga were 0.0276 mg ml^-1 and 0.0259 mg ml^-1, respectively. The IC₅₀ of disodium cromoglycate (DSCG), usually used as an anti-allergy, was 0.1132 mg ml^-1. The IC₅₀ of the ethanol-insoluble fraction was only about 25％ of that. Thus, some strong anti-allergy substances seem to be included in the aqueous extract of Nostochopsis sp.

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