Optimum growth of Gracilaria (verrucosa type) in British Columbia occurred between 5 and 6 meters below mean tide level and correlated with solar radiation throughout the season. Vegetative populations declined with a consequent increase in reproductive forms to a maximum in July. Tetrasporophytes dominated the reproductive population and in July attained the greatest seasonal biomass of all forms of the alga. Maximum population and biomass were attained by carposoporophytes in July and by male gametophytes one month earlier. An inverse relationship between biomass and yield of agar was apparent only for the vegetative and tetrasporic forms of the alga. Variations in yields, gel strengths, and gelation characteristics of the agars isolated, were demonstrated to be dependent on time of season and life stages of the alga. Ranked in the following decreasing order of merit as a source of agar were the cystocarpic, tetrasporic, vegetative and male gametophytic forms of Gracilaria (verrucosa type).

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Biochemical composition of body segments and physiological condition of the spot prawn (Pandalus platyceros) were determined during 84 d of starvation and 21 d of subsequent feeding. Maximum molting frequency, 1.79%∙d−1, occurred from day 22 to 43 and mortalities peaked at 0.81%∙d−1 on resumption of feeding. Ratios of wet weight of hepatopancreas to abdomen or whole body decreased on starvation and increased on feeding, and so provided an index of physiological condition. Uptake of moisture and chlorides with loss of other halides in prawn tissue resulted from starvation. Resting oxygen consumption rate declined by 50% after 40 d of starvation. Lipid in the hepatopancreas increased during early inanition to become the major energy source. Lipid contributed 73.1%, protein 20.6%, and carbohydrate 6.3% of total metabolized reserves. Hepatopancreas, carcass, and abdominal muscle generated 49.1, 33.4, and 17.5% of energy utilized. On subsequent feeding, lipid, carbohydrate, and protein accounted for 73.8, 20.1, and 6.1% of total caloric uptake with energy assimilation by body sections similar to depletion values. Spot prawn have sufficient reserves to remain in good commercial condition for 40 d without food.

The cell-wall polysaccharide from R. pertusa has been shown, by g.l.c, mass spectrum, and p.m.r. studies on the methylated derivative, to consist of β-(1 → 4)-linked-D-glucopyranose residues. The assessment of anomeric configuration in polysaccharides by p.m.r. spectroscopy is illustrated by the spectra of methylated amylose and cellulose. The preparation of anilides for mass spectral analysis of sugars is suggested.