Contrasting temperature chracteristics of Laminaria digitata and Hedophyllum nigripes - C:N-ratio, growth rate, PAM fluorometry, gametogenesis

We investigated effects of temperature on gametophytes and sporophytes of the two morphologically similar kelp species Laminaria digitata and Hedophyllum nigripes co-occurring in the Arctic. We quantified gametogenesis, sporophyte recruitment and growth, optimal quantum yield and carbon and nitrogen content of sporophytes, as well as survival of both life cycle stages along temperature gradients (0-25°C), using several unialgal strains isolated from the European Arctic in Kongsfjorden, western Spitsbergen.