Morphological variability of Undaria pinnatifida (Harvey) Suringar, 1873 (Phaeophyceae, Laminariales) in Peter the Great Bay, Sea of Japan

The morphological variability of the brown alga Undaria pinnatifida was studied in Peter the Great Bay (Sea of Japan). Comparison of the morphology of algae growing at eight sites of the bay that have different water movement revealed three phenotypically different population groups. A discriminant analysis of a set of morphological traits demonstrated that the width of the undivided part of the lamina and the stipe length make the most significant contribution to the discrimination of the detected groups. Analysis of the environmental dependence of morphological traits showed that lamina width and width of undivided part of lamina depend generally on water movement intensity, whereas the stipe length and thallus length are influenced by light intensity and surf degree.