Effects of seasonal growth rate on morphological variation of Undaria pinnatifida (Alariaceae, Phaeophyceae)
Stuart, MD and Hurd, CL and Brown, MT, Effects of seasonal growth rate on morphological variation of Undaria pinnatifida (Alariaceae, Phaeophyceae), Hydrobiologia, 398-399 pp. 191-199. ISSN 0018-8158 (1999) [Refereed Article]
Undaria pinnatifida (Harvey) Suringar is currently divided into two morphological forms, f. typica Yendo. and f.
distans Miyabe & Okamura. The objective of this study was to determine the effects of seasonal variation in growth
rate on the morphology of U. pinnatifida, and to define the form of U. pinnatifida growing in Otago Harbour, New
Zealand. Morphological variables (stipe length, blade length, blade width, sporophyll length and degree of blade
incision), growth rates (frond, blade and stipe) and blade erosion were measured each month from August 1993 to
February 1995, and compared using correspondence analysis. Variation in the morphology of U. pinnatifida was
largely accounted for by varying growth rates. Definition of the form of U. pinnatifida growing in Otago Harbour
is equivocal because morphological characteristics of both f. typica and f. distans were exhibited at different times
of the year.