Growth and Maturation of Sargassum macrocarpum C. Agardh in Fukawa Bay, the Sea of Japan

Abstract

Growth and maturation of Sargassum macrocarpum C. Agardh were studied in Fukawa Bay facing to the Sea of Japan, Yamaguchi Prefecture, at the depth of 8 m, from June 1993 to July 1994. New main branches on perennial stem had been apparently observed in June, and grew increasingly through July to March in the next year, then reached the maximum length and dry weight of the branches in March and May, respectively. Thalli with three or more growth rings in holdfast matured and formed receptacles through March to June. The release of oospores and embryos was observed only in June. The number of main branches was almost the same among adult thalli and did not show variation throughout the year. The minimum and maximum standing crops were 257.6gm^-2 in August 1993 and 1155.7gm^-2 in May 1994, respectively.