Culture of brown alga Laminaria japonica (Phaeophyta, Laminariales) in warm waters of Shikoku, Japan

Abstract

55-60Young sporophytes of biennial L. japonica from cold waters of Hokkaido were transplanted into warm waters of Uranouchi inlet, Shikoku island. Sporelings were grown at different depths below the surface of the sea. Healthy growth of the plants was obtained from December to May at 10-degrees to 23-degrees-C. Maximum values of plant length of 254.5 cm, blade length 25 1.1 cm, breadth 15.6 cm, wet weight 290.7 g and dry weight 44.5 g were obtained at 1.5 to 2 m depth in May 1984. Maximum substantiality (utility) value (91.23 mg.cm-2) was obtained in 1986. Nearly 8.7 kg wet weight m-1 length of the rope was obtained. Maximum growth rate per day was 10 and 4% for length and fresh weight respectively in January, 2% for breadth in April and 5.5% for dry weight in May. Linear growth rate of transition region was maximum, 13.8% d-1 in March. Plants started fruiting in February and many zoospores were liberated in April-May. The zoospores developed into many gametophytes at 17-degrees-C in incubators