Seasonal Growth and Maturation of Hypnea japonica (Gigartinales, Rhodophyta) along the Coast of Sokodo in Hachijo-jima Island, Central Japan

概要

論文の詳細を見る
Seasonal growth and maturation in populations of Hypnea japonica was studied between January 2006 and December 2009. The algae population was located at depths of 1-3 m below sea level along the coast of Hachijo-jima Island off central Japan where H. japonica started growing in December. Mean wet weight of this species showed a seasonal peak between April and June; however, it decreased between August and September. Reproductive plants were found between June and July, where tetrasporic plants were predominant over cystocarpic plants. Tetrasporic plants prevailed when water temperatures rose, suggesting that rise in seawater temperature may influence tetrasporogenesis of H. japonica in Hachijo-jima Island. A significant positive correlation was observed between the mean wet weight and NH3-N concentration (r=0.54, P < 0.05) and PO4-P concentration (r=0.59, P < 0.05). Nutrients supplied by a meander of the Kuroshio current were vital for a high growth rate of H. japonica in Hachijo-jima Island.
日本水産増殖学会の論文