大连湾赤潮生物──赤潮异弯藻

STUDIES ON HETEROSIGMA AKASHIWO (HADA) HADA IN THE DALIAN BIGHT, LIAONING, CHINA

于1985，1986和1987三年的夏季在辽宁省大连湾采集赤潮生物──赤潮异湾藻，以相差显微镜和扫描电镜进行了形态观察和分类研究；同时述及其分类沿革及至今仍存在的争议，结合本种在大连湾的生态特点简要地综述了其在世界上的分布、生理宗、昼夜垂直移动、营养摄取以及细胞分裂周期和种群繁殖等。结果表明，在温带近海夏、秋季赤潮异弯藻的生长率最高，冬季休眠于海底；温度是限制其复苏的主要因子。本种昼夜都能摄取营养，生态效益较高是其易于形成赤潮的动力。海水中的N，Fe和Mn的含量是影响本种赤潮发生的营养因子。

In the summers (June-August) of 1985, 1986 and 1987, a large in scale brownishred bloom of Heterotigma akaskiwo (Hada) Hadala species newly recorded fromChina Seas appeared and lasted for about 7 days respectively in the Dalian Bight.This paper discusses the morphology, classification, recent controversy on the systematic taxonomy of the H. akashiwo (Hada) Hada, ecologic characteristics, and theenvironmental factors (nutrients, temperature, salinity, etc.) that directly or indirectly came red tide of this species here.In the temperate neritic region, the H. akaskiwo (Hada) Hada lie dorment inthe sea bottom mud during the winter, when the temperature of the bottom seawaterincreases over 15℃ (the surface water in the Dalian Bight is about 22℃ and 25-29in salinity), it revives and reachs the highest growth rate from summer to autumn,so the temperature is the main limiting factor for the revival of H. akashiwo, itcould take up the nutrients containing in the seawater from the day-time to night,so the red tide of H. akashiwo appears more often than that of the algae which onlyabsorb the nutrients in the day-time, uch as the diatoms. In the seawater of theDalian Bight, the contents of N, Fe, and Mn are the nutrient factors affecting theoccurrence of red tide of H. akaskiwo (Hada) Hada.