摘要
海洋生物区系是各海区的地理环境、水文状况和这些环境条件的历史发展情况对生物自然分布综合影响的反映。为探讨海洋生物自然分布的演变过程及规律,近年来海洋生物区系的研究日益受到重视。角毛藻属包括从寒带到热带的各种生态性质的种类,在太平洋西部浅海区本属的出现种数居浮游硅藻之冠,也是黄海浮游硅藻区系组成的最重要成分。角毛藻属在海洋上层水中营浮游生活,生命周期很短,其分布可随水文条件的变化而迅速改观。因此,研究角毛藻属区系时,除考虑种类和地理分布外,还要结合其生态反映一并分析。而这样综合性的报告至今还很少见。本文旨在从此三方面,对黄海角毛藻属区系的性质及与邻近区系间的亲疏关系进行初步探讨。
(1)The Chaetoceros flora of the Yellow Sea is mainly temperate in nature,comprising of 38 species,of which 21 are temperate species and 12 are tropical species.The ecological nature of the remaining species is not known.The temperate species may be subdivided into warm-temperate species(15-25℃)and cold-temperate species(5-15℃).There is considerable variation in the hydrographic conditions of the Yellow Sea.The annual temperature varies from<0-6℃in winter,24-28℃in summer.With the exception of the southeastern part which is under the influence of the western branch of the Tsushima Current,a great part of the Yellow Sea is away from the influence of warm or cold currents.Due to the difference in the ability of different Chaetoceros species to tolerate changes in temperature and salinity conditions,there is an obvious seasonal succession of species.Warm-temperate species,such as Ch.affinis Lauder,Ch.elbenii Grunow and Ch.castracanei Karsten etc.(see Table 1),which are more abundant,have their flowering period in late spring and early fall,being rare in midsummer.They are more abundant in the Yellow Sea than in the East China Sea.In the South China Sea they are much less abundant.Ch.socialis Lauder,Ch.subsecun-dus(Grunow)Hustedt and Ch.densus Cleve etc.,are cold-temperate species,being more abundant in colder waters.The first 2 species flourish in winter and the last one in late autumn to early spring.The Yellow Sea is the southern boundary of their distribution.During summer and early autumn,when temperature is highest(above 25℃),tropical species occurred,but with no apparent bloom.All the warm-water species,with the exception of Ch.lorenzianus Grunow,Ch.paradoxum Cleve,Ch.pseudocurvisetus Mangin and Ch.siamense Ostenfeld which occur throughout the Yellow Sea,occur in the south-eastern part(to the south of 35°N and east of 124°E)of the Yellow Sea,which is slightly affected by the Tsushima Current.(2)According to Aikawa(1934,1936),the plankton compositions around Santo-kaku(山东省成山角)and Syosei-to(朝鲜小青岛)where there is an upwelling current,much resembles that of the Kuroshio-water.The results of our investigation do not bear out his findings.Although a few tropical species,such as Ch.denticulatum Lauder and Ch.diversus Gleve occasionally do occur in Santo-kaku,their number is negligible.We consider it possible that they were transported by prevailing wind-moved surface water to the northwest.(3)The Yellow Sea Chaetoceros flora is similar to that of Pohai although it is richer in species.Compared with that of the western part of the East China Sea,it is even much closer,although many tropical species found in the latter are absent in the former.As is expected,it differs greatly from that of the South China Sea(see Table 3).The number of Chaetoceros species of the Yellow Sea which is in common with that of Japan Sea is more than in other areas of the Western Pacific.As the Chaetoceros flora of Wakasa Bay(若狭湾near 35°40’N 135°30’E)which is under the influence of the Tsushima Current is warmer and that of the Takashima(高岛near 43°N 143°E)is colder than that of the Yellow Sea,we may infer that the Chaetoceros flora of the region between these two localities is most related to that of the Yellow Sea.(4)Based on the temperature range at which different species of Chaetocerosflourish,they may be divided into the following groups:arctic species--<0-5℃,coldtemperate species--5-15℃,warm temperate species--15-25℃,and tropical species--above 25℃.Due to the continuous movement of the water,the planktonic habitand stronger hardiness of neritic species,adventitious individuals of Chaetoceros often may be found in places far from their original habitat.Therefore when studing the Chaetoceros flora we must also take into account currents and seasonal variation in quantity of these algae other than water temperature alone.
作者
郭玉潔
Y.C.KUO(Institute of Oceanology,Academia Sinica)
出处
《海洋与湖沼》
1963年第4期322-332,共11页
Oceanologia Et Limnologia Sinica
