摘要
哲水蚤(Calanus)为我国近海浮游桡足类中的优势种,不但数量多、分布广,并且个体也较大;在探讨我国海洋浮游生物数量变动时,必须重视这种桡足类的生态学研究。过去,有不少学者在桡足类的个体生态学方面做过很多工作,特别是对飞马哲水蚤[Calanus finmarchicus(Gunn.)]的研究最为详尽(Marshall & Orr 1955)。这些研究不论在理谕上或生产实践上都具有重要意义。在我国海洋浮游生物学文献中,到目前还未见到有关桡足类的个体生态学的研究论文。本文对中华哲水蚤(Calanus sinicus Brodsky)的繁殖、性比率和体长的季节变化等问题进行初步研究,作为对这种桡足类个体生态学研究的开端。
In this paper the results of a study of the morphology of Calanus sinlcus Brodsky collected in our coastal waters from the Gulf of Pohai to the South China Sea and of a comparison of it with the closely-related Calanus pacificus Brodsky of adjacent seas are presented.This species is most abundantly distributed in the Yellow Sea and in the coastal waters of the East China Sea.In offshore waters of the South China Sea,and in the offshore waters off Chekiang under the influence of the Taiwan warm current,it is rarely found.Judging from its geographical distribution,it can be considered as a warm-temperate species.From the seasonal variation in abundance of individuals in different developmental stages,it is possible to divide them into two breeding types.In the Gulf of Pohai,the Yellow Sea and the East China Sea,it has three breeding periods-in March-May,in June-August and in October-November.Thus the generation produced in each period may be termed the spring,the summer,and the autumn generation respectively.The number of individuals produced is most abundant in spring and in autumn.In the South China Sea,only one breeding period is apparent-in early spring.The ratio of female to male in stage V copepodites is about 1:1,but for adult individuals,it is greater.It is possible that the period between stage V to maturity is a critical period for male copepodites,many of them probably dying before reaching maturity but it may also be possible that the life span of the adult male is shorter.There is also seasonal variation in sex ratio of adults,but in the whole year female individuals make up the greater part of the total population.There is a marked difference in size of adult individuals during different seasons in one and the same region and in different regions.This difference is largely related,inter alia to changes in temperature conditions.The relationship is an inverse one in which body size decreases with increase in temperature.Thus in the Gulf of Pohai and in the northern Yellow Sea the mean size of individuals--3.2 mm--is recorded in winter when the temperature of the water is between 3-7℃.In late spring,at 15-18℃,it is 2.9 mm,and in early summer,at 20-22℃,it is 2.7 mm.From north to south,a marked decrease in size of adult individuals is also noted.
作者
陈清潮
CHEN QING-CHAO(Institute of Oceanology,Academia Sinica)
出处
《海洋与湖沼》
1964年第3期272-288,共17页
Oceanologia Et Limnologia Sinica
