Distribution of indicator dinoflagellates in the East China Sea

The material discussed in this paper is from four cruises which were carried out in May-June,1986 (spring),July -August,1987(summer).October -November,1988(autumn)and December,1987(winter)respectively.Identified dinoflagellates were 141 species (including varieties and forms) belonging to 18 genera.
According to the distribution and ecological L11characteristics of dinoflagellates species,we can divide them into three groups:1) Hyporhaline-neritic group:they are distributed only in type Ⅲ and type Ⅳ water and they perform an evident function indicating continental coast water; 2) Eurythermic-euryhaline group represented by Protoperidinium depressum,Gentium fusus,etc.They are fond of perching in mixing water which character is similar to that of coast water even though they are distributed in different water systems; 3) Hyperthermic-hyperhaline group:on the basis of varying degrees to which they tolerate temperature and salinity,we can divide them into two sub-groups:euryhyperthermic-euryhyperhaline subgroup and stenohyperthermic-stenohyperhaline subgroup.The first subgroup is represented by Pyrocystns pseudoaoctiluca whose adaptability reation occurred with the changing of hydrographic environment.The second subgroup is tropic oceanic species which can serve as a good indicator for Kuroshio in the East China Sea.Its biological boundary soinsides well with the hydrographic boundary of Kuroshio water.