FIVE RED TIDE SPECIES IN GENUS PROROCENTRUM INCLUDING THE DESCRIPTION OF PROROCENTRUM DONGHAIENSE LU SP. NOV.FROM THE EAST CHINA SEA

A new planktonic dinoflagellate, Prorocentrum donghaiense Lu sp. nov., is described in the present paper. The water sample was collected from the Changjiang Estuary, the East China Sea. The species identification is based on shape, size, surface micro morphology, ornamentation of thecal plates and the architecture of the periflagellar area and the intercalary bands as seen by light and scanning electron microscope. Prorocentrum donghaiense Lu sp. nov. is compared with other prorocentrum species with respect to morphological characteristics and bloom behavior. It is not known whether Prorocentrum donghaiense Lu sp. nov produces phycotoxins like some other Prorocentrum species. Four other red tide species in the family Prorocentraceae (Dinophyceae), namely P. balticum , P. minimum, P. micans, P. triestinum , were examined and identified by light and scanning electron microscope. They have been recorded as bloom forming species. Some aggregates of Prorocentrum are observed at the end of blooms. An event of strong discoloration caused by P. donghaiense could be detected by satellite sensor in the East China Sea in the late spring of 1995.

Integrating a DNA barcoding project with an ecological survey:a case study on temperate intertidal polychaete communities in Qingdao,China

In this study,we integrated a DNA barcoding project with an ecological survey on intertidal polychaete communities and investigated the utility of CO1 gene sequence as a DNA barcode for the classification of the intertidal polychaetes.Using 16S rDNA as a complementary marker and combining morphological and ecological characterization,some of dominant and common polychaete species from Chinese coasts were assessed for their taxonomic status.We obtained 22 haplotype gene sequences of 13 taxa,including 10 CO1 sequences and 12 16S rDNA sequences.Based on intra-and inter-specific distances,we built phylogenetic trees using the neighbor-joining method.Our study suggested that the mitochondrial CO1 gene was a valid DNA barcoding marker for species identification in polychaetes,but other genes,such as 16S rDNA,could be used as a complementary genetic marker.For more accurate species identification and effective testing of species hypothesis,DNA barcoding should be incorporated with morphological,ecological,biogeographical,and phylogenetic information.The application of DNA barcoding and molecular identification in the ecological survey on the intertidal polychaete communities demonstrated the feasibility of integrating DNA taxonomy and ecology.

Effect of nitrogen to phosphorus ratios on cell proliferation in marine micro algae

The ratio of nitrogen/phosphorus （N/P） is known to affect cell proliferation of some marine micro algae. We evaluated the effect of N/P ratios on the proliferation and succession of phytoplankton using five marine micro algae species. We used two sources of nitrogen, NH4Cl （N1） and urea （N2）, and a single source of phosphorous, NaH2PO4（P）. The optimal N/P ratio that differed among the five species was affected by the source of nitrogen, being as follows （N1/P, N2/P in order）： Thalassiosira sp. （30/1, 20/1）, Heterosigma akashiwo （30/1, 30/1）, Chroornonas salina （20/1, 30/1）, Chaetoceros gracilis （40/1, 60/1）, and A lexandrium sp. （10/1, 30/1）. Thus, the source of nitrogen must be considered when analyzing the N/P ratio. Our results provide insight for predicting phytoplankton succession in coastal waters and may be used to forecast the potential risk of harmful algal blooms.