Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 a...Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 and LAMB010601） were isolated from the two areas in 2009. The morphological characteristics and molecular phylogeny of two strains are compared on the basis of observation of a light microscope, a scanning electron microscope （SEM）, a laser scanning micro-scope （LSM） and an internal transcribed spacer （ITS） sequence data. The mean cell length of strain LAMB090611 is （14.2 ± 1.8） μm （range 11.1–18.7 μm） and mean width is （10.8 ± 1.5） μm （range 8.2– 14.7 μm）. The mean cell length of strain LAMB010601 is （15.1 ± 1.2） μm （range 12.7–17.9 μm） and the mean width is （11.4 ± 1.1） μm （range 9.1–14.7 μm）, respectively. The two strains are similar in morphological characteristics, including a straight apical groove, distinct ventral pore, sulcal extension, cingulum displacement, two or four irregular shaped chloroplasts within the cell and almost equal sized epicone and hypocone. The large and round nucleus is located at the center or at the hypocone of the cell. The sequence length of the ECS strain LAMB090611 and the German strain LAMB010601 is 640 and 646 bp, respectively. The GC content is 49%. The nucleotide similarity of the two strains is 98.1%. The sequence divergence is 0.003. Both strains are confirmed as Karlo-dinium veneficum （D. Ballantine） J. Larsen and this is the first taxonomic report from China and Germany coastal waters. The population dynamics of this toxic species in the ECS and German coastal waters needs to be investigated in the near future.展开更多
Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured ...Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the ef fects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely P rymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Diff erent lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that,(1) all of the three microalgal species had density and time dependent lethal ef fects on A rtermia nauplii, while P. parvum was the most toxic one and had acute lethal eff ects in 5 h. No such acute lethal eff ects were observed in P. elongata or K. veneficum;(2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator.展开更多
基金The National High-Tech Project of China under contract No.2007AA09Z110Chinese Ecology and Oceanography of Harmful Algal Blooms Project Ⅱ under contract No.2010CB428702+3 种基金the National Science Foundation Project under contract No.41176141Foundation of State Oceanic Administration of China under contract Nos 2009123 and 20100310the Basic Research Fund of the Second Institute of Oceanography,the State Oceanic Administration of China under contract No.SZ0824Joint Project between Germany and China supported by International Bureau of Federal Ministry for Education and Research under contract No.CHN06/009
文摘Harmful algal blooms often occurred in the East China Sea （ECS） and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium （LAMB090611 and LAMB010601） were isolated from the two areas in 2009. The morphological characteristics and molecular phylogeny of two strains are compared on the basis of observation of a light microscope, a scanning electron microscope （SEM）, a laser scanning micro-scope （LSM） and an internal transcribed spacer （ITS） sequence data. The mean cell length of strain LAMB090611 is （14.2 ± 1.8） μm （range 11.1–18.7 μm） and mean width is （10.8 ± 1.5） μm （range 8.2– 14.7 μm）. The mean cell length of strain LAMB010601 is （15.1 ± 1.2） μm （range 12.7–17.9 μm） and the mean width is （11.4 ± 1.1） μm （range 9.1–14.7 μm）, respectively. The two strains are similar in morphological characteristics, including a straight apical groove, distinct ventral pore, sulcal extension, cingulum displacement, two or four irregular shaped chloroplasts within the cell and almost equal sized epicone and hypocone. The large and round nucleus is located at the center or at the hypocone of the cell. The sequence length of the ECS strain LAMB090611 and the German strain LAMB010601 is 640 and 646 bp, respectively. The GC content is 49%. The nucleotide similarity of the two strains is 98.1%. The sequence divergence is 0.003. Both strains are confirmed as Karlo-dinium veneficum （D. Ballantine） J. Larsen and this is the first taxonomic report from China and Germany coastal waters. The population dynamics of this toxic species in the ECS and German coastal waters needs to be investigated in the near future.
基金Supported by the Earmarked Fund for Modern Agro-industry Technology Research System,China(No.CARS-49)the Ningbo Science and Technology Research Projects,China(No.2017C110003)+2 种基金the Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Development Fundthe National 111 Project of Chinathe K.C.Wong Magna Fund of Ningbo University
文摘Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the ef fects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely P rymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Diff erent lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that,(1) all of the three microalgal species had density and time dependent lethal ef fects on A rtermia nauplii, while P. parvum was the most toxic one and had acute lethal eff ects in 5 h. No such acute lethal eff ects were observed in P. elongata or K. veneficum;(2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator.
