【摘要】 甲藻环沟藻属于一类无色素体、表面有脊的裸甲藻,因可捕食一些重要的赤潮生物而在海洋生态系统中扮演着重要的角色。有关中国近海环沟藻属的物种多样性信息非常有限。本文报道了2个新记录种——纺锤环沟藻(Gyrodinium fusiforme)和莫氏环沟藻(G.moestrupii)。纺锤环沟藻细胞呈纺锤形,长48.0–58.0μm,宽18.0–23.0μm,长宽比为2.4–3.0,和模式种相比体型和长宽比都较小。莫氏环沟藻细胞也呈纺锤形,长约30μm,宽约15μm。我们测定了纺锤环沟藻和莫氏环沟藻大亚基的部分序列,并根据大亚基序列利用最大似然法和贝叶斯法建立了系统发育树。结果显示环沟藻属是单源的,纺锤环沟藻和裂缝环沟藻(G.fissum)聚合在一起,但是与螺旋环沟藻(G.spirale)分离。纺锤环沟藻和莫氏环沟藻分别可以摄食米氏凯伦藻(Karenia mikimotoi)和具齿原甲藻(Prorocentrum dentatum),前者在米氏凯伦藻赤潮中的大量出现显示它可以促进赤潮的消退。更多还原

【Abstract】 The athecate dinoflagellate genus Gyrodinium includes heterotrophic species that prey on other dinoflagellates,and thus play an important role in marine ecology.Information about the Gyrodinium diversity along the coast of China is limited.Here we report on the characteristics of two species,Gyrodinium fusiforme Kofoid & Swezy and Gyrodinium moestrupii Yoon,Kang,and Jeong that were isolated from a Karenia mikimotoi bloom sample in the East China Sea.The cells of G.fusiforme were fusiform with a length of 48.0–58.0 μm and a width of 18.0–23.0 μm.Cells of G.moestrupii were also fusiform and approximately 30 μm long and 15 μm wide.Partial large subunit(LSU) ribosomal DNA sequences were obtained from single cells of G.fusiforme and G.moestrupii and phylogenetic trees were built using maximum likelihood(ML) and Bayesian inference(BI).In the phylogenetic trees the genus Gyrodinium is monophyletic,and G.fusiforme groups together with G.fissum,but separates from G.spirale although they are similar in morphology.G.fusiforme and G.moestrupii can prey on Karenia mikimotoii and Prorocentrum dentatum respectively.The high abundance of G.fusiforme during K.mikimotoi bloom suggests it may play a role in bloom decline.更多还原