中国四个河口潮间带甲藻孢囊多样性研究

2014—2016年, 为调查研究中国大辽河、涧河、闽江与九龙江河口潮间带表层沉积物中甲藻孢囊多样性, 开展了4个季度表层沉积物样品采集, 通过多钨酸钠法提取甲藻孢囊后进行鉴定, 共鉴定出43种(隶属16属)和5种未定种, 包括自养型17种和异养型26种。其中孟迪原多甲藻(Protoperidinium mendiolae), 脆弱海胆藻(Echinidinium delicatum)和透明海胆藻(E. transparantum)为我国沿海未报道的新记录种类。调查中发现了一种产麻痹性贝毒的塔玛亚历山大藻复合体(Alexandrium tamarense complex), 以及3种产虾夷扇贝毒素的甲藻孢囊, 分别为网纹原角藻(Protoceratium reticulatum), 多边舌甲藻(Lingulodinium polyedrum)和具刺膝沟藻(Gonyaulax spinifera)。甲藻孢囊丰度在4个河口的分布具有明显差异。大辽河口孢囊丰度最高, 变化范围为47~94 cysts/g DW(干质量); 其次为涧河口, 孢囊丰度变化范围为24~75 cysts/g DW; 闽江口与九龙江口孢囊丰度相对较低, 变化范围分别为14~50 cysts/g DW与5~50 cysts/g DW。与沉积物环境因素的相关性分析表明, 自养型孢囊丰度和孢囊总丰度均与河口盐度、间隙水总溶解态氮营养盐浓度、溶解无机氮浓度、氨氮浓度呈显著正相关关系; 多样性指数与盐度、沉积物粒度(<63 μm)呈显著正相关关系。该研究对于了解我国河口潮间带甲藻孢囊多样性以及形成机制具有重要参考价值。     

氮形态组成对海洋浮游植物群落结构的影响与动力学研究

海洋浮游植物群落结构的改变与营养盐结构有关,不同形态氮可能会影响优势种生长从而改变浮游植物群落结构.本文针对莱州湾硅藻向甲藻潜在的种群演替问题,通过船基围隔生态系现场氮加富培养实验,研究NO3-N、NH4-N、陆源有机氮(DONts)和藻源有机氮(DONss)对海洋浮游植物群落结构的影响.结果表明,在NO3-N、NH4...     

Palynological evidence for climatic and oceanic variability off NW Africa during the late Holocene

Pollen and organic-walled dinoflagellate cyst assemblages from core GeoB 9503-5 retrieved from the mud-belt ( 50 m water depth) off the Senegal River mouth have been analyzed to reconstruct short-term palaeoceanographic and palaeoenvironmental changes in subtropical NW Africa during the time interval from ca. 4200 to 1200 cal yr BP. Our study emphasizes significant coeval changes in continental and oceanic environments in and off Senegal and shows that initial dry conditions were followed by a strong and rapid increase in humidity between ca. 2900 and 2500 cal yr BP. After ca. 2500 cal yr BP, the environment slowly became drier again as indicated by slight increases in Sahelian savannah and desert elements in the pollen record. Around ca. 2200 cal yr BP, this relatively dry period ended with periodic pulses of high terrigenous contributions and strong fluctuations in fern spore and river plume dinoflagellate cyst percentages as well as in the fluxes of pollen, dinoflagellate cysts, fresh-water algae and plant cuticles, suggesting “episodic flash flood” events of the Senegal River. The driest phase developed after about 2100 cal yr BP.     

A preliminary investigation into calcareous dinoflagellate cysts and problematic microfossils from an expanded Cretaceous/Paleogene boundary section at Kulstirenden, Stevns Klint, Denmark

Located to the north of the Stevns Klint Peninsula (Denmark), Kulstirenden shows the transition from Cretaceous chalks to Danian carbonates across the Cretaceous - Paleogene (K/Pg) boundary. The K/Pg boundary at Kulstirenden is represented by the Fiskeler Member (Fish Clay), a streaked marl interval with a smectite rich, red oxidised layer at its base marking the boundary. The Fiskeler Member is important as it includes the iridium concentration linked to the bolide impact which may have caused the end-Cretaceous mass extinction and is at its maximum thickness at Kulstirenden (c.45 cm). Calcareous dinoflagellate cysts (Calciodinelloideae) have been investigated from within the fine fraction (45-125 μm) at Kulstirenden in order to understand the ecological implications of these enigmatic microfossils. Several species were found within the Fiskeler Member, including Orthopithonella collarisWendler et al. (2001, Rev. Palaeobot. Palynol. 115, 69-77). This species is of particular interest as it demonstrates reduced paratabulation and may indicate a transgressive period immediately after the K/Pg boundary event. O. collaris has been described as a morphotype formed under post-K/Pg environmental conditions and is, therefore, described as a “disaster” taxon that marks the K/Pg boundary at Stevns Klint. The distribution of this taxon is more extensive than previously documented, disappearing as carbonate sedimentation returned in the Cerithium Limestone Member of the Danian. Several calcareous microfossil specimens that were found cannot be associated with the dinoflagellates and display Bolboforma-like features. While the origins of Bolboforma are enigmatic, the current finding expands their stratigraphic range and suggests an appearance of this group of organisms found at Stevns Klint may give an insight into the inception of this group into the earliest Danian.     

Acute Toxicity of Formalin to the Red-tide Dinoflageilate Prorocentrum minimum Schiller （Protozoa, Mastigophora）

The acute toxic levels of formalin to a marine red-tide dinoflagellate Prorocentrum minimum Schiller (Mastigophora, Dinoflagellida) were determined by linear regression analysis. The data obtained revealed that there is a close regression relationship between logarithmic concentrations of formalin and mortality probit scales of the organism when exposure times are 1, 2, 6, 12, 24 h. The median lethal concentrations (LC50 values) obtained from correlation analysis for these exposure times (with 95% confidence intervals), were 11.83, 6.76, 4.37, 4.27 and 3.98mgL^-1 respectively. A toxicity curve was obtained to connect the exposure time and LC50 value from the correlation between them. The results indicated that P. minimum could be killed or fixed by formalin in the concentration range of 4-12mgL^-1 within 1-24h.     

A late eocene-early Oligocene transgressive event in the Golfo San Jorge basin: Palynological results and stratigraphic implications

A new Cenozoic dataset in the subsurface of the South Flank of the Golfo San Jorge Basin (Santa Cruz province) allowed to identify a non-previously recognized transgressive event of late Eocene to early Oligocene age. Below of a marine succession containing a dinoflagellate cyst assemblage that characterizes the C/G palynological zone of the Chenque Formation (early Miocene), a 80–110 m thick marine succession contains a palynological assemblage integrated by Gelatia inflata, Diphyes colligerum and Reticulatosphaera actinocoronata supporting the occurrence of a marine incursion in the basin during the Eocene–Oligocene transition (EOT). The new lithostratigraphic unit - here defined as El Huemul Formation – covers in sharp contact to the Sarmiento Formation, and become thinner from East to West; the unit has been identified in about 1800 well logs covering up to 3500 km², and its subsurface distribution exceed the boundaries of the study area. The El Huemul Formation consists of a thin lag of glauconitic sandstones with fining-upward log motif, followed by a mudstone-dominated succession that coarsening-upward to sandstones, evidencing a full T-R cycle. Preservation of the El Huemul Formation in the subsurface of the South Flank has been favored by the reactivation of WNW-ESE late Cretaceous normal faults, and by the generation of N–S striking normal faults of Paleocene-Eocene age. Flexural loading associated to igneous intrusions of Paleocene?- middle Eocene age also promoted the increase of subsidence in the South Flank of the basin prior to the transgression.     

寄生性病原血卵涡鞭虫(Hematodinium sp.)感染山东半岛养殖梭子蟹的初步研究

寄生性病原血卵涡鞭虫(Hematodinium sp.)逐渐成为危害我国沿海养殖三疣梭子蟹、锯缘青蟹、脊尾白对虾等蟹虾类的致病性病原。为研究血卵涡鞭虫在我国北方的感染、流行情况,2012年7—11月间,作者从山东半岛三疣梭子蟹的主要养殖区域和邻近海域随机采集梭子蟹样品,进行了血淋巴、组织病理、电镜和分子生物学检测,首次在从胶南和莱州湾养殖区采集的梭子蟹中发现了血卵涡鞭虫感染。在感染血卵涡鞭虫的梭子蟹血淋巴中,共发现了该寄生性病原的四个生活史阶段:丝状滋养体、单细胞滋养体、滋养体聚合体和多核孢子体;该区域发现的血卵涡鞭虫(Hematodinium sp.)形态上与其他报道Hematodinium spp.类似,与在我国东南沿海报道发现的血卵涡鞭虫有亲密的遗传关系;人工感染实验表明该寄生性虫具感染性并对宿主的主要器官造成显著的病理变化。该研究表明血卵涡鞭虫感染养殖蟹类不仅局限于我国东南沿海,在我国北方的养殖蟹类中也存在;这些养殖区普遍采用的混合养殖模式可能一定程度上加剧了该寄生性病原的传播、扩散,因此其传播扩散方式亟需进一步调查研究。     

Modern Dinoflagellate Cysts Distribution off the Eastern Part of Geoje Island,Korea

Distributional characteristics of dinoflagellate cysts in surface sediments were investigated in relation to environmental factors in the eastern part of Geoje Island, Korea. Samples were collected from 10 stations in February of 2004 and water temperature and salinity were measured in February, May, September and November of 2004. Total 30 taxa of dinoflagellate cysts were identified representing 19 genera, 28 species and 2 unidentified species. Among these dinoflagellate cysts,Brigantedinium spp. of which relative proportion in the total dinoflagellate cysts was 23.5%, was the most abundant at all stations except St. 1, and was followed bySpiniferites bulloideus (8.6%),Lingulodinium machaerophorum (8.2%) andDiplopsalis lenticula (6.7%). In addition, ellipsoidal cysts of the genusAlexandrium (Alexandrium catenella - tamarense type) andGymnodinium catenatum, known to be causative organisms for PSP, occurred with high concentrations.Scrippsiella trochoidea was also found; however, its cyst concentration was low. Generally, species composition in the study area was similar to these reported from Jinhae Bay and Busan Harbor and several dinoflagellate cysts reflected the eutrophic condition. Cyst distribution in the eastern part of Geoje Island seems to be influenced by the Tsushima Warm Current flowing from the southwest. The mean water temperature was 12.0°C in February, 14.7°C in May, 20.9°C in September and 17.2°C in November, which was most favorable forAlexandrium spp. growth. The abundances of dinoflagellate cysts ranged from 528 to 2,834 cysts/g dry sediment. Higher concentrations were recognized in sediments of west area of the Jisimdo than at other stations. The cyst composition of this area was closely related to these of Jinhae Bay and Busan Harbor from which currents flow into this area. Higher cyst concentration in the west area of Jisimdo might be due to formation of the gyre.     

一种快速制备甲藻细胞PCR扩增DNA模板的方法

报道了一种快速制备PCR扩增甲藻细胞模板DNA的方法。以赤潮甲藻塔玛亚历山大藻（Alexandrium tamarense）和链状亚历山大藻（Acatenella）为目标藻，对藻液预处理后直接用于PCR扩增，获得5,8S核糖体RNA基因及其两侧的核糖体RNA基因转录单元内基因间隔区（internal transcribed spacer，ITS）序列片段，成功测序。此方法避免了复杂的DNA提取过程。     

1998年春季珠江口海域大规模赤潮原因生物的形态分类和生物学特征I

对１９９８年４月１５日采集于广东珠江口万山群岛桂山岛网箱养殖区的赤潮活体水样 和福尔马林固定样品进行优势种的形态分类和生物学特征的研究。结果发现,三宅裸甲藻 （Ｇｙｍｎｏｄｉｎｉｕｍ ｍｉｋｉｍｏｔｏｉ）是此次赤潮的最优势种,最高密度达到 ７．６ × １０６ｃｅｌｌｓ／Ｌ。另两种优 势种为斯氏多沟藻（Ｐｏｌｙｋｒｉｋｏｓ　ｓｃｈｗａｒｔｚｉｉ）和螺旋螺沟藻（Ｇｙｒｏｄｉｎｉｕｍ ｓｐｉｒａｌｅ）,其最高密度分 别达到 １．１× １０５ｃｅｌｌｓ／Ｌ和 １０４－１０５ｃｅｌｌｓ／Ｌ。此次赤潮的原因生物都属于裸甲藻类,死后或用 福尔马林固定后细胞要么立即裂解,要么变形缩小。有些种类如螺旋螺沟藻在固定样品中找 不到其踪迹,因而无法精确计数。本文描述的３种赤潮藻在细胞、色素体、核、上锥沟和链状群 体等形态构造及外观上与国外学者所描述的几乎完全一致,只是细胞比日本海域产的稍小。 这可能与珠江口海域纬度较日本低有关。电镜照片显示三宅裸甲藻有一明显的上锥沟,斯氏 多沟藻则营养细胞和孢囊同时存在。