The cysts ofCeratium hirundinella: Their dynamics and role within a eutrophic (Lake Sempach,Switzerland)     

U. Pollingher  H. R. Bürgi  H. Ambühl 《Aquatic Sciences - Research Across Boundaries》1993,55(1):10-18

The dynamics of theCeratium hirundinella population and the abundance of dinocysts in the plankton and sediments were studied in Lake Sempach in 1988. In 1987, a rich population ofCeratium (380 cells ml^–1) accompanied byPeridinium spp. developed in the lake. The dinocysts were found entrapped in a kind of flocs, in the deepest part of the lake, in the upper flocculent layer. The number of viable cysts ofCeratium in the sediments decreased gradually from April to July 1988. TheCeratium population increased slowly starting in April, and reached a maximum number in August (31 cells ml^–1).Peridinium willei reached 100 cells ml^–1. Newly formed cysts ofCeratium were recorded in the plankton and sediments at the end of July — beginning of August. They appear in the sediments as separate cells. Their number increased gradually, reaching a maximum of 600 cysts l^–1 at the end of October.Ceratium formed more cysts than didPeridinium, but the rate of survival of theCeratium cysts appears to be lower than that ofPeridinium cysts. In addition to their biological functions, the cysts also have an impact on the ecosystem as carriers of nutrients from down to up and from up to down.  相似文献   

Palynomorph and palynofacies indications of age, depositional environments and source potential for hydrocarbons: Lower Cretaceous Zubair Formation, southern Iraq     

T.K. Al-Ameri  D.J. Batten 《Cretaceous Research》1997,18(6):789-797

Assemblages of miospores and dinoflagellate cysts encounterd in core samples three boreholes drilled in southern Iraq an Aptian-mid Albian age-range for the Zubair Formation, the largest oil reservoir in southern Iraq and neighbouring Kuwait. Four types of palynofacies have been identified, and are interpreted to indicate delta top swamp and marsh, delta front, prodelta and marine platform environments respectively. Amorphous matter comprises more than 50% of the organic component of some of the palynofacies in the upper part of the Zubair Formation. The rocks with which they are associated are highly rated as a potential source of liquid hydrocarbons. Those deposits yielding less than this (down to 12%) are considered to have moderate potential.  相似文献   

Abundance and distribution of dinoflagellate cysts in Xiamen Western Harbor     

CAO Wenqing  LIN Yuanshao  FANG Luping 《海洋学报(英文版)》2004,23(3)

In a grid investigation, dinoflagellate cysts were collected from sediments in Xiamen Western Harbor in May of 2000,from which five species of cysts were identified: Alexandrium tamarensis, A. minutum, Lingulodinium polyedra,Gonyaulax scrippsae and Gymnodinium catenatum, account for about 21% in the species composition. The quantitative analysis of the sediments shows that the number of dinoflagellate cysts varies from 51 to 256 cysts/g of sediment, the highest value (>200 cysts/g) being recorded at the stations of the central part of the bay, while the lowest (＜100 cysts/g) at the bay mouth. A good linear relationship is found between cyst amount and fine-grained sediments. Complex physiognomies on the seabed, topographty in the bay and weak water exchange are the main factors not only in cyst accumulation but also in their distribution pattern, and have resulted in the difference in cyst densities between the inner bay and the outer bay in the harbor.  相似文献   

用钨酸钠分离法研究诏安湾甲藻休眠孢子     

顾海峰  蓝东兆 《台湾海峡》2001,20(1):132-133,T006

本文介绍了一种分离富集沉积物中甲藻休眠孢子的新方法－钨酸钠法，并用这种方法在诏安湾沉积物中分离到了12种甲藻休眠孢子。  相似文献   

厦门西港甲藻孢囊种类和数量分布特征   总被引：8，自引：3，他引：8  

林元烧  曹文清  Sameer TERDALKAR  张茜  齐雨藻 《海洋与湖沼》2002,33(4):407-414

采用超声波分离、网筛（28μm和95μm）过滤、重液（CdI-KI)浮选等方法，对采自厦门西港的7份沉积物样品进行了分析鉴定。结果表明，厦门西港有甲藻孢囊5属10种，其中小型亚历山大藻（Alexandrium minutum)为中国沿海首次记录。沉积物中甲藻孢囊数量范围为18.2-138ind/g沉积物（湿重），高数量密集区主要分布在内湾水域；表层至表层以下2cm沉积物中的孢囊数量明显多于3-5cm底层的。孢囊数量的分布格局与本港的地形、水交换条件密切相关，不同的养殖类型对孢囊的沉降和积累也有重要影响。  相似文献   

Hemolytic activity and fatty acids composition in the ichthyotoxic dinoflagellate Cochlodinium polykrikoides isolated from Bahía de La Paz, Gulf of California     

Juan Jos Dorantes-Aranda  Luz María García-de la Parra  Rosalba Alonso-Rodríguez  Lourdes Morquecho 《Marine pollution bulletin》2009,58(9):1401-1405

The hemolytic activity of the dinoflagellate Cochlodinium polykrikoides from Bahía de La Paz, Gulf of California was investigated as part of the ichthyotoxic mechanism of this microalga. Two different kinds of erythrocytes, fish and human, were tested for the hemolytic assay. Since fatty acids have been associated with hemolytic activity in C. polykrikoides, the composition of fatty acids of this dinoflagellate was also analyzed. The concentration of C. polykrikoides causing 50% hemolysis (HE₅₀) was 4.88 and 5.27 × 10⁶ cells L⁻¹, for fish and human erythrocytes, respectively. According to the standard curve of saponin, an equivalence between the hemolytic activity of saponin and the dinoflagellate concentration was found with 1 μg saponin mL⁻¹ equivalent to 1 × 10⁶ cells L⁻¹ of C. polykrikoides. The polyunsaturated fatty acids: hexadecaenoic (16:0), docosahexaenoic (22:6 n3) and octadecapentaenoic (18:5 n3) were found in an abundance of 62% of total fatty acids.  相似文献   

Dinoflagellate cysts in recent marine sediments from Thermaikos Gulf, Greece: Effects of resuspension events on vertical cyst distribution     

A. Giannakourou  T.Y. Orlova  G. Assimakopoulou  K. Pagou 《Continental Shelf Research》2005,25(19-20):2585

A qualitative and semi-quantitative study of recent dinoflagellate cysts has been undertaken in the NW part of Aegean Sea, Thermaikos Gulf (Eastern Mediteranean), before (September 2001), during (October 2001) and after 120 days (February 2002) of intensive trawling activities. This is the first survey of recent dinoflagellate cysts from Greek marine coastal environments. Sediment samples were collected with a corer and the vertical distribution of the cysts was studied at five different layers, from 0 to 10 cm. Dinoflagellate cysts were both abundant and diverse. Cysts were found over the whole sampling area and periods, with concentrations ranging between 247–3202 cysts cm⁻³. Thirty-six cyst types were encountered, of which 32 were identified to species level, representing 12 genera. It seems that significant local resuspension, related to the onset of the trawling period and stirring up of the sediment, contributed to mixing of the upper layers, resulting to more homogenous cyst profiles in the sediment. Viable cysts constituted 16–60% of the total cyst abundance. The abundance peaks of viable cysts within the subsurface sediment layers, observed during the undisturbed period, disappeared during October. In February, the reduction of cyst concentration was associated to a loss of viable cysts, whilst the ratio of viable/empty cysts ranged between 0.30 and 0.67. The abundance of the different dinoflagellate species, in their active form, was monitored in order to detect any relationship between the concentration of cysts in the top 10 cm of sediment and blooms of algae in the water column. Cysts of potentially toxic species, causing Paralitic Shellfish Poisoning (PSP), such as Alexandrium cf. tamarense, A. cf. affine, A. cf. minutum, as well as Gymnodinium catenatum, were detected in the cyst survey.  相似文献   

Palynodinium minus sp. nov., a new dinoflagellate cyst from the Cretaceous–Paleogene transition in New Zealand; its significance and palaeoecology     

Pi Suhr Willumsen   《Cretaceous Research》2006,27(6):954-963

This is the first record of a representative of the organic-walled dinoflagellate cyst genus Palynodinium from the New Zealand region. Previously, Palynodinium grallator has been reported from two sites in offshore Tasmania during Ocean Drilling Program, Leg 189. The new species Palynodinium minus is found consistently in latest Maastrichtian? and earliest Danian strata (latest Haumurian–earliest Teurian) in two sections located along the mid-Waipara and Grey rivers, North Canterbury, South Island. It occurs in a narrow stratigraphic interval at the Cretaceous–Paleogene transition and is potentially a stratigraphically important index species in the region. Its range coincides with that of the global earliest Danian index fossil Carpatella cornuta and a basal Danian acme interval of Trithyrodinium evittii, and is correlated to ca. 65.5–65.2 Ma. Its highest occurrence is at the base of an acme interval of Palaeoperidinium pyrophorum. It has only been recorded from sections composed of siliciclastic shelf sediments, suggesting that it might have had a palaeoecological preference for relatively near-shore environments.  相似文献   

Historical deposits of Alexandrium catenella resting cysts in the sediments of Queen Charlotte Sound,New Zealand     

AL MacKenzie  S Webber  AM Watts  A Tonks 《新西兰海洋与淡水研究杂志》2016,50(2):195-208

In 2011, a large repository of resting cysts of the toxic dinoflagellate Alexandrium catenella was discovered in the sediments of the Onapua/Opua inlet located off Tory Channel, Queen Charlotte Sound. The inlet is a potential source of infection for other areas, such as the major mussel-growing areas of Port Underwood and Pelorus Sound. This study aimed to establish whether the dinoflagellate was a new arrival in the Sounds or had existed unnoticed in this isolated embayment for some time. Alexandrium catenella cysts were identified to a depth of 20–21?cm within the sediment cores, corresponding to a date estimated by radioisotope (²¹⁰Pb and ¹³⁷Cs) and Pinus radiata pollen distribution to at least the mid 1970s. Over this time span, resident populations of A. catenella have not become established beyond the confines of Queen Charlotte Sound, suggesting it does not pose an imminent threat of doing so unless increasingly intense and prolonged blooms result in more widespread cyst dispersal.  相似文献   

Dinoflagellate biostratigraphy at the Campanian-Maastrichtian boundary in Zumaia,northern Spain     

《Cretaceous Research》2014

Dinoflagellate cyst assemblages from a well-exposed uppermost Cretaceous section at Zumaia (northern Spain) provide a basis for comparison with previous biostratigraphic and magnetostratigraphic studies on the problematic location of the Campanian-Maastrichtian boundary in the section. The position of the last occurrence of Corradinisphaeridium horridum and first common occurrence of Alterbidinium acutulum, correspond well with the bioevents defining the Campanian-Maastrichtian boundary in the Global boundary Stratotype Section and Point of Tercis les Bains (130 km to the North). Together with other age-diagnostic dinoflagellate cyst bioevents, we suggest that the boundary should be placed between 239.75 and 224.75 m below the Cretaceous-Palaeogene boundary, about 46 m lower than an interpretation based on the first occurrence of the planktonic foraminifer Pseudoguembelina palpebra and the last occurrence of the nannofossil Broinsonia parca subsp. constricta. A conspicuous acme of the dinoflagellate cyst Thalassiphora cf. delicata is encountered around the lower-upper Maastrichtian boundary (calibrated by foraminiferal, calcareous nannoplankton and magnetic polarity data), which may prove to be a useful correlatable event.  相似文献