Uptake of palytoxin‐like compounds by shellfish fed Ostreopsis siamensis (Dinophyceae)

Abstract

Greenshell? mussels (Perna canaliculus Gmelin), scallops (Pecten novaezealandiae Reeve), and Pacific oysters (Crassostrea gigas Thunberg) were fed with a New Zealand strain of mass cultured Ostreopsis siamensis Schmidt (for 27 and 84 h and with 1.5 × 10⁶ or 8.6 × 10⁶ cells, respectively) under laboratory conditions. The microalgal cells contained 0.3 pg palytoxin equivalents cell^–1 (as determined by the haemolysis neutralisation assay (HNA) of Bignami (1993)) and extracts of these cells were toxic to mice after intraperitoneal injection. No palytoxin‐like material was detected either in the hepatopancreas or the muscle and roe of mussels fed O. siamensis. Oysters contained detectable amounts of toxin in hepatopancreas muscle, and roe while higher concentrations were present in the hepatopancreas of scallops. Extracts of control shellfish (tested biotoxin free and not fed O. siamensis) were toxic to mice, and there was no definitive evidence that feeding shellfish with O. siamensis at the levels employed in the present experiment increased the toxicity of shellfish tissue extracts to mice.     

2015-2016年长江口及其邻近海域甲藻群落与阿米巴藻感染的周年变化

通过2015年2月-2016年1月间在长江口及其邻近海域开展的10个航次调查,研究了该海域浮游甲藻的群落特征和时空变化,分析了寄生性甲藻阿米巴藻宿主种类及其感染率的周年变化。研究结果表明：调查海域浮游甲藻群落结构相对稳定,共检出浮游甲藻类38种,膝沟藻目处于绝对优势,优势种全年既有交叉又有演替;各季节间浮游甲藻丰度差异不显著（P>0.05）,但各月间浮游甲藻丰度差异显著（P<0.05）;全年丰度在9.06×10³-6.10×10⁶ cells/L之间,其中4月份甲藻丰度最高,2月的丰度最低,全年的平均丰度为6.62×10⁵cells/L。调查海域阿米巴藻宿主甲藻种类繁多,14种浮游甲藻被寄生感染,感染率范围为0.006%-5.13%;该海域阿米巴藻宿主种类及感染率表现出明显的季节差异,夏、秋两季宿主种类较多,感染率也明显高于春、冬两季。     

有毒甲藻Coolia monotis Meunier的研究 Ⅰ.甲板形态

经NaClO解离处理,得到Cooliamonotis的甲板板式如下：Po,3’,7”,6c,6s,5”’,2””。电镜照片显示,其甲片表面光滑,分布有圆形或椭圆形的小孔,此外无其他纹饰。     

新疆巴里坤湖卤虫卵孵化率的研究

研究了我国新疆维吾尔自治区巴里坤湖（43.6°N,92.8°E）产的卤虫卵的采收方法、贮存条件对孵化率的影响和提高孵化率的几种化学和物理处理方法。据此设计了巴里坤湖卤虫卵的加工工艺流程,为进行规模性开发利用盐湖卤虫卵资源打下基础。     

Abundance and distribution of dinoflagellate cysts in Xiamen Western Harbor

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 quanti-tative 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.     

长江口甲藻孢囊与水体富营养化和厄尔尼诺指数关系研究

甲藻孢囊是一种可用于追溯环境变化历史的生物微化石,如指示水体富营养化和气候变化,但是如何指示水体富营养化存在争议,并且如何区分甲藻孢囊中的水体富营养化信号和气候变化信号也是一个科学难题.为了研究这两个科学问题,我们利用长江口海域受到水体富营养化和厄尔尼诺事件双重影响的特点,在该海域不同位置采集了4根沉积柱,分析了其中的...     

Chrysophycean cysts in Sierra Nevada (California) lake sediments: paleoecological potential

Thirty-three lakes in the Sierra Nevada range of California were investigated as part of a paleoecological study of the potential effects of acid deposition on sensitive lake/watershed ecosystems. Chrysophyte cysts from surface sediment samples were analyzed and compared with data on pH and alkalinity. This paper identifies the twenty-five dominant chrysophyte cyst taxa and provides information on their morphology, abundance, distribution and ecology.Chrysophycean cysts were generally abundant and well-preserved in lake sediments of our study sites. Twelve taxa occurred in more than twenty of the thirty-three lakes; these taxa were often quite abundant. In contrast, only nine taxa occurred in ten or fewer lakes. Abundance Weighted Mean (AWM) pH varied from 6.45 to 8.34 and AWM alkalinity varied from 46 to 588 eq/L. We delineated pH preference categories, based on AWM pH values and frequency diagrams of cyst abundance vs. lake-water pH. We classified five taxa as acidophilous, nine as circumneutrals, six as alkaliphilous and five as indifferent. Given that the cyst types differ greatly in their abundance relative to pH and alkalinity, it is clear that they have potential for paleolimnological studies of Sierra lakes biogeochemistry.     

常用中文专著中浮游甲藻学名使用的若干问题

学名是每个物种在国际上通用的唯一合法名称,且体现了物种的分类信息,如果使用有误会给学术交流和研究造成诸多不便,甚至造成混乱.为了促进中国海域浮游甲藻学名的规范使用,本文依据《国际藻类、真菌和植物命名法规》(《深圳法规》)的规则要求,以AlgaeBase藻类数据库中的有效拉丁名为基础,对当前国内较常用的中文海洋生物分类学...     

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-N和DONts加富培养条件下,舟形藻(Navicula spp.,优势度60.4%)、丹麦细柱藻(Leptocylindrus danicusm,56.6%)和密连角毛藻(Chaetoceros densus,57.4%)等硅藻是优势种,在DONss加富培养条件下,春膝沟藻(Gonyaulax verior,60.2%)等甲藻为优势种,说明硅藻主要吸收无机态营养盐成为优势种,而甲藻能够吸收DON成为优势藻。动力学过程分析发现,春膝沟藻(G.verior)等甲藻可以直接吸收利用DONss,而DONts可能是通过矿化转化为无机氮,再被密连角毛藻(C.densus)等硅藻吸收与利用。本文研究成果,有助于对硅藻向甲藻演替的营养盐动力学控制机制的认识。     

Pollen analyses off Senegal: Evolution of the coastal palaeoenvironment during the last deglaciation

Pollen and dinoflagellate cysts from marine sediments in core A180-48 (15°19′N, 18°06′W; 2450 m water depth; 530 cm length) are used to reconstruct palaeoenvironmental conditions of nearshore tropical west Africa during the last deglaciation. High concentrations and influxes of pollen and dinoflagellate cysts between 11 000 and 10 000 yr BP are interpreted as reflecting an increase in continental trade-wind circulation and related coastal upwelling at 15°N latitude. The sea-surface temperature difference between glacial and interglacial times was not as strong as previously suggested. Together with local (fresh) ground-water input, this smaller temperature difference may explain the persistence of the Rhizophora mangrove and Guinean gallery forests near the shore until their massive extension during the early Holocene humid maximum around 9500 yr BP. Pollen data from the core are compared with data from Rosilda N110-Z, from the continental shelf at the same latitude.