夜光藻配子细胞实时荧光定量PCR检测方法的建立与应用     

张樱馨  宋书群  李才文 《海洋与湖沼》2022,53(6):1385-1395

夜光藻是我国广泛分布的赤潮原因种之一,其有性繁殖在种群增长中的作用尚不明确,定量分析配子细胞是研究夜光藻有性繁殖过程的重要手段。利用实时荧光定量PCR技术,以夜光藻rRNA基因的18S-ITS1为靶区域,建立了定量检测夜光藻配子细胞的方法。以配子细胞基因组DNA和含目的片段的重组质粒分别建立标准工作曲线,二者均呈现良好的线性响应,检出限分别为每反应0.17个细胞和10²个拷贝,满足定量检测应用需求。应用该方法对2015年逐月采集的胶州湾环境样品进行检测,并首次对夜光藻配子细胞的季节变化、水平分布与垂直分布进行了研究。结果表明,调查海域夜光藻配子丰度呈冬末春初、夏季双峰分布,范围为18.12~9.70×10⁵ cells/L;在水深小于10m的湾内近岸站位,配子丰度较低,垂直分布均匀;在湾中心、湾口和湾外的深水站位,配子丰度较高,仅在2~3月、7月和11月出现垂向差异。夜光藻配子细胞对种群增长和存续有潜在的积极意义,其丰度在营养细胞丰度高值期相对较高,在营养细胞丰度极低时仍可普遍检出。丰富了对近岸海域夜光藻配子细胞时空分布的认识,为深入研究夜光藻的种群增长模式、进一步探究其赤潮暴发的内在机理奠定了基础。  相似文献   

Does the zooplankton prey availability limit the larval habitats of pike in the Baltic Sea?     

Meri Kallasvuo  Maiju Salonen  Antti Lappalainen 《Estuarine, Coastal and Shelf Science》2010

The objectives of this study were to (1) investigate whether the availability of suitable zooplankton prey limits the distribution of the coastal larval areas of pike (Esox lucius) in two archipelago areas of the northern Baltic Sea and (2) compare the availability of zooplankton prey in spring between different types of coastal littoral habitat. According to the results, reed belt habitats formed by Phragmites australis constitute hot spots for zooplankton prey in the coastal ecosystem. During the spring, reed-covered shores of the inner archipelago maintained more than 10 times higher densities of copepods and cladocerans, the preferred prey for larval pike, compared to the other studied shores. Temperature conditions were also most favourable in the reed belt habitat. Thus, the reed belts of the inner and middle archipelago were shown to form the best habitat for larval pike in the coastal area of the northern Baltic Sea, and this was also the only habitat where pike larvae were found. Our results suggest that the poor survival and recruitment of pike in the outer archipelago, however, cannot exclusively be explained by sub-optimal feeding conditions of the larvae. There are also other important factors, presumably connected to the exposure to the open sea, that affect the distribution of the pike larvae. Our results, however, highlight the importance of sheltered coastal reed belt shores as reproduction habitat for spring-spawning fish in the northern Baltic Sea. Further, this study disproves the assumption that the seaweed bladder wrack (Fucus vesiculosus) forms a reproduction habitat for pike in the coastal area.  相似文献   

Map Libraries     

Mingguang Wu  A-Xing Zhu  Li He 《The Cartographic journal》2013,50(3):273-278

Colour distortion, which is caused by the unavoidable mismatch between a map’s gamut and a device’s gamut, negatively affects the semiotic quality of maps. Cartographic communication often suffers from undesirable colour inconsistency. This method models cartographic colour reproduction as a constrained transform problem, namely, adapting a map’s gamut to fit a device’s gamut while preserving the semiotic quality. First, the characteristics of the map’s gamut are investigated by considering cartographic principles, and the fundamental concerns of preserving semiotic quality are proposed. Then, the self-organizing map method is introduced to iteratively optimize the cartographic colour reproduction. We implement this method and evaluate it based on a series of thematic maps. The results indicate that the proposed algorithm offers better results than two alternatives in terms of facilitating cartographic colour reproduction.  相似文献   

单巢类轮虫有性生殖的研究进展与展望     

孙栋  牛翠娟 《湖泊科学》2013,25(2):171-187

作为轮虫动物门的主体,单巢类轮虫是淡水浮游动物的重要组成部分.它们通常作为一类主要的初级消费者在淡水生态系统中起着重要作用,因而深入了解它们在自然水体中的种群动态及其决定机制对淡水生态系统理论与应用研究都有重要意义.作为一类具有典型周期性孤雌生殖生活史的动物,有性生殖的发生和进化策略对其种群动态和进化都有重要影响,因而单巢类轮虫有性生殖的机理和进化研究一直是轮虫学研究领域的一个核心内容.本文就当前单巢类轮虫有性生殖的主要研究进展,包括其发生机理、信息素、理论模型、影响因素和相关实证研究等进行了系统综述;特别就单巢类轮虫有性生殖策略的三个理论模型:"bang-bang"模型、中等有性生殖比率模型和非延迟的有性生殖模型进行了详细论述.此外,本文还对影响单巢类有性生殖的内外源因素进行了总结,主要的外源因素包括食物的浓度及种类、温度、盐度和特殊的细菌等,而主要的内源性因素则包括母体年龄、食物浓度诱导的跨代母系效应、延迟的有性生殖和其他一些潜在的母系效应因素等.其中,因为延迟的有性生殖现象广泛存在且可能是轮虫物种共存或克隆共存现象的一种潜在解释,所以就此现象的理论模型、机理和实证研究等方面进行了深入讨论.另外,本文还简要讨论性比率资源分配与单巢类轮虫有性生殖的关系.最后,对未来几个可能的热点方向简单评述,以期为国内轮虫学和相关方面的研究提供帮助.  相似文献   

The New Zealand species of Spaniocerca (Plecoptera,notonemourinae) and a generic correction in the notonemourinae     

M. J. Winterbourn 《新西兰海洋与淡水研究杂志》2013,47(1):29-36

Variability within the genus Spaniocerca has been studied, and as a result S minor Kimmins has been synonymised with S. zelandica Tillyard. S zelandica is redescribed, the larva is figured, notes on ecology are given, and the nature of the variation found is discussed. Notonemoura cowleyi Winterbourn is transferred to Spaniocercoides Kimmins.  相似文献   

Ocnus sacculus new species (Echinodermata: Holothuroidea), a brood‐protecting holothurian from southeastern New Zealand     

David L. Pawson 《新西兰海洋与淡水研究杂志》2013,47(3):227-230

A new species in the dendrochirotid holothurian genus Ocnus sensu lato is described from approximately 600 m depth in Taiaroa Canyon, off Otago, New Zealand. Ocnus sacculus new species has single rows of tubefeet only in the 3 ventral radii. Body‐wall ossicles consist of cups, knobbed 4‐holed buttons, and multi‐layered plates averaging 0.7 mm in diameter. Three brood pouches lie anteriorly on the inner surface of the body wall in 3 dorsal interradii; the mid‐dorsal pouch is largest. The pouches apparently have no permanent contact with the exterior; presumably birth takes place by rupture of the body wall.  相似文献   

Sexual size dimorphism in calanoid copepods (Centropagidae) from Patagonia (Argentina)     

RD Garcia  M Reissig 《新西兰海洋与淡水研究杂志》2013,47(4):504-514

Calanoid copepods of the genus Boeckella and Parabroteas (P. sarsi) are dominant in zooplankton communities of Patagonian lakes and ponds. This study addresses the occurrence of sexual size dimorphism in calanoid copepods of the genus Boeckella and in the monospecific genus Parabroteas occurring in 12 lakes and ponds of Patagonia (Argentina). The morphometric analysis performed showed that in all the species studied the female is larger than the male, although the difference in size among sexes was found to be variable between species. Interestingly, all species showed significant intraspecific stability in their sexual size dimorphism despite potential differences in their environments regarding predation pressure, environmental stability (permanent or temporary waters) and altitude distribution of populations. Finally, we discuss the potential implications of sexual dimorphism in terms of resource use and vulnerability to predation among other environmental forces which may play a role in promoting larger female to male size.  相似文献   

Aspects of the biology and fisheries of an economically important sparid Dentex macrophthalmus (Bloch 1791) in the Namibe province,Angola     

《African Journal of Marine Science》2013,35(3):601-611

The sparid Dentex macrophthalmus is a widespread, important fishery species along most of the West African coast from southern Namibia to the Mediterranean. In southern Angola it is an important artisanal species targeted predominantly by handline fishers. A biological and fisheries study was conducted on this species in southern Angola between June 2008 and July 2009. It was the dominant species in the artisanal fishery, accounting for 99% of the sparids captured and 67% (by mass) of the total catch. The life history of D. macrophthalmus was characterised by slow growth (females: L_t = 309[1 ? e^{?0.06(t + 5.43)}], males: L_t = 248[1 ? e^{?0.16(t ? 1.77)}]), advanced age at maturity (females: 7.4 years, males: 6.0 years) and high longevity (females: 36 years, males: 38 years). The sex ratio was 1:1 male:female. The length- and age-frequency distributions and macroscopic observations suggested that the species is a late gonochorist. Males and females reached 50% maturity at 151 and 166 mm fork length respectively. Although individuals with ripe gonads were found during most of the year, the peak spawning period appeared to be in December and January. Despite a life history that renders D. macrophthal-mus vulnerable to overexploitation, only 38% of artisanal fishers noticed a decline in the catches of this species. Potential reasons for this include: technology creep; limited pressure on the juvenile portion of the stock as a result of late recruitment (above the length of 50% maturity); the ‘basin affect’, whereby depleted areas are reseeded by areas (e.g. deeper water) inaccessible to the linefishery; and a deep-water reserve of large individuals. It is recommended that precautionary management strategies be implemented until the age estimates are revised by the countries in which this species forms significant fisheries.  相似文献   

Snapper tagging in north‐east New Zealand, 1974: Analysis of methods,return rates,and movements   总被引：1，自引：1，他引：0  

James Crossland 《新西兰海洋与淡水研究杂志》2013,47(4):675-686

During 1974, 5045 snapper Chrysophrys auratus (Forster) were tagged at various locations along the north‐east coast of the North Island. Most were trawl‐caught using a canvas cod‐end in shallow inshore areas. Four types of tags were used, of which two were found to be effective: a large single‐barbed dart tag, and a lock‐on spaghetti tag. For the period up to the end of October 1975, 88 (1.74%) were returned. Highest returns were from the Hauraki Gulf (2.3%) and lowest from Northland (nil). Analysis of the recapture data showed that most movements were local, with a mean distance between tagging site and recapture position of 13.9 nautical miles (25.7 km). Four movements greater than 50 miles (92.6 km) were recorded. Local movements in the Hauraki Gulf were associated with the spring/summer spawning period. This movement, out from inshore areas which are closed to seiners and trawlers, and schooling behaviour, are thought to be the main factors contributing to the peak in snapper catches at this time of the year.  相似文献   

The population genetic structure of the waratah anemone (Actinia tenebrosa) around New Zealand     

AJ Veale  SD Lavery 《新西兰海洋与淡水研究杂志》2013,47(4):523-536

The genetic structure of populations is often shaped by the reproductive system and larval properties of the species. The waratah anemone (Actinia tenebrosa) reproduces through both asexual clones, which have very short-distance dispersal, and sexual larvae, which are believed to disperse much greater distances. The impact of this mixed strategy on the New Zealand population structure of Actinia tenebrosa was investigated using microsatellite markers. The analysis incorporated 24 sampling locations from around New Zealand and one Australian location, using four microsatellite markers, n = 420. We observed low connectivity and high genetic differentiation between all locations sampled, with a distinct pattern of isolation by distance. The most distinct grouping of locations sampled was the north-east of the North Island from Cape Reinga to East Cape, which was identified by SAMOVA and STRUCTURE analyses as being moderately diverged from the remainder of the country. A tentative correlation was observed between genetic clustering and biogeographic regionalisation, where the distribution of a number of genetic clusters matched previously defined biogeographic regions. Within each location sampled, large numbers of clones were present and a latitudinal cline was observed in the relative contribution of asexually and sexually generated recruits, with an increase in asexual recruits on the South Island's east coast.  相似文献