人工湿地中试系统基质中藻类组成的研究

从2003年3月到2004年2月,在水力负荷为600mm/d的条件下研究了人工湿地中试系统(mediumscaleplot,MSP)基质中藻类的组成.结果表明,栅藻、小球藻、盘星藻、空星藻、纤维藻、舟行藻、小环藻、平裂藻和颤藻属的一些种类在下行池基质各层不同季节均有出现,下行池表层藻类较丰;上行池基质中不同季节的藻类组成中念珠藻和鱼腥藻均为固氮种类,菱板藻、舟行藻和卵形藻属的一些种类在上行池表层出现较多,上行池藻类组成较下行池少.本实验探讨了在人工湿地基质中存在的藻类组成,为湿地除藻机理和评估系统的稳定性

香溪河库湾春季水华期间水体光学特征及相关分析

研究了香溪河库湾春季水华期间(2006年3月3日—4月16日)透明度水层可见光衰减系数KSd的时空特征,分析其与表层水叶绿素a浓度、DOC浓度和透明度Sd的相关关系。结果表明:香溪河库湾春季水华可见光衰减系数KSd时空变异很大;除峡口河段(样点X7—X8)外,可见光衰减系数KSd的变化特征取决于叶绿素a浓度和DOC浓度的时空变化,类似于深水湖泊;除峡口河段(样点X7—X8)外,香溪河库湾可见光衰减系数KSd和透明度之间呈反比的关系具有显著的相关,但它们之间的反比关系因水体叶绿素a和无机悬浮颗粒的空间差异而

抚仙湖外来黄颡鱼种群的年龄和生长特征

黄颡鱼(Pelteobagrusfulvidraco)是近年被无意引入到抚仙湖的外来鱼类,自2002年以来在渔获物中已形成了较为稳定的产量。根据2002年9月至2005年5月采集的708尾标本对抚仙湖黄颡鱼种群的年龄和生长特征进行了研究。以脊椎骨作为年龄鉴定的材料,表明种群的年龄分别为雌性0+-5+龄6个龄组和雄性0+-7+龄8个龄组组成;拟合的VonBertalanffy生长参数为雄性L∞=294·68mm,k=0·2476/y,t0=-0·0298y,W∞=209·93g;雌性L∞=257·13mm,

中国淡水产奥杜藻属的分类研究

对我国淡水产奥杜藻属植物的分类进行了研究总结,共有10种2变种,其中4个种为我国的新记录种,即赫曼奥杜藻Audouinellahermannii(Roth)Duby,大孢奥杜藻A.macrospora(Wood)SheathetBurkholder,优美奥杜藻A.eugenea(Skuja)Jao和矮小奥杜藻A.pygmaea(Kützing)Weber-VanBosse。

铜锈微囊藻两种表型的生长生理特性及毒素组成比较分析

从滇池蓝藻水华中分离得到的铜锈微囊藻群体在实验室无机营养中解聚成单细胞 ,结果表明 ,群体微囊藻的生长速度明显低于单细胞微囊藻 ;前者具明显可见的胞外酸性多糖胶鞘 ,而单细胞则几乎没有 ;按常规方法分析比较两种细胞形态的毒性大小和毒素组成 ,发现群体微囊藻主要含有三种微囊藻毒素的异构体 ,而单细胞以MC LR为主 ;且单细胞微囊藻的毒性约为群体的 1 0倍。二者的LDH和PGM同工酶酶谱也有差异。本研究为解释毒素的合成和调控机理提供了新的证据

人工诱导异源四倍体、新四倍体及异源三倍体白鲫的细胞遗传学研究

作者比较了第一代异源四倍体鱼、异源三倍体鱼、新四倍体鱼与亲本白鲫、红鲫及其杂交一代的染色体组型。三种亲本的二倍体染色体数均为100，但其组型分组各有差异，白鲫染色体组型公式：12m＋36sm＋32st十20t,NF＝148，在亚中着丝点组中有一对特大的标记染色体；红鲫染色体组型：20m＋34sm＋26st＋20t,NF＝154；白鲫×红鲫杂种染色体组型：16m＋35sm＋29st＋20t,NF＝151，有一条与白鲫相似的特大标记染色体，证实其组型由白鲫和红鲫各提供一套染色体组组成。异源三倍体的染色体数为1

华鳈的繁殖生物学

根据野外调查和室内养殖的结果,华鳈一龄即达性成熟,绝对怀卵量在1040—5580粒之间,相对怀卵量为83.3—209.6;繁殖季节为4月下旬至7月中旬,繁殖高峰期在5月中下旬;繁殖群体主要由一、二龄组成,雌雄性比为1:1;精母细胞和卵母细胞都有分批成熟现象;卵分批产于流水中,为漂流性。最后对其繁殖习性进行了较为详细的分析。

江豚背部小齿的超微结构与功能

长江江豚背部皮肤表面有一长条小齿,由1—3排组成。它是由表皮向体表突起而成。小齿区皮肤中的乳头深深伸入表皮,几达表面,它的高度在成体约占整个表皮厚度的70—80％,新生幼儿为84.6％。经研究,我们发现在小齿区皮肤中存在着大量类似于人类皮肤中的环层小体那样的被囊神经末梢和几种有鞘神经纤维束。根据这些结构,我们认为小齿是一种感觉器官,它并不能起到防止幼儿从母体背部滑落的作用。

用浮游植物的生产量估算武昌东湖鲢鳙生产潜力与鱼种放养量的探讨

本文根据浮游植物生产量求得对鲢、鳙的供饵能力,并通过浮游植物对鲢、鳙转化效率的计算,估算出武昌东湖鲢、鳙的生产潜力,进而求得武昌东湖鲢、鳙的合理投放量。作者求得东湖浮游植物全年对鲢、鳙的供饵能力是61,153吨(鲜重);由此估算出东湖鲢、鳙的生产潜力是789公斤/公顷以上,每年鱼种(四寸以上)的合理投放量,鲢是 209万尾,鳙是 110万尾。

中国粒鲇属Akysis鱼类二新种

<正> 粒鲇科Akyisidae鱼类是分布在东南亚地区的小型鱼类,包括三个属。其中大粒鲇属Achrochodomchthys Bleeker只产于苏门答腊岛、爪哇岛和加里曼丹岛。狭尾粒鲇属Breitensteinia Steindachner只产于苏门答腊岛和加里曼丹岛。粒鲇属Akysis Bleeker鱼类已记录的有下列8种:Akysis variegatus(Bleeker),1846;Akysis macronemus Bleeker,1860;Akysis pictus Gnther,1883;A

黑龙江流域鲫鱼的种群变异和生态资料

<正> 黑龙江流域的鲫鱼,是渔获物中的主要粗成之一,约占总产量的20%。黑龙江流域的水利枢扭建成后,它将成为水库中的主要养殖对象,因此,调查研究鲫鱼的生活习性及其种群变异,对于今后的渔业利用是有很大益处的。一、种群的变异鲫鱼在黑龙江流域的分布极其广泛,各种不同的水体中都能棲息生存。在额尔古纳河,鲫鱼是捕捞的主要对象;在黑龙江,则主要是分布在干流相通的附属水体中。其它如达赖湖、镜泊湖、小兴凯湖、五大连池等湖泊里均有相当数量的鱼群。

中国淡水鱼寄生桡足类鳋科的研究

<正> 一.绪言桡足类的主要组成部分是自由生活的剑水溞(Cyclopoida)和镖水溞(Calanoida),它们都是鱼类的优良食料。另一部分就是营寄生生活的种类,其中有些对于鱼类的危害性很大。鳋科(Ergasilidae)是一群由自由生活的剑水溞演变成寄生生活的过渡类型,其幼虫及雄虫完全营自由生活,只有雌性的成虫始寄生在鱼体上。因此过去如 Gurney氏等认为它们是半寄生性的种类,是很正确的论断。

Localization and tracking of phonating finless porpoises using towed stereo acoustic data-loggers

Cetaceans produce sound signals frequently. Usually, acoustic localization of cetaceans was made by cable hydrophone arrays and multichannel recording systems. In this study, a simple and relatively inexpensive towed acoustic system consisting of two miniature stereo acoustic data-loggers is described for localization and tracking of finless porpoises in a mobile survey. Among 204 porpoises detected acoustically, 34 individuals (similar to 17%) were localized, and 4 of the 34 localized individuals were tracked. The accuracy of the localization is considered to be fairly high, as the upper bounds of relative distance errors were less than 41% within 173 m. With the location information, source levels of finless porpoise clicks were estimated to range from 180 to 209 dB re 1 mu Pa pp at 1 m with an average of 197 dB (N=34), which is over 20 dB higher than that estimated previously from animals in enclosed waters. For the four tracked porpoises, two-dimensional swimming trajectories relative to the moving survey boat, absolute swimming speed, and absolute heading direction are deduced by assuming the animal movements are straight and at constant speed in the segment between two consecutive locations.

Floral survey of the diatom genera Cymbella and Gomphonema (Cymbellales, Bacillariophyta) from the Jolmolungma mountain region of China

We report on taxa from the diatom genera Gomphonema and Cymbella (Cymbellales, Bacillariophyta) found in the Jolmolungma Mountain region of China. This region is unique for its diversity of habitats, which include rivers, springs, moist soil, snowfields, swamps and lakes. We re-examine diatom taxa found in samples first documented in 1973 (Jao et A, 1973) and incorporate recent taxonomic revisions from the literature. In the genera Gomphonema and Cymbella we report 113 species and varieties. Of these 113 taxa, 59 are new record for China; 1 new combination, Encyonema jolmolungmensis, is made. Morphometric data and habitat features are reported for each taxon. Their distribution is strongly correlated to their microhabitats.

Crustacean zooplankton size structure in aquaculture lakes: is larger size structure always associated with higher grazing pressure?

Crustacean zooplankton size structure in 27 aquaculture lakes was studied to test the hypothesis that larger size structure is associated with higher grazing pressure. Mean body length of crustaceans was positively correlated with increasing Chl a (r(2) = 0.40, P = 0.000) and TP (r(2) = 0.38, P = 0.000), contrary to the empirical studies. However, the ratio of zooplankton to phytoplankton biomass decreased significantly with increasing TP (r(2) = 0.27, P = 0.005) and mean body length (r(2) = 0.46, P = 0.000). Meanwhile, size structure showed no significant effect in explaining residual variations of phosphorus-chlorophyll relationship (P = 0.231). These results indicate that larger size structure was not always associated with higher zooplankton grazing pressure. It is likely that in aquaculture lakes crustacean zooplankton size structure was of minor importance in control of phytoplankton biomass, and it was mainly regulated by fish predation. The results showed in our study and the empirical studies might be a reflection of two different stages of lake eutrophication and fish predation intensity.