有关长江流域鱼类资源保护的几个问题

2007年11月29~30日,"长江流域水生态环境与经济可持续发展研讨会暨《长江流域资源与环境》第七次编委会"在上海市华东师范大学召开。会议围绕当前长江流域经济社会发展的关键问题———长江流域水生态环境与经济的协调发展问题展开了热烈而深入的学术讨论,来自全国各地的20多位编委专家参加了此次会议,华东师范大学等高校的相关专业师生到会听取了大会发言。本次会议由华东师范大学与《长江流域资源与环境》编委会联合主办,得到了华东师范大学资源与环境科学学院、河口海岸研究院和长江流域发展研究院的大力支持。《长江流域资源与

新疆伊犁地区夏季浮游动物群落结构特征

2006年6—7月在新疆伊犁地区对伊犁河干流、三大支流(特克斯河、巩乃斯河和喀什河)、恰甫其海水库、吉林台水库、间歇性水体和小水塘中的浮游动物进行了调查.共鉴定浮游动物134属217种,其中原生动物95属153种,占浮游动物物种数的71%;轮虫27属51种,占23%;枝角类7属8种,占4%;桡足类5属5种,占2%.伊犁河干流、小水塘和间歇性水体浮游动物种类数较多,分别达132、114和92种,吉林台水库种类数最少,仅7种.浮游动物密度和生物量均以恰甫其海水库最高,分别为11391ind.L-1和2.79m

美国鲥鱼对我国淡水生态系统的潜在入侵风险(英文)

近年来美国鲥鱼已被引入到我国的上海和广东等地进行水产养殖。本实验报道了在纯淡水人工养殖条件下美国鲥鱼的繁殖和生长情况。人工养殖鲥鱼的生长速度接近美国北卡罗莱纳州沿岸野生鲥鱼的生长速度,而高于特拉华河野生鲥鱼的生长速度;人工养殖的2龄鲥鱼既可以在养殖池中自然产卵,也可以通过注射激素人工诱导产卵,其平均受精率、孵化率和仔鱼17天内的存活率分别约15%、75%和54%。这一结果表明,尽管鲥鱼是在海水中进行繁殖的洄游性鱼类,但在生长环境适宜的淡水条件下同样可以正常生长,并达到性成熟和繁育后代,有可能在适宜的淡水水

蓖齿眼子菜对栅藻和微囊藻的他感作用及其参数

主要报道篦齿眼子菜 (俗称红线草 )的种植水抽滤液对栅藻、微囊藻生长的他感作用试验。应用修正的逻辑斯谛 (Logistic)方程和Lotka Volterra种群竞争模型来计算篦齿眼子菜对藻类的他感作用参数。纯培养试验结果表明 :种植水抽滤液对栅藻生物量和生长率都有一定的促进作用。当浓度大于等于 5 0 %时 ,对栅藻生长的影响则是有抑制效应 ,他感作用效应与种植水的浓度没有明显的相关性 ,他感作用参数平均为 - 0 0 2 6。所有浓度设对照。微囊藻的生长都有明显的抑制作用 ,他感作用参数平均为 - 0

长江江豚对八里江江段的利用及其栖息地现状的初步评价

通过定点和流动观察的方法 ,作者使用行为指数和栖息地利用指数定量分析了长江江豚 (Neophocaenaphocaenoidesasiaeorientalis)于 1996～ 2 0 0 0年间对八里江江段的利用和选择状况。结果表明 :江豚在八里江江段的行为指数大小顺序为摄食 >抚幼 >玩耍 >休息 ,摄食和抚幼是江豚在八里江江段的优势行为 ;江豚栖息于离岸距离 10 0～ 30 0m的近岸带占 81 8% ,栖息于水深小于 9m的水区占 73 3% ;江豚分布密度随水深增加而逐步递减 (典型的指数分布

鲫鱼囊胚细胞干扰素的诱导及部分特性

用紫外线灭活的草鱼呼肠孤病毒 (GCRV)诱导鲫鱼囊胚细胞 (CAB)能产生一种高滴度的抗病毒物质。这种物质在 5 6℃及 pH 2～ 11稳定 ;对胰蛋白酶敏感 ;抗病毒活性受被保护细胞的密度、培养温度及保护时间的影响 ;不能被GCRV的特异性抗体中和 ;无直接杀病毒作用 ;抗病毒机制依赖于细胞内RNA和蛋白质的合成 ;在多种鱼类培养细胞中具有抑制病毒作用。这些特性与哺乳类α/ β干扰素一致 ,是一种鲫鱼干扰素

养虾水体环境因子变化与对虾病毒病之间的关系

研究养虾水体的盐度、溶氧量及pH值等主要理化指标的变化与对虾暴发性病毒病害大流行之间的关系 .以低剂量病毒感染中国对虾 (Penaeuschinensis) ,人工改变海水盐度、溶氧量、pH值等理化指标 ,发现其变化与对虾发病死亡之间存在明显的诱发关系 .结果对阐明对虾暴发病毒性流行病成因及指导虾农科学养虾具有重要参考价值 .

水体腐殖酸对甲氰菊酯的生物可利用性与急性毒性的影响

本文在实验室淡水试验系统中，研究了天然水体腐殖酸对甲氰菊酯对草鱼（Ｃｔｅｎｏｐｈａｒｙｎｇｏｄｏｎｉｄｅｌｌｕｓ）的生物积累和急性毒性的影响。研究结果表明：当水体中腐殖酸浓度为５和１０ｍｇ／Ｌ时，甲氰菊酯对草鱼的生物可利用性以及它对草鱼的急性毒性均呈有意义地减少趋势，而且这种影响的程度随着水体腐殖酸浓度的增加而增大。

三倍体白鲫的生物学特性

由人工诱导的异源四倍体白鲫雄鱼与正常的二倍体白鲫雌鱼交配获得的异源三倍体白鲫，其主要生物学特性同二倍体白鲫进行比较研究表明，三倍体白鲫具有体形较大、相对体高和相对尾柄高较高、侧线上下鳞数目较多的形态特征，仍保留着二倍体白鲫以浮游植物为主的植食性营养方式，雌雄均不育，比二倍体生长快，网箱养殖１１２天后，体重比二倍体平均增加３２．３８％。试验证实三倍体白鲫是一个具有养殖生产前景的新对象。

Isolation of a novel cyanophage infectious to the filamentous cyanobacterium Planktothrix agardhii (Cyanophyceae) from Lake Donghu, China

A previously unknown cyanophage, PaV-LD (Planktothrix agardhii Virus isolated from Lake Donghu), which causes lysis of the bloom-forming filamentous cyanobacterium P. agardhii, was isolated from Lake Donghu, Wuhan, China. PaV-LD only lysed P. agardhii strains isolated from Lake Donghu and not those isolated from other lakes. The PaV-LD particle has an icosahedral, non-tailed structure, ca. 70 to 85 nm (mean +/- SD = 76 +/- 6 nm) in diameter. PaV-LD was stable at freezing temperature, but lost its infectivity at temperatures >50 degrees C. Lysis of host cells was delayed about 3 d after the PaV-LD treatment with chloroform, and the virus was inactivated by exposure to low pH (<= 4). The latent period and burst size of the PaV-LD were estimated to be 48 to 72 h and about 340 infectious units per cell, respectively. The regrowth cultures of surviving host filaments were not lysed by the PaV-LD suspension. To our knowledge, this is the first isolation and cultivation of a virus infectious to the filamentous bloom-forming cyanobacterium Planktothrix from a freshwater lake.

Detection of the hepatotoxic microcystins in 36 kinds of cyanobacteria Spirulina food products in China

Gel filtration chromatography, ultra-filtration, and solid-phase extraction silica gel clean-up were evaluated for their ability to remove microcystins selectively from extracts of cyanobacteria Spirulina samples after using the reversed-phase octadecylsilyl ODS cartridge for subsequent analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The reversed-phase ODS cartridge/silica gel combination were effective and the optimal wash and elution conditions were: H2O (wash), 20% methanol in water (wash), and 90% methanol in water (elution) for the reversed-phase ODS cartridge, followed by 80% methanol in water elution in the silica gel cartridge. The presence of microcystins in 36 kinds of cyanobacteria Spirulina health food samples obtained from various retail outlets in China were detected by LC-MS/MS, and 34 samples (94%) contained microcystins ranging from 2 to 163 ng g(-1) (mean=1427 ng g(-1)), which were significantly lower than microcystins present in blue green alga products previously reported. MC-RR-which contains two molecules of arginine (R)-(in 94.4% samples) was the predominant microcystin, followed by MC-LR-where L is leucine-(30.6%) and MC-YR-where Y is tyrose-(27.8%). The possible potential health risks from chronic exposure to microcystins from contaminated cyanobacteria Spirulina health food should not be ignored, even if the toxin concentrations were low. The method presented herein is proposed to detect microcystins present in commercial cyanobacteria Spirulina samples.

Estimation of the detection probability for Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) with a passive acoustic method

Yangtze finless porpoises were surveyed by using simultaneous visual and acoustical methods from 6 November to 13 December 2006. Two research vessels towed stereo acoustic data loggers, which were used to store the intensity and sound source direction of the high frequency sonar signals produced by finless porpoises at detection ranges up to 300 m on each side of the vessel. Simple stereo beam forming allowed the separation of distinct biosonar sound source, which enabled us to count the number of vocalizing porpoises. Acoustically, 204 porpoises were detected from one vessel and 199 from the other vessel in the same section of the Yangtze River. Visually, 163 and 162 porpoises were detected from two vessels within 300 m of the vessel track. The calculated detection probability using acoustic method was approximately twice that for visual detection for each vessel. The difference in detection probabilities between the two methods was caused by the large number of single individuals that were missed by visual observers. However, the sizes of large groups were underestimated by using the acoustic methods. Acoustic and visual observations complemented each other in the accurate detection of porpoises. The use of simple, relatively inexpensive acoustic monitoring systems should enhance population surveys of free-ranging, echolocating odontocetes. (C) 2008 Acoustical Society of America.