中国囊裸藻属的新种类

国家自然科学基金

再论白暨豚和江豚的保护

白暨豚（Ｌｉｐｏｔｅｓｖｅｘｉｌｉｆｅｒ）的种群数量已降到了很低的水平，濒临灭绝，长江的自然环境，由于人类活动的加剧而日趋恶化。长江环境已经不可能保存白暨豚，但可能在一个半自然保护区保存下来。中国政府正在考虑集中人力和财力优先建设一个最好的白暨豚半自然保护区，即石首天鹅洲白暨豚半自然保护区，因为目前白暨豚的种群现状已不可能支持１个以上的半自然保护区。１头成熟的雌性白暨豚已于１９９５年捕获并移入石首天鹅洲保护区。江豚（Ｎｅｏｐｈｏｃａｅｕａｐｈｏ－ｃａｅｎｏｉｄｅｓ）也面临着白暨豚所面临的全部威胁。近年来其

团藻目新资料

本文报道湖北省武汉市团藻目7个属的5个新种,2个新变种,2个中国新记录

珞珈山森林土壤原生动物生态学研究及土壤原生动物定量方法探讨

１９９３年１月至１２月，用直接计数法和培养计数法对武昌珞珈山森林土壤原生动物进行了周年定量研究，发现原生动物丰度的周年动态趋势为：春季（３—５月）达到高峰，低谷出现在冬季（１—２月），夏秋季保持较平稳的变动。原生动物丰度与土壤环境因子间的相关性分析结果表明，原生动物丰度的周年动态与土壤含水量及土壤ｐＨ值的变化呈显著的正相关，与土壤温度的变化无明显相关关系。珞珈山森林土壤原生动物优势种为梨波豆虫（Ｂｏｄｏｅｄａｘ）、球波豆虫（Ｂｏｄｏｇｌｏｂｏｓｕｓ）、卵形隐滴虫（Ｃｒｙｐｔｏｍｏｎａｓｏｖａｔａ）、长尾尾

中华双腔吸虫精子发生的超微结构研究

应用透射电镜技术，研究中华双腔吸虫（Ｄｉｃｒｏｃｏｅｌｉｕｍ ｃｈｉｎｅｓｉｓ Ｔａｎｇ ｅｔ Ｔａｎｇ １９７８）的精子发生， 并与其它复殖吸虫进行比较，提出了复殖吸虫精子发生的一般过程，结果显示它与大多数复殖吸虫 精子发生的超微结构相似，原始的精原细胞经过三次有丝分裂，两次减数分裂成为精细胞，它经过 分化、形态变化后成为成熟精子，精子形成共分为六个阶段，其中有以下首次报道的特征：（１）中 央胞质区的生长速度在开始时比鞭毛要快；（２）在鞭毛与中央胞质区融合前，线粒体的前端在中央 胞质区中有段时间比核更接

以底栖动物评价湘江污染的研究

湘江底栖动物种类较丰富,而上游种类尤多,生物多样性明显。中、下游某些江段因污染等因素影响,多样性有差异。shannon多样性指数反映出了这些变化。上游江段属于清洁水体,中、下游多数江段属于轻污染,少数江段为中污染,而霞湾港江段为重污染。进行了水和底泥中化学毒物的含量与生物主要种类的数量变化的相关分析。

粘孢子纲新科的代表——安永七囊虫SEPTEMCAPSULA YASUNAGAI,新属新种

<正> 日本国安永统男先生(Norio Yasunaga, 1981)报道在日本长崎五岛一些养殖场饲养的花鲈 Lateolabrax japonicus发生一种粘孢子虫病,引起严重死亡。他从病鱼脑腔里找到这种病原体的孢囊标本,赠给作者两块,以研究它的形态结构和分类问题。通过对标本的详细观察、研究,认为这种粘孢子虫的孢子,形态结构比较特殊,不仅足以作为独立的属,而且是一新科的代表。

Effects of arsenate on the growth and microcystin production of Microcystis aeruginosa isolated from Taiwan as influenced by extracellular phosphate

Arsenic pollution and eutrophication are both prominent issues in the aquaculture ponds of Taiwan. It is important to study the effects of arsenic on algal growth and toxin production in order to assess the ecological risk of arsenic pollution, or at least to understand naturally occurring ponds. The sensitivity of algae to arsenate has often been linked to the structural similarities between arsenate and phosphate. Thus, in this study we examined the effects of arsenate (10(-8) to 10(-4) M) on Microcystis aeruginosa TY-1 isolated from Taiwan, under two phosphate regimes. The present study showed that M. aeruginosa TY-1 was arsenate tolerant up to 10(-4) M, and that this tolerance was not affected by extracellular phosphate. However, it seems that extracellular phosphate contributed to microcystin production and leakage by M. aeruginosa in response to arsenate. Under normal phosphate conditions, total toxin yields after arsenate treatment followed a typical inverted U-shape hormesis, with a peak value of 2.25 +/- 0.06 mg L-1 in the presence of 10(-7) M arsenate, whereas 10(-8) to 10(-6) M arsenate increased leakage of similar to 75% microcystin. Under phosphate starvation, total toxin yields were not affected by arsenate, while 10(-6) and 10(-5) M arsenate stimulated microcystin leakage. It is suggested that arsenate may play a role in the process of microcystin biosynthesis and excretion. Given the arsenic concentrations in aquaculture ponds in Taiwan, arsenate favors survival of toxic M. aeruginosa in such ponds, and arsenate-stimulated microcystin production and leakage may have an impact on the food chain.

Induction of hepatic cytochrome P4501A1/2B activity and disruption of thyroglobulin synthesis/secretion by mono-ortho polychlorinated biphenyl and its hydroxylated metabolites in rat cell lines

As the active metabolites of polychlorinated biphenyl (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs) are found in wildlife and human tissues. They have been proposed as main contributors for endocrine disruption of PCBs in living organisms. In this study, mono-ortho PCB 156 and its hydroxylated metabolites 4'-OH-PCB 159, 4'-OH-PCB 121, and 4'-OH-PCB 72 were selected to investigate the toxic effects on rat hepatoma H4IIE cell line and rat thyroid follicle FRTL-5 cell line at concentrations of 1, 10(2), 10(4) nM. 7-Ethoxyresorufin-O-deethylase (EROD) and 7-pentoxyresorufin-O-dealkylase (PROD) activities were determined with micro-EROD/PROD to indicate cytochrome P4501 A1 (CYP1A1) and cytochrome P4502B (CYP2B) induction in the H4IIE cell after exposure for 72 h. To assess thyroid disruption of these compounds, thyroglobulin concentrations also were detected inside FRTL-5 cell with immunocellularchemistry and in its medium with radioimmunoassay after exposure for 24 It. Significant inductions of EROD activity by PCB 156 at 102 and 104 nM (p < 0.05) were observed, but no effects by the three OH-PCBs in H4IIE cell line. 7-Pentoxyresorufin-O-dealkylase activities were induced only by 10(4) nM of PCB156 and the three OH-PCBs (p < 0.05). Meanwhile, significant increases of thyroglobulin concentrations were observed in the medium of FRTL-5 cell exposed to 4'-OH-PCB 121 and 4'-OH-PCB 72 at all of the test concentrations (p < 0.05), but not to the other compounds. The results demonstrated that mono-ortho PCBs mainly could be metabolized to hydroxylated metabolites through CYP1A1 instead of CYP2B. Moreover, after being metabolized, OH-PCBs still sustained the ability to induce PROD activity and did exhibit the disruption on thyroglobulin synthesis/excretion in rat cells.

Monitoring of organochlorine pesticides using PFU csystems in Yunnan lakes and rivers, China

Polyurethane foam unit (PFU) systems were collected from 11 lakes and three rivers in the Yunnan Plateau, China and, the PFU extrusion liquids, were analyzed for organochlorine pesticides (OCPs) by gas chromatography with electron capture detection (GCECD). The concentrations of pp'-DDE, HCB and HCHs were undetectable to 1.86 mu g l(-1) (mean 0.27 mu g l(-1)), undetectable to 0.72 mu g l(-1) (mean 0.11 mu g l(-1)), and 0.24-21.95 mu g l(-1) (mean 7.39 mu g l(-1)) respectively in lakes; and those in rivers were undetectable to 0.23 mu g l(-1) (mean 0.08 mu g l(-1)), 0.68-2.93 mu g l(-1) (mean 1.70 mu g l(-1)), and 2.71-37.56 mu g l(-1) (mean 17.01 mu g l(-1)) respectively. Notably, some residue levels of OCPs exceeded the US National Recommended Water Quality Criteria, implying Yunnan has levels of OCPs potentially harmful to human health. Further, the contamination by OCPs showed an obvious spatial distribution pattern. Amongst the lakes, Dianchi, Xingyun, Lugu and Yangzonghai had the highest OCP levels dominated by beta-HCH, whereas among rivers, Nujiang and Lancang Rivers had the highest contents of OCPs dominated by alpha-HCH. This demonstrates that HCHs are the predominant contaminants and some point sources of HCHs may still exist in Yunnan. The pollution levels in Yunnan were compared with other studies, suggesting the PFU method is suitable for long-term on-line monitoring of trace OCPs in aquatic ecosystems. Therefore, continuous studies monitoring OCPs in lakes and rivers are needed to further understand the future trend of contamination. (c) 2006 Elsevier Ltd. All rights reserved.

Kinetics of the oxidation of MCRR by potassium permanganate

The occurrence of the microcystins in the water bodies, especially in drinking water resources, has received considerable attentions. In situ chemical oxidation is a promising cost-effective treatment method to remove MC from water body. This research investigated the reaction kinetics of the oxidation of MCRR by permanganate. Experimental results indicate that the reaction is second order overall and first order with respect to both permanganate and MCRR, and has an activation energy of 18.9 kJ/mol. The second-order rate constant ranges from 0.154 to 0.225 l/mg/min at temperature from 15 to 30 degrees C. The MCRR degradation rates can be accelerated through increasing reaction temperature and oxidant concentration. The reaction under acid conditions was slightly faster than under alkaline conditions. The half-life of the reaction was less than 1 min, and more than 99.5% of MCRR was degraded within 10 min. (c) 2005 Elsevier Ltd. All rights reserved.

Mobilization potential of heavy metals: A comparison between river and lake sediments

Toxic metals introduced into aquatic environments by human activities accumulation in sediments. A common notion is that the association of metals with acid volatile sulfides (AVS) affords a mechanism for partitioning metals from water to solid phase, thereby reducing biological availability. However, variation in environmental conditions can mobilize the sediment-bound metal and result in adverse environmental impacts. The AVS levels and the effect of AVS on the fate of Cu, Cd, Zn, Ni in sediments in the the Changjiang River, a suboxic river with sandy bottom sediment and the Donghu Lake, a anoxic lake with muddy sediment in China, were compared through aeration, static adsorption and release experiments in laboratory. Sips isotherm equation, kinetic equation and grade ion exchange theory were used to describe the heavy metal adsorb and release process. The results showed that AVS level in the lake sediment are higher than that of the river. Heavy metals in the overlying water can transfer to sediments incessantly as long as the sediment remains undisturbed. The metal release process is mainly related to AVS oxidation in lake sediment while also related to Org-C and Fe-Mn oxyhydroxide oxidation in river sediment. The effect of sulfides on Zn and Ni is high, followed by Cd, and Cu is easy bound to Org-C. AVS plays a major role in controlling metals activity in lake sediment and its presence increase the adsorption capacity both of the lake and river sediments.

cDNA cloning and characterization of a novel SNX gene differentially expressed in previtellogenic oocytes of gibel carp

To understand the molecular events governing fish oogenesis, a multiple technique was used to identify the genes differentially expressed at different phases during fish oogenesis. This technique is a combination of suppression subtractive hybridization, SMART cDNA synthesis and RACE-PCR. Here we report the cDNA cloning and expression characterization of a novel SNX gene based on its differential transcription between previtellogenic and fully mature oocytes in naturally gynogenetic gibel carp. First, a cDNA fragment selectively expressed in previtellogenic oocytes was identified and used to screen a SMART cDNA library prepared from the same mRNA sample by RACE-PCR for cloning fully length cDNA. The full length cDNA was 1392-bp long and coded for a novel SNX protein with 225 amino acids. The 5' UTR had 72 bp and 3' UTR had 642 bp. Unlike most of maternal genes that are transcribed after vitellogenesis and stored in oocytes, this gene is expressed at a higher level in the previtellogenic oocytes and at a much lower level in fully matured oocytes. However, RT-PCR analysis of tissues showed it was ubiquitous transcription. The novel gene is named fish sorting nexin (fSNX), because it contains a conserved PX domain. The fact which major expression of the gene occurs in the previtellogenic oocytes suggests that it might have an important function in the oogenesis. (C) 2003 Elsevier Inc. All rights reserved.

Observations on two species of phyllodistomes (Trematoda : Gorgoderidae) from fishes of the Hubei Province, central China, with an erection of Neophyllodistomum gen. n.

Two rare trematode species so far reported in the genus Phyllodistomum Braun, 1899, P. pawlovskii (Zmeev, 1936) and P. serrispatula Chin, 1963, were found in the urinary system the yellow catfish Pelteobagrus fulvidraco (Richardson) of Bao'an Lake (prevalence 8 %) and the swamp eel Monopterus albus (Zouiev) of Liangzi Lake (prevalence 6 9/6), respectively, from the Hubei Province, central China. In contrast to the original description, P. pawlovskii showed a considerable morphological variability particularly in the shape, size and topography of testes. A unique morphological feature of P. serrispatula is the presence of many conspicuous lateral outgrowths on the hindbody and, principally based on this character, a new genus Neophyl-lodistomum is erected (type species N. serrispatula (Chin, 1963) comb. n.)) to accommodate this species. Both trematode species are briefly redescribed. P. pawlovskii and N. serrispatula are reported for the first time from the Hubei Province and the former from the Yangtze River drainage system.

Genetic diversity among different clones of the gynogenetic silver crucian carp, Carassius auratus gibelio, revealed by transferrin and isozyme markers

Genetic diversity among four clones (A, D, E, F) of gynogenetic silver crucian carp was studied using transferrin and isozymes in the blood as markers. Of the five proteins investigated, three (transferrin, esterase and superoxide dismutase) indicated polymorphism and eight polymorphic loci were detected. These loci were probably encoded by codominant alleles and their inheritance patterns were analyzed. Intraclonal homogeneity and interclonal heterogeneity were observed in these clones, which allowed us to infer the clonal nature and evolutionary relationship between them. Clonal diversity in this population of silver crucian carp in China was also compared with data reported from gynogenetic crucian carp in Germany.