The Phylogenetic Relationships of the Chinese and Vietnamese Waterfall frogs of the genus Amolops

Ranid frogs of the genus Amolops occur in Southeast Asia and are typically found near waterfalls. Their phylogenetic relationships have not been resolved. We include 2,213 aligned nucleotide sites of the 12S, 16S and tRNA(val) gene regions of the mitochondrial DNA genome from 43 individuals of Chinese and Vietnamese Amotops, Huia, Hylarana, Meristogenys, Odorrana and Rana. The outgroup species were from the genera Chaparana, Limnonectes, Nanorana, and Paa. The data were analyzed within the framework of a refutationist philosophy using maximum parsimony. Four clades of waterfall frogs were resolved. Meristogenys was not resolved as the sister group to either Huia nor Amolops. The hypothesis Of evolutionary relationships placed Amolops chapaensis and Huia nasica in the genus Odorrana.

着生刚毛藻处理富营养化湖泊水

分别研究了室内和露天条件下在鹅卵石上着生的刚毛藻Cladophora oligoclona对富营养化湖水中氮(N)和磷(P)的净化效果及其对水华藻类生长的抑制能力,同时对处理后湖水的藻类生长潜力进行了测试.结果显示,刚毛藻在原始浓度总氮(TN)10.512 mg/L和总磷(TP)0.856 mg/L的富营养化湖水中能维持正常的生长代谢,并能有效去除水体中的N、P养分.在室内12 d培养期间,刚毛藻对TN、氨氮(NH4-N)、TP和无机磷(PO4-P)的平均去除率分别达53.13%,44.40%,35.71

体重对暗纹东方鲀摄食影响的研究

利用室内养殖实验研究了暗纹东方鲀的体重与摄食率的关系以及其日粮的变化规律。结果表明,随着体重由12.3g增加到213.2g,摄食率由12.6%下降到2.6%,由于暗纹东方鲀属于偏肉食性鱼类,其日粮变化一般以2天为一个周期呈振荡型变化。

云南漫湾水库甲藻水华生态初步研究

国家 973项目 (2 0 0 2CB412 3 0 0 ); 中国科学院方向性创新课题 (2 2 0 3 16)资助

中华鳖胸腺显微和亚显微结构及其在进化上的意义

应用透射电子显微镜观察了中华鳖胸腺的显微和亚显微结构。发现中华鳖胸腺从结构上可分为皮质和髓质，皮质富含淋巴细胞，髓质富含上皮性网状细胞。在各发育期中华鳖胸腺皮质、髓质交界处和髓质区有明显的囊状胸腺小体和交错突细胞。在200g以上的成年鳖胸腺内发现有同心圆状胸腺小体。电镜下，胸腺内淋巴细胞分为大、中、小3型。上皮性网状细胞从亚显微结构上分为支持型和分泌型。胸腺囊包括细胞内囊和细胞间囊，以细胞内囊居多。部分毛细血管管腔与淋巴细胞之间出现具4层结构的血一胸腺屏障。60g左右幼鳖胸腺部分皮质区已开始出现退化。至5

六六六在水环境中转移、积累和归趋研究——2.斜生栅藻和裸腹溞对六六六的积累

斜生栅藻和裸腹搔对六六六的积累系数分别为213和32(以湿重计);它们的死体也同样能积累六六六。在氧化塘或其他富营养化的水体中,浮游生物在六六六由水向底泥转移中起着载体的重要作用。

淡水青虾幼体发育的初步研究

作者观察了淡水青虾在实验室条件下幼体发育的情况。在幼体发育的全过程中,有的个体蜕皮9次,有的蜕皮11、14次。本文是描述蜕皮9次的个体的发育情况。从第一至第九期幼体以及后期幼体都附有详细的附肢图和部分整体图。幼体发育所需的时间随水温而变,在26.5±1.3℃条件下,幼体完成变态达到后期幼体需21天,在30.9±1-2℃仅需16天。

Oxidative damage in unfertilized eggs of Chinese rare minnow (Gobiocypris rarus) exposed to nonylphenol

In the present study, female Chinese rare minnows (Gobiocypris rarus) were used as in vivo models and exposed to nonylphenol (NP) at concentrations of 1 to 200 mu g/L for 21 d under semistatic conditions. Molecular biomarkers of oxidative stress were measured in unfertilized eggs and included reactive oxygen species (ROS), lipid peroxidation products (thiobarbituric acid-reactive substances [TBARS] and protein carbonyl), superoxide dismutase activity, and glutathione. Cathepsin D activity as an indicator of egg viability also was assayed. Nonylphenol induced ROS formation in unfertilized eggs in all exposed groups compared to the controls. The levels of protein carbonyl and TBARS in unfertilized eggs were significantly increased (p < 0.05) at 10 to 200 and 100 to 200 mu g/L, respectively. Good positive correlations were shown between ROS induction and levels of TBARS and protein carbonyl in eggs (R = 0.918, p < 0.05 and R = 0.784, p < 0.05, respectively). Superoxide dismutase activity in eggs was significantly inhibited (p < 0.05) in the 50 to 200 mu g/L exposure groups. Glutathione levels in eggs were significantly depleted (p < 0.05) at 100 to 200 mu g/L concentrations. In addition, ROS induction resulted in oxidative damage to lipid and protein in chorions. Significant reductions (p < 0.05) of the protein and lipid contents in chorions were both found in the 50 to 200 mu g/L exposure groups. A previous study found that NP exposure could lead to chorion thinning in zebra fish. Thus, the reductions in protein and lipid contents in chorion could be the reason for chorion thinning by NP exposure. Meanwhile, cathepsin D activity was significantly inhibited (p < 0.05) in all exposure groups. The results demonstrated that NP-induced oxidative stress could damage the chorion of unfertilized eggs and lead to a decline in gamete quality in female Chinese rare minnow.