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Hypoxia likely compromises the reproductive success of those marine organisms carrying out external fertilization because their gametes and embryos are inevitably exposed to the external environment. Hydroides elegans, a dominant serpulid polychaete in Hong Kong waters, can spawn throughout the year but the number of recruits drops during summer when hypoxia commonly occurs. This study attempted to explain such observation by investigating the gamete quality, including sperm motility, egg size, complexity and viability, after 1-h hypoxic exposure (1 mg O2 l1). In addition, how gamete quality affects fertilization success and embryonic development was examined. After 1-h hypoxic exposure, sperm motility was significantly reduced, compromising fertilization success. Although the eggs remained viable, more malformed embryos and retarded embryonic development were observed. We interpreted that the harmful effect of hypoxia on embryonic development was attributed to the teratogenicity and induced oxidative stress, ultimately causing the reduction in recruitment during summer.  相似文献   
2.
The hatching process of the Pacific abalone Haliotis discus hannai was prolonged at a pH of 7.6 and pH 7.3, and the embryonic developmental success was reduced. The hatching rate at pH 7.3 was significantly (10.8%) lower than that of the control (pH 8.2). The malformation rates at pH 7.9 and pH 8.2 were less than 20% but were 53.8% and 77.3% at pH 7.6 and pH 7.3, respectively. When newly hatched larvae were incubated for 48 h at pH 7.3, only 2.7% of the larvae settled, while more than 70% of the larvae completed settlement in the other three pH treatments. However, most 24 h old larvae could complete metamorphosis in all four pH treatments. Overall, a 0.3-unit reduction in water pH will produce no negative effect on the early development of the Pacific abalone, but further reduction in pH to the values predicted for seawater by the end of this century will have strong detrimental effects.  相似文献   
3.
以 10 - 6 M和 10 - 5 M的视黄酸体外处理草鱼 ( Ctenopharyngodon idellus)早期胚胎 ,结果发现其影响了胚胎的形态发育 ,影响其中轴器官的形成和神经系统的分化 ,使胚胎前部结构全部或部分缺失 ,由此诱导的神经器官 ,如眼、听囊、嗅囊等缺失或不分化 ,胚胎的尾部缩短 ;同时也减少了色素细胞的形成。并且这种畸形程度随着处理浓度加大 ,时间加长而加剧。但在原肠中期以后处理的胚胎 ,神经系统发育基本正常 ,因此说明视黄酸并不抑制原肠作用和随后的神经诱导。它可能是通过抑制某些基因的表达从而影响神经外胚层的区域性分化。  相似文献   
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Elevated frequencies of abnormal embryos in female eelpout Zoarces viviparus have been demonstrated in Danish, Swedish and German monitoring programmes at certain geographic locations with high levels of anthropogenic input. Pollutants present in areas with high malformation frequencies were selected and tested in a controlled laboratory experiment for their potential to induce abnormalities among eelpout embryos upon injection into pregnant eelpout. Tributyltin, 2,3,7,8-tetrachlorodibenzo-p-dioxin, pyrene, nonylphenol, 2,2′,4,4′-tetrabromophenylether and heptadecafluorooctanesulfonic acid were tested, either individually or combined. Generally, the chemicals were transferred to eggs and/or embryos. Some of the exposures increased the proportion of broods with more than 10% abnormal or 5% malformed embryos, although the average percentages of abnormal development were not affected. Spinal, cranial and eye deformities were evident, similarly to what is seen in nature. Some of the exposures resulted in increased percentages of females with as well a low reproductive capacity as embryos with a low condition index.  相似文献   
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