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Zhongming Huo Zhaoping Wang Jian Liang Yuehuan Zhang Jianping Shen Tuo Yao Jiaqi Su Ruihai Yu 《中国海洋大学学报(英文版)》2014,13(4):666-670
This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artificial seawater at three different salinities (low, 15; medium, 23; and high, 30) to determine the optimum hatchery and nursery conditions for mass production of the seeds. Results showed that the percentage production of straight-hinged larvae from fertilized eggs was significantly lower at the high salinity than at the low- and medium-salinities (P < 0.05). The survival rates of larvae and juveniles differed significantly among the three salinity trials, with the highest survival rate observed at the low salinity (P < 0.05). The shell height of larvae was significantly larger at the low salinity than at the high and medium salinities from days 9 to 15 (P < 0.05), whereas that of juveniles was significantly larger at the low salinity than at the high and medium salinities on day 70 (P < 0.05). These results indicate that the larvae and juveniles of C. hongkongensis are tolerant to a wide range of salinities (15 to 30), but show better growth and survival at relatively low salinities. Thus, it is recommended to use relatively low salinities in hatchery and nursery systems for improved yields of C. hongkongensis. 相似文献
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LI Gang LIN Qiang SHEN Pingping NI Guangyan SONG Xingyu WANG Shengfu FAN Yanzhi HUANG Liangmin TAN Yehui 《海洋学报(英文版)》2013,32(4):77-81
The Strait of Malacca (SoM), the world’s busiest sea-route, is increasingly polluted as the rapid development of world trades, affecting phytoplankton primary productivity therein. The variations of surface phytoplankton biomass, size-structure and carbon fixation were investigated across the SoM during the spring period (May 4 to 9, 2011). Chlorophyll a concentration increased from 0.12 μg/L at the northwest entrance of the SoM to a maximal 0.63 μg/L at narrowest section, and decreased to 0.10 μg/L at the southeast entrance. Photosynthetic carbon fixation by phytoplankton coincided well with Chl a biomass, and increased from 10.8 to 22.3 μg C/(L d), then decreased to 9.21 μg C/(L d); while the carbon fixation rate showed an inverse pattern to the changes of Chl a, and decreased from 87.1 to 35.5 μg C/(μg Chl a d) and increased thereafter to 95.3 μg C/(μg Chla·d). Picophytoplankton cells (<3 μm) contributed to more than 60% and 50% of the total Chl a and carbon fixation at both the entry waters; while the contributions of pico-cells decreased sharply to the minimum of 18.3% and 27.5% at the narrowest part of the SoM. In particular, our results showed that the silicate concentration positively regulated Chl a biomass and carbon fixation, reflecting that the higher silicate favoured the growth of phytoplankton and thus led to higher primary production in this strait. 相似文献
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南海西北部陆架区沿岸流和上升流对中华哲水蚤分布的影响 总被引：2，自引：1，他引：1
中华哲水蚤(Calanus sinicus)是广泛分布于西北太平洋大陆架水域的浮游桡足类,在海洋生态系统的物质循环和能量流动中具有重要作用。根据2006年7月至2007年10月4个季节使用网目孔径为0.505mm的浮游生物网采集的样品,分析了南海西北部陆架区中华哲水蚤的水平、季节和昼夜垂直分布以及与季风、海流和温度的关系。中华哲水蚤丰度季节变化显著,整个调查海域春季的平均达(22.30±77.78)个/m3,夏季的降低,平均为(13.74±45.10)个/m3,秋季消失,冬季调查期间仍未出现。中华哲水蚤的区域分布差异十分显著,将调查海域划分为粤西近海、琼东近海、粤西-琼东外海三个亚区,在粤西近海亚区春、夏季中华哲水蚤的平均丰度分别为(115.63±145.93),(68.12±84.00)个/m3,远高于另外两个亚区。夏季琼东沿岸上升流区的中华哲水蚤没有昼夜垂直移动行为,呈底层分布,以躲避表层高温的伤害。南海西北部陆架区是中华哲水蚤的季节分布区,冬春季东北季风期间由广东沿岸流从东海沿岸携带而来,出现的时间从北往南逐渐推迟;夏季西南季风期间雷州半岛东部近海的冷涡和琼东沿岸上升流区成为中华哲水蚤度夏的避难所;秋季季风转换时期上升流减弱或消失,中华哲水蚤因耐受不了高温(>27℃)死亡而消失。因此,中华哲水蚤对东北季风时期的沿岸流和西南季风时期的上升流均具有良好的指示作用。 相似文献
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The seaweed Sargassum hemiphyllum is widely distributed throughout the coastal waters of Asia and has high commercial value.In recent years,its natural biomass has declined due to over-exploitation and environmental pollution.To seek for a feasible way to culture this seaweed efficiently,we designed a simple long-line system in a shrimp pond for the culture during winter,and the growth and nutritional composition of the seaweed were examined.Results show that the culture system was durable and flexible allowing S.hemiphyllum to grow vertically off the muddy bottom of the pond.Although the length of pondcultured S.hemiphyllum was inhibited by water depth,the weight-specific growth rate((1.65±0.17)%/d) was nearly three times higher than that of wild plants((0.62±0.19)%/d).The crude protein(6.92%±0.88%) and ash content(21.52%±0.07%) of the pond-cultured seaweed were significantly lower than those of the wild plants(9.38%±0.43% and 26.93%±0.07%,respectively);however,crude fat(1.01%±0.04%) was significantly higher than that of the wild plants(0.87%±0.02%).In addition,the nutritional composition of both pond-cultured and wild S.hemiphyllum was comparable to or even higher than those of other common seaweeds being used as food and/or aquaculture fodder.Future studies shall be focused on the impact of environmental parameters on its growth and nutritional composition. 相似文献
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Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea(SCS) in early summer(May 16 to June 7) of 2009.In most areas of southern SCS,the concentrations of nitrogen and phosphorus were very low and DIN/DIP ratios usually were lower than the Redfield N/P Ratio of 16:1.Nitrogen nutrients were significant lower in the upwelling region off Vietnam.A total of 144 taxa of phytoplankton were identified in the study area.The dominant genera were Prorocentrum,Gonyaulax,Gyrodinium,Scrippsiella and Chaetoceros,respectively.Spatial patterns of early-summer phytoplankton abundance and species composition should be mainly controlled by the upwelling off Vietnam and the discharge of Mekong River in the southern SCS.Diatoms dominated in the nutritious Mekong River Estuary or upwelling region off Vietnam;while dinoflagellates dominated in the oligotrophic pelagic region.The canonical correspondence analysis(CCA) indicates that most of diatoms favor higher levels of silicate and phosphorus,as well as lower temperature;while most of dinoflagellates favor the lower silicate and phosphorous and higher temperature.Correlation and CCA results indicate that silicate,nitrate and temperature were the most relevant environmental factors to regulate the horizontal pattern of early-summer phytoplankton in the surface waters of southern SCS. 相似文献
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海洋酸化对马氏珠母贝受精及早期发育的影响 总被引：1，自引：0，他引：1
自2010年7月1日至3日,在pH值为8.1、7.7和7.4条件下研究了海洋酸化对马氏珠母贝(Pinctada martensii Dunker)受精及早期发育的影响。结果显示,海洋酸化对不同pH值下马氏珠母贝的受精率无显著影响。pH8.1、pH 7.7和pH 7.4试验组幼虫的壳长、壳高的值逐渐增大,pH 8.1组幼虫的壳长、壳高的值大于同期其他两组的值,且在实验的第24、36、48小时与其他两组同期幼虫的壳长、壳高的值差异显著,这表明海洋酸化显著影响马氏珠母贝幼虫的生长。实验期间,pH 8.1试验组幼虫的存活率和畸形率没有显著变化,而pH 7.7和pH 7.4组幼虫的存活率显著低于pH 8.1组。pH 7.4组幼虫的畸形率显著高于同期pH 8.1和pH 7.7组幼虫的畸形率,表明在海洋酸化的环境中幼虫的发育受到影响。本文将为海洋酸化的相关研究提供基础数据。 相似文献
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生长激素与胰岛素样生长因子-Ⅰ对马氏珠母贝壳生长形成相关基因表达的影响 总被引：1，自引：0，他引：1
研究了外源生长激素与胰岛素样生长因子-Ⅰ处理对马氏珠母贝Pinctada fucata Gould胰岛素相关多肽受体基因(irr)和5种壳基质蛋白基因(nacrein、efcbp、n19、aspein及accbp)表达水平的影响。结果表明,激素处理显著提高了irr基因的表达水平(P<0.05),这与其在软体动物中作为胰岛素样生长因子受体的作用相一致。nacrein基因的表达水平在激素处理组也有显著升高(P<0.05),表明生长激素与胰岛素样生长因子-Ⅰ两种外源激素都增强了马氏珠母贝的生长代谢水平;与对照组相比,n19、aspein与accbp3个基因的表达水平在激素处理组均下调(P<0.05),说明这3个基因的表达受到激素调节通路的抑制作用。此外,研究发现aspein与accbp两个基因的表达在各个实验样本中具有极高的相关性,说明这两个基因在激素通路中可能受到同一个上游因子调控。efcbp基因表达水平在激素处理组与对照组之间表达稳定,各样本之间无显著性的变化(P>0.05)。 相似文献
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Phytoplankton cells in estuary waters usually experience drastic changes in chemical and physical environments due to mixing of fresh and seawaters. In order to see their photosynthetic performance in such dynamic waters, we measured the photosynthetic carbon fixation by natural phytoplankton assemblages in the Jiulong River estuary of the South China Sea during April 24-26 and July 24-26 of 2008, and investigated its relationship with environmental changes in the presence or the absence of UV radiation. Phytoplankton biomass (Chl a) decreased sharply from the river-mouth to seawards (17.3-2.1 μg L−1), with the dominant species changed from chlorophytes to diatoms. The photosynthetic rate based on Chl a at noon time under PAR-alone increased from 1.9 μg C (μg Chl a)−1 L−1 in low salinity zone (SSS < 10) to 12.4 μg C (μg Chl a)−1 L−1 in turbidity front (SSS within 10-20), and then decreased to 2.1 μg C (μg Chl a)−1 L−1 in mixohaline zone (SSS > 20); accordingly, the carbon fixation per volume of seawater increased from 12.8 to 149 μg C L−1 h−1, and decreased to 14.3 μg C L−1 h−1. Solar UVR caused the inhibition of carbon fixation in surface water of all the investigated zones, by 39% in turbidity area and 7-10% in freshwater or mixohaline zones. In the turbidity zone, higher availability of CO2 could have enhanced the photosynthetic performance; while osmotic stress might be responsible for the higher sensitivity of phytoplankton assemblages to solar UV radiation. 相似文献
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Kaizhi LiJianqiang Yin Liangmin HuangJianlin Zhang Shumin LianCuimei Liu 《Continental Shelf Research》2011,31(9):979-989
The distribution and abundance of thaliaceans were studied in relation to physical and biological variables during summer and winter in the northwest continental shelf of South China Sea. Based on the topography and water mass of the surveyed region, it was divided into three subregions: region I (onshore waters of the east Leizhou Peninsula), region II (onshore waters of the east and southeast Hainan Island) and region III (offshore waters from Leizhou Peninsula to Hainan Island). During summer due to a strong southwest monsoon, a cold eddy and coastal upwelling dominated in regions I and II, respectively, whereas the onshore and offshore waters were vertically mixed during winter due to a strong northeast monsoon. A total of 18 thaliacean species (including 3 subspecies) were collected. The mean species richness was higher in summer compared to winter, with the occurrence of higher values during summer and winter at region II and region III, respectively. The average thaliacean abundance is also higher in summer than in winter, with higher values at region I in summer and no significant difference among three subregions in winter. Doliolum denticulatum and Thalia democratica were the dominant species during summer and winter. The results suggested that the seasonal and spatial distribution of thaliacean richness was considered to be the result of physical factors such as temperature and ocean current in summer and winter. Spatial distribution of thaliacean abundance was affected by chlorophyll a concentration increased by the occurrence of coastal upwelling and cold eddy in summer. Southwest and northeast monsoons are shown to play an important role in shaping the distribution of species richness and abundance of thaliaceans in the northwest continental shelf of South China Sea. 相似文献