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Seasonal variations of phytoplankton diversity in the Coleroon coastal waters, southeast coast of India 总被引：1，自引：0，他引：1
The results of an investigation carried out during June 2005 to May 2007 on physico-chemical parameters,species composition and community structure of phytoplankton including Chlorophyll a(Chl-a) at the Coleroon coastal waters(Southeast coast of India) are reported.Air and surface water temperatures(°C) varied from 25.1 to 30.1 and from 24.5 to 28.5 respectively.Salinity values varied from 6 to 28.5 and the pH ranged between 7.0 and 8.3.Variation in dissolved oxygen content was from 3.1 to 7.5 mg/dm-3 while the light extinction coefficient values(LEC) ranged between 3.1 and 10.1 cm.The ranges of inorganic nutrients(μmol/dm-3) viz.,nitrate,nitrite,phosphate and silicate were 10.1-23.4,1.2-8.9,0.2-3.1 and 55-125,respectively.The ranges of Chlorophyll a(μg/dm-3) values was 2.0-7.5.Presently,124 phytoplankton species representing different classes viz:Bacillariophyceae(77),Dinophyceae(19),Cyanophyceae(15),Chlorophyceae(10) and Chrysophyceae(3) were recorded.The phytoplankton cell abundance varied from 0.290 to 111.662 cells/cm-3,with peak diversity(3.38 bits/ind.) during summer season.The maximum abundance was found during summer season coinciding with the stable hydrographical conditions.The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters.Canonical Correspondence Analysis(CCA) was applied in this paper for discriminating environmental factors having effect on phytoplankton community at species level.Coleroon coastal water is subjected to long term fluctuations in physico-chemical parameters depending upon the seasonal tidal amplitude and freshwater influx resulting in a continuous exchange of organic,inorganic,plant and animal matters. 相似文献
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The gastric shield and underlying stomach epithelium of Chlymas ffarreri were examined at the light and ultrastructural levels.The results showed that the gastric shield consisted of two different size lobes joined together by a narrow middle piece,the thicker lobe was shaped like a funnel,but unclosed at the lateral side;the other lobe was irregularly triangular-shaped.The transverse section of the thicker lobe was obviously laminated and gradually decreased in thickness from the peak to the margins of the shield.The underlying epithelium bore numerous about 3μm diameter spherical processes formed by the apical plasmalemma of the epithelial cells becoming blunt pseudopodia.Microvilli and some interspersed cilia were present in the areas among the spherical processes regions where only microvilli existed.Rough endoplasmic reticulum,Golgi apparatus,different-sized electron-dense secretory granules and electron-lucent vacuoles as well las abundant mitochondria were present in the underlying epithelial cells.Fused droplets of the secretion from the underlying epithelial cells formed the gastric shield. 相似文献
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体外培养兔角膜上皮细胞和基质细胞,采用显微观察和MTT相结合的方法分析低分子量氨基糖(包括壳寡糖(chitosan)、羧甲基壳寡糖(Carboxymethyl chitosan oligosaccharide)、羧甲基甲壳寡糖(Carboxymethyl chitin oligosaccharide)、N-乙酰氨基葡萄糖(N-acetyl-glucosamine))对细胞生长的影响。结果在0~1000μg/mL浓度范围内4种氨基糖对角膜上皮细胞和基质细胞均没有细胞毒性,且均能促进角膜上皮细胞的生长,以壳寡糖和羧甲基甲壳寡糖效果最佳,二者与对照组相比均具有显著性差异(P<0.05)。壳寡糖、羧甲基甲壳寡糖和N-乙酰氨基葡萄糖能明显促进角膜基质细胞的生长,与对照组相比具有显著性差异(P<0.05),其中壳寡糖的促进作用最明显。提示低分子量氨基糖可适用于角膜细胞促生长的培养,为壳聚糖衍生物材料用于眼科研究提供一定的实验依据。 相似文献
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目的：观察咀嚼槟榔对大鼠口腔黏膜鳞状上皮细胞的影响。方法：将82只SD大鼠随机分成4组，其中对照组（CON组）10只，槟榔提取液涂抹组（T组）24只，机械刺激组（S组）24只，槟榔提取液涂抹+机械刺激组（T+S组）24只，干预10周后自由饮食饲养2周。观察各组大鼠干预6、8、10、12周的一般状态及口腔黏膜鳞状上皮细胞的变化。结果：槟榔化学成分及粗纤维均可损害口腔黏膜，造成大鼠口腔黏膜上皮破坏、增生，但其严重程度T+S组＞T组≈S组＞CON组。结论：与单一刺激相比，采用化学刺激与机械相结合方法可诱发出较典型、稳定的大鼠口腔黏膜鳞状上皮损伤。 相似文献
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用透射电镜观察中国对虾肝小管。指出肝小管管壁由六种细胞（胚细胞、纤维细胞、疱状细胞、吸收细胞、侏儒细胞、肌上皮细胞）组成。描述六种细胞的超微结构，并根据各种细胞的结构特点，探讨其功能。 相似文献
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围食膜(Peritrophic matrix,PM)是无脊椎动物肠道内包围摄入食物的一种特殊结构,是由几丁质纤维网在黏附于其上的蛋白质(围食膜蛋白)相互作用下形成的半通透性膜状结构[1]。已发现的围食膜有两种类型,即I型和II型[2]。I型围食膜是由中肠上皮细胞分泌并覆盖于整个中肠表面;II型则由贲门附近的细胞分泌,随着取食产生,包在食物表面并随着消化废物排出体外[3]。类似于脊椎动物消化道的黏液层,它是中肠上皮细胞和食物之间的一个物理屏 相似文献
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作者在研究CHIMEHERB人工皮肤覆盖创面时发现;人工皮肤与创面之间先是一种液面连接,随着创面渗出的减少,出现一种凝胶状的纤维结合蛋白(FN),使人工皮肤牢固地敷贴创面.在愈合过程的不同时期,进行了组织学切片观察和创面物质的生物化学分析.证实:人工皮肤下的纤维结合蛋白与创面上的多种酶聚集,净化了内环境,为上皮细胞生长提供了营养,对烧伤创面起到了良好的保护和促进愈合作用. 相似文献