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991.
潮间带垒石蒙网养鲍技术研究 总被引:1,自引:0,他引:1
在潮间带进行垒石蒙网养鲍试验,4个岩礁区共设置136个石垛,放养壳长1.3 ̄3.0厘米的鲍55.1万只,经18个月养殖,共产商品鲍19.254吨,平均亩产1397.8公斤,平均壳长6.81厘米,成活率89.6%,实现产值693.144万元,利润352.81万元。该成果1996年被评为青岛市科技进步三等奖。 相似文献
992.
Abstract. In the Sicilian lagoon Stagnone di Marsala, Tethya aurantium and T. citrina show different ecological distributions, although some overlapping occurs. The first species reaches its highest density where linear currents are maximal, and in this habitat it is particularly frequent on Posidonia oceanica rhizomes. The second species is more abundant in still water locations and is equally common on Posidonia rhizomes and on calcareous concretions. Such distributions can be related to water movement, Posidonia shoot density, and associated factors such as sedimentation and food availability. These observations are consistent with an adaptive interpretation of the morphofunctional features distinguishing the two species. 相似文献
993.
Geoffrey R. F. Hicks 《Marine Ecology》1982,3(1):41-51
Abstract. Using data from studies on alga-dwelling harpacticoid copepods from New Zealand and Britain and shallow water decapods from a variety of habitats in the Pacific and Caribbean, an analysis is made of the contribution of physical and biotic habitat structures to the generation and maintenance of crustacean species richness. The relation between the number of species and the complexity of the habitat is, in equilibrium communities, positive and essentially linear. Accordingly, Gray's (1979) and Stenseth's (1979) theoretical predictions are endorsed whereby species-abundance curves are, at equilibrium, expected to follow a log-normal distribution, whereas departures from the log-normal are anticipated in disturbed environments. Such departures reflect either increased dominance or inequalities in the species-abundance hierarchy. Because of their adaptable life-history traits, certain opportunist species are identified as those contributing most to departure points. The impact on community equilibrium of natural disturbance processes such as turbidity, exposure, and substratum transience is assessed. 相似文献
994.
光生态膜对水稻秧苗生态的影响 总被引:1,自引:0,他引:1
采用浮染法将荧光助剂、红外辐射剂、着色剂分散进低密度聚乙烯 (LDPE)树脂中 ,通过挤出吹塑制成厚 0 .1 2 mm,宽 1 2 m的无滴、长寿棚膜。光生态膜将 550 nm的绿光变换为红光提高了红光成分 ,有效的调整了辐射进入棚内的太阳光谱 ,补充了红光的辐射强度 ,改善了农作物的光生态环境 ,促进了作物的光合作用。用这种光生态膜苫盖温室进行水稻育秧 ,在哈尔滨市 1 2个县进行大面积试验示范 ,提高了作物的产量 ,使水稻产量提高了 8.6%。 相似文献
995.
在水槽中进行了几种不同坡度的斜坡平台上规则波作用下直墙波浪力试验,系统分析了直墙上相对最大压强和相对最大总力,给出了它们之间的比较关系。还进行了不同坡度的不规则波模型试验,并讨论了波浪力之间的特性。结果表明采用1:10、1:15的斜坡与平台相结合的试验室模拟,可得到与平底地形相近的直墙波浪力。 相似文献
996.
对海南岛海岸澄迈角沙滩的3个断面进行了潮间带生态调查。初步鉴定无脊椎动物32种,其中软体动物8种,甲壳类14种,多毛类8种,其它动物2种。优势的大型底栖动物有端足类的肢突跳钩虾Talorchestia brito,等足类的日本异浪漂水虱Excirolana japonica和双壳类的等边浅蛤Gomphina aequilatera。垂直分布可分为:(1)钩虾带,以肢突跳钩虾为特征种;(2)等足类带,以日本异浪漂水虱为特征种;(3)蛤-螺带,以等边浅蛤-(虫昌)螺Umbonium vestiarium为特征种。研究表明,沙滩底栖动物垂直分布主要受潮汐、底质、盐度和波浪的影响。 相似文献
997.
Abstract. A mixed population of unicellular and colonial cyanobacteria was transferred into culture from a hypersaline helio-thermal pond in the vicinity of the Dead Sea. The entire complex of strains, incubated in Dead Sea water of varying salinity and temperature, showed a pronounced shift of the maximal growth from a salinity of 72 g l-1 at 30 o C up to 142 g 1-1 at 50 o C. Over the above range of salinities and temperatures, these cyanobacteria were capable of about four divisions per day, providing that any increase in salinity was coupled with the suitable increase in temperature. The above peculiar adaptation can explain the prominent success of this group of microorganisms in the extreme and unstable ecological conditions of hypersaline habitats. Amounts of slime accumulating in the cultures were proportional to the incubation temperature. 相似文献
998.
999.
Abstract. Sponges from muddy and dctritic bottoms along the coasts of Liguria and Tuscany (Western Méditerranean) were studied to 700 m depth. The distribution of the 66 species identified was compared with depth, geographic location, as well as type of bottom and benthic community in order to determine whether a typical sponge fauna exists in these environments. The most common species (Suberites carnosus, S.ficus, Thenea muricata) are characteristic soft bottom dwellers, but the remaining sponge fauna seems to be linked to the presence of small patches of hard substrate scattered on these bottoms. As a consequence, the neighbouring hard bottom biocoenoses may remarkably affect the composition of this fauna by an export of larvae. Many species are clearly eurybathic, but most were recorded between 50 and 200 m. Type and size of the available substrate for sponge settlement and growth are apparently the most important Écological factors affecting the studied fauna. 相似文献
1000.
对杭州湾软相潮间带周年调查,共获底栖动物95种,以甲壳动物(34种)、鱼类(28种)、软体动物(21种)占绝对优势。生态类群以我国沿岸广温广盐性种和半成水特有种为主,生活方式多为活动性和埋栖类型。这与杭州湾水域盐度低且变化幅度大及动力作用强,底质不稳定等因素密切相关。从湾底到湾口,底栖动物种类增多,组成类群逐渐从低盐的河口种向广盐的海洋种演替,表现出明显的湾性分布。种类的垂直分布是中潮区大于低潮区大于高潮区,各类群生物在潮间带呈现随机镶嵌分布,无明显的分带现象。种数的季节分布呈现更、秋两季较多、冬季最少的特点。 相似文献