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41.
中日褐菖鲉群体形态学比较研究   总被引:3,自引:0,他引:3  
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42.
海洋牧场是近岸渔业资源保护和恢复的有效途径,为评估海洋牧场建设对岩礁性鱼类的影响,本文基于马鞍列岛海洋牧场建设前后资源调查数据,利用胃含物分析和稳定同位素测试,研究了褐菖鲉的摄食习性.结果表明:海洋牧场建设前褐菖鲉主要摄食端足类、蟹类和头足类,优势饵料生物种类为麦秆虫、日本枪乌贼、日本蟳、日本岩瓷蟹和滩栖阳遂足等.随体长的增大,蟹类的比例增加,而端足类的比例减少.洋牧场建设后褐菖鲉主要摄食蟹类、端足类和鱼类,优势饵料生物种类为双斑蟳、日本蟳、麦秆虫和赤鼻棱鳀等.随体长的增大,鱼类和蟹类的比例增加,而端足类的比例先增加后减少.根据稳定同位素分析结果,海洋牧场区褐菖鲉可以划分为体长<10.0 cm、10.0~13.9.0 cm和≥14.0 cm 3个摄食群体,平均营养级为3.40级.  相似文献   
43.
本文研究卵胎生硬骨鱼褐菖(Sebastiscusmarmoratus)精细胞的成熟变化和精子结构。褐菖精细胞发育晚期已具有硬骨鱼类精子的结构雏形:细胞核的背面较平坦,腹面稍外鼓,呈弧面;染色质浓缩成团块状,核的腹侧和后端的染色质较致密;中心粒复合体由近端中心粒和基体组成,近端中心粒和基体排成“L”形;近端中心粒向细胞核的背侧伸出中心粒附属物,中心粒附属物由9条微管组成,9条微管围成一筒状结构,类似轴丝。在晚期精细胞形成精子的过程中,中心粒附属物和近端中心粒相继退缩以至消失不见,同时细胞核后端的形状也随着发生变化。中心粒附属物和近端中心粒的相继消失可以看作是成熟的最后标志。精子的中心粒复合体由基体及其上方的基体帽组成,袖套接于核的后端,其中约有30~40个线粒体;鞭毛从袖套腔中伸出,鞭毛的中心结构是轴丝;轴丝外方为细胞质形成的侧鳍,在鞭毛的近核段,轴丝两侧的侧鳍较宽且不对称。  相似文献   
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45.
The effects of ectoparasites on larvae of the clingfish Gobiesox marmoratus were evaluated at the dietary and morphometric levels. The larvae and ectoparasites were collected by nearshore plankton samplings during October, November and December 2013 off El Quisco Bay, central Chile. The standardized abundance of total larvae and those ectoparasitized larvae (PL) was positively related and high parasite prevalence was found throughout the sampling period (up to 38%). Geometric morphometrics analyses indicate main changes in the shape through early ontogeny and subtle but significant variations between PL and non‐parasitized larvae (NPL). Prey composition varied between PL and NPL; small size (<6 mm standard length, LS) parasitized larval G. marmoratus ate mostly gastropod larvae, whereas small non‐parasitized specimens ate mainly cirripede nauplii. All larger (>8 mm LS), pre‐settlement stages parasitized by Trifur and, or Caligus copepods had content in their gut, suggesting that ectoparasites did not diminish prey capture in host with larger size. Morphometric and dietary changes occurring during larval development were decoupled, both for PL and NPL. The maintenance of a slender, more hydrodynamic body through pelagic development and the ingestion of less‐mobile prey in PL suggests non‐lethal effects of ectoparasitism on rocky‐reef fish larvae.  相似文献   
46.
Temperature, salinity, food ration and interactions among them had significant effects on overall growth of hatchlings of the self-fertilizing hermaphrodite Rivulus marmoratus . Low temperature (19° C) suppressed growth. At 26° C, the treatment groups at 12 and 40‰ salinity had higher final wet masses than the group at 1‰. When provided with high food ration, individuals whose parents were provided with low food had a significantly higher specific growth rate in the first month than those whose parents were provided with high food ration. This effect was also found in the final wet masses. It appears that genetic variation in this species occurs only between strains, yet within a strain there is considerable scope for phenotypic plasticity. The combination of a fixed genotype and plastic expression, along with a suite of specialized physiological characteristics, may explain how a self-fertilizing hermaphrodite can thrive in such an abiotically stressful and variable habitat as an estuary.  相似文献   
47.
The collection of a single specimen of the Guinean puffer Sphoeroides marmoratus from the Ionian Sea in September 1977, misidentified at that time as Lagocephalus lagocephalus , shows that this subtropical species of fish has occurred in the Mediterranean Sea from 30 years ago.  相似文献   
48.
Abstract .Truck trap collections of Ceratopogonidae were made over a period of 27 months (November 1973–February 1976) at Tingalpa Creek, in southeast Queensland, Australia. Six collections were made on each of 95 days, giving 570 observations and a total of 29 378 Culicoides . Two collections were made before, one at, and three after sunset. Separate analyses were made of the catches of thirteen entities: male and female C. austropalpalis , C. brevitarsis , C. marksi , C. marmoratus and C. victoriae , female C. henryi and C. longior , and total C. bundyensis .
Catches were dominated by C. brevitarsis (35.2%) and C. marmoratus (32.3%) and, with C. victoriae , were taken on almost every collecting day over all seasons. Sex ratios (M:F) varied from 0:100 for C. longior to 130:100 for C. marksi . Collections of all entities, except female C. henryi , were greatest (50–70% of the daily catch) at sunset. In winter there was substantial activity in the hour before sunset. Time of day was the most important variable, accounting for 15–45% of the observed variation. Between-day differences were significant for all except C. austropalpalis, C. victoriae and male C. marksi . Culicoides brevitarsis, C. bundyensis and C. longior had highly significant annual cycles, C. victoriae and female C. austropalpalis had significant lunar cycles, and C. longior had a significant tidal cycle. Logarithms of catches of female C. austropalpalis, C. brevitarsis, C. henryi, C. marmoratus, and female and male C. victoriae were inversely related to linear wind speed. Log catches of female C. austropalpalis, C. brevitarsis, C. marmoratus and C. victoriae , and male C. marksi and C. victoriae were positively related to temperature (quadratic).  相似文献   
49.
云斑车蝗线粒体基因组全序列测定与分析   总被引:3,自引:1,他引:2  
党江鹏  刘念  叶伟  黄原 《昆虫学报》2008,51(7):671-680
采用长距 PCR 扩增及保守引物步移法并结合克隆测序测定并注释了云斑车蝗 Gastrimargus marmoratus (Thunberg)的线粒体基因组全序列。结果表明:云斑车蝗线粒体基因组全序列为15 904 bp(GenBank登录号为EU527334),A+T含量略高于非洲飞蝗Locusta migratoria,为76.04%,包括13个蛋白质编码基因,22个tRNA 基因,2个rRNA基因和一段1 057 bp的A+T富集区。蛋白质基因的起始密码子中,除COⅠ和ND5为TTG以外,均为昆虫典型的起始密码子ATN。ND5基因使用了不完全终止密码子T,其余基因均为典型的TAA或TAG。预测了22个tRNA基因的二级结构,发现tRNASer(AGN)缺少DHU臂, tRNASer(UGY)的反密码子环上有9个碱基。预测了云斑车蝗12S和16S rRNA二级结构,分别包括3个结构域30个茎环和6个结构域44个茎环。A+T富集区含有3个串联重复序列。  相似文献   
50.
Orientation toward breeding ponds plays an important role in the seasonal movements of amphibians. In this study, adult marbled newts were tested in a circular arena to determine sensory cues used to locate breeding ponds. Animals were collected from a temporary pond situated in northern Spain, taken to the experimental site 340 m distant, and tested for orientation under a variety of conditions (i.e., orientation under a clear night sky, orientation under an overcast night sky, and orientation under a clear night sky in the presence of an altered geomagnetic field). These investigations have demonstrated that the marbled newt is able to orient using celestial cues. Animals chose a compass course in the direction of their breeding pond only when celestial cues were available. Conversely, the ambient geomagnetic field does not seem to be relevant to orientation of marbled newts since they were unable to orient themselves using the ambient geomagnetic field in the absence of celestial cues. Electronic Publication  相似文献   
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