五种淡水藻类植物的采集及观察

有人认为在植物系统学实验中,藻类植物实验材料的采集较为困难。其实只要了解它们的生活环境及其特点,采集并不困难。现介绍五种藻类植物实验材料的采集及观察方法。一、颤藻(Oscillatoria sp.)为常见蓝藻,分布很广,污水沟、湿地、墙壁、甚至在温泉中都可发现。腐殖质丰富的水沟或鱼塘边缘最多,常在污水流经的地表形成一层蓝绿色至黑色的膜状物,或成团漂浮在水面。一年四季均可采到,但在温暖季节生长旺盛。为了得     

水生无脊椎动物细胞培养

目前水生无脊椎动物的细胞培养研究远远落后于哺乳动物和昆虫的培养研究,其培养方法基本仍是套用哺乳动物或昆虫的细胞培养模式。尽管在几十年中进行了一些探索,而且原代培养也取得了一些进展,但到目前为止除了淡水蜗牛胚胎BGE细胞系外,其他动物都还没有成功的建立长时间持续传代的细胞系。现对水生无脊椎动物细胞培养的研究进行综述,并对所面临的主要困难进行了总结,对水生无脊椎动物细胞培养的前景提出了一些看法。     

无脊椎动物内分泌与激素综览

本文简要介绍了近年对非昆虫无脊椎动物内分泌与激素研究动态和各大门类内分泌与激素较成熟的认识。现已明确相似于脊椎动物的内分泌也存在于许多无脊椎动物且有不同功能的多种激素。神经内分泌细胞及其分泌的神经激素、蜕皮激素等激素了解更为系统、深入，研究最多的动物是节肢动物（特别是甲壳类）。     

无脊椎动物的排泄器官

动物机体在新陈代谢过程中 ,不断形成如 CO2 、H2 O及 NH3 等各种代谢产物 ,但不能将这些产物概括为废物 ,因为它们在调节生命活动过程中还起着重要作用。例如 ,CO2 的含量可以调节呼吸运动 ;NH3 虽为有毒物质 ,但在氨基酸代谢中 ,一部分可转化为体内组成成分。只有这些产物积累量超过机体需要时 ,才是有害的。因此 ,所谓排泄是指动物体将新陈代谢的最后产物和整体平衡剩余物排出体外的过程。排泄是动物机体特有的生理机能 ,其生理意义和效果在于 :排出有害的代谢产物 ,特别是氮化物以及多余的水分和盐分 ,使机体取得体内平衡。脊椎动物…     

古生代的海洋无脊椎动物

古生代的海洋无脊椎动物彭以莉编译在研究古生代海洋无脊椎动物群落发生的变化时,我们不一定要把注意力放在无脊椎动物的每一个门上。而是要考察此时期内海洋无脊椎动物整个群落的进化过程,特别是考察进化过程中的主要特征和主要变化。为此,我们先来研究一下现存海洋生...     

鼠妇的采集和培养

介绍了一种用花生麸培养鼠妇的新方法,能够在控制的时间内培养出足够量的鼠妇．保证了实验教学的正常开展。     

涡虫的采集培养和切割再生方法

迄今,我国的淡水涡虫已发现七种,其中最常见的是东亚三角头涡虫(Dugesis iaponicua),分布于香港、台湾、昆明直到吉林省境内,和细形山地涡虫(Phagocato vivida),分布于大、小兴安岭和长白山一带。七种淡水涡虫都喜生于冷泉溪流的石下。采集涡虫时,途中要防止水温的骤升。制作切片的涡虫采集,需将涡虫用稀酸杀生,鲍氏液固定,然后放酒精中带回。用带盖的塘瓷盘加水培养涡虫,既接近生境,便于实验操作和换水,又能使涡虫较好的生殖和产卵。切割再生实验,既能定向地培育出双头、双尾、多头和多尾的畸型涡虫,又能增加超常数眼涡虫出现的频率。     

Collection and culture techniques for gelatinous zooplankton

Gelatinous zooplankton are the least understood of all planktonic animal groups. This is partly due to their fragility, which typically precludes the capture of intact specimens with nets or trawls. Specialized tools and techniques have been developed that allow researchers and aquarists to collect intact gelatinous animals at sea and to maintain many of these alive in the laboratory. This paper summarizes the scientific literature on the capture, collection, and culture of gelatinous zooplankton and incorporates many unpublished methods developed at the Monterey Bay Aquarium in the past 15 years.     

薇甘菊入侵对中小型土壤动物群落结构特征的影响

薇甘菊是菊科假泽兰属的恶性杂草,在我国华南地区已成功入侵并造成严重危害.为了解薇甘菊入侵对土壤动物的影响效应,采用野外样地试验法对广州市火炉山森林公园薇甘菊入侵群落的土壤动物进行了调查.2009年4次采样共获得中小型土壤动物5206头,隶属于4门10纲19类,其中线虫类为优势类群,蜱螨目、弹尾目和轮虫是常见类群.薇甘菊入侵地中小型土壤动物群落结构特征发生了改变,与其他样区相比,入侵区中小型土壤动物的总个体数以及线虫类、蜱螨目的个体数显著增加,但中小型土壤动物类群数的变化不明显;在群落多样性方面,薇甘菊入侵区土壤动物群落的密度-类群指数显著提高,物种丰富度、优势度指数亦有所上升,但差异不明显,而均匀度、Shannon指数趋于下降;在群落相似性方面,薇甘菊入侵区与群落交错区的相似程度较高,与土著植物区的相似程度较低.薇甘菊入侵所引起的局部气候环境、凋落物、根系分泌物与土壤理化性质的变化可能是造成中小型土壤动物群落结构特征改变的主要原因.     

薇甘菊入侵对中小型土壤动物群落 结构特征的影响

薇甘菊是菊科假泽兰属的恶性杂草,在我国华南地区已成功入侵并造成严重危害.为了解薇甘菊入侵对土壤动物的影响效应,采用野外样地试验法对广州市火炉山森林公园薇甘菊入侵群落的土壤动物进行了调查.2009年4次采样共获得中小型土壤动物5206头,隶属于4门10纲19类,其中线虫类为优势类群,蜱螨目、弹尾目和轮虫是常见类群.薇甘菊入侵地中小型土壤动物群落结构特征发生了改变,与其他样区相比,入侵区中小型土壤动物的总个体数以及线虫类、蜱螨目的个体数显著增加,但中小型土壤动物类群数的变化不明显;在群落多样性方面,薇甘菊入侵区土壤动物群落的密度-类群指数显著提高,物种丰富度、优势度指数亦有所上升,但差异不明显,而均匀度、Shannon指数趋于下降;在群落相似性方面,薇甘菊入侵区与群落交错区的相似程度较高,与土著植物区的相似程度较低.薇甘菊入侵所引起的局部气候环境、凋落物、根系分泌物与土壤理化性质的变化可能是造成中小型土壤动物群落结构特征改变的主要原因.     

Collection and culture of live foods for aquaculture in Taiwan

Collection and culture of live foods to be used instudies of feeds for rearing finfish and shellfishlarvae in Taiwan began in 1982. Today, 31 species (49strains) of microalgae, three species (nine strains)of rotifers, one cladoceran and one copepod are holdas start culture. Microalgae are collected from localwaters and obtained from foreign collection centers.The most common genera are Chlorella,Nannochloropsis, Tetraselmis, Chaetoceros, Skeletonema, Isochrysis, and Pavlova. Someinteresting genera such as Ellipsoidion,Nannochloris, Synechococcus, and Alexandriumare also included. Three types of rotifers, i.e. L, S,and SS-type, which are classified as Brachionusplicatilis, B. rotundiformis, and Brachionus sp. are found in Taiwan waters. Among therotifers, six strains have been isolated and cultured.Another L-type strain and two SS-type strains wereobtained from foreign sources. The cladoceran Diaphanosoma aspinosum and copepod Apocyclopsroyi are the most common species used in aquaculture.Studies of live foods including their morphology,culture techniques, fatty acid composition andnutritional value as feeds have been undertaken.     

Characterisation of Pseudomonas aeruginosa isolated from freshwater culture systems

Members of the genus Pseudomonas are important phytopathogens and agents of human infections, while other strains and species exhibit bioremediation and biocontrol activities. Species-specific detection of Pseudomonas species in the environment may help to gain a more complete understanding of the ecological significance of these microorganisms. The objective of present study was comparative analysis of biochemically and PCR based confirmed 10 isolates of Pseudomonas aeruginosa (6 from fish intestine and 4 from pond sediment). PCR-ribotyping and PAGE revealed that there was extensive heterogeneity at the genetic and protein levels. Both genetic and phenotypic heterogeneity were more in the sediment isolates compared to the fish isolates. SDS-PAGE clearly demonstrated the differences between fish and sediment isolates as evident from the higher range of protein profiling. In antibiotic sentivity test no habitat specific antibiogram was obtained. Zinc adversely affected the DNA of all the isolates to be amplified by PCR as DNA banding pattern was different from normal DNA in stressed DNA. Thus stress, particularly, zinc may interfere monitoring of Pseudomonas by PCR.     

Laboratory culture of submersed freshwater macrophytes on natural sediments

Recent information on the relative roles of sediment and water as nutrient sources for rooted submersed freshwater macrophytes has facilitated the development of methods for culturing these plants. The use of natural sediments rather than culture solutions as the source of nitrogen, phosphorus and micronutrients largely prevents the occurrence of algal blooms and, for many purposes, obviates the need for axenic cultures.Growth requirements of submersed macrophytes are reviewed with regard to the provision of suitable culture conditions. Sediment substrate requirements are considered in relation to the role of sediment as a nutrient source. Two types of culture solution formulations are provided with procedures for establishing and maintaining submersed macrophyte cultures for experimental research.     

Collection of tissue and culture samples from the canine reproductive tract

Definitive diagnosis of reproductive tract infection or other disease often requires sampling of tissue, either for culture or histopathology. Indications, sample collection technique, possible side-effects and interpretation of results are reviewed. Pertinent facts include: (1) collection of uterine biopsy specimens via laparotomy was associated with higher yield of diagnostic samples and fewer side-effects than other less invasive techniques; (2) vaginal culture samples should be collected from the anterior vagina to minimize number of contaminants in the sample; (3) collection of culture samples from the anterior vagina during proestrus or estrus, in the presence of discharge originating in the uterus, was a non-invasive technique for assessment for uterine infection; (4) samples for bacterial culture from mucosal surfaces, including the vagina and penis, must be quantitated to allow interpretation, with moderate to heavy growth of any single aerobic bacterial organism relevant; (5) mycoplasma and ureaplasma are part of the normal flora of the genitourinary tract in dogs and bitches and, because most laboratories cannot give reliable quantitative results, interpretation of positive results often is difficult; (6) collection of prostatic tissue samples for cytology or culture was more likely to yield a correct diagnosis than submission of ejaculated prostatic fluid.     

Interactions between freshwater bacteria andAnkistrodesmus braunii in batch and continuous culture

Batch and continuous cultures ofAnkistrodesmus braunii were established in an inorganic medium with growth rate limited by P. In batch culture, inoculation of lake water bacterial isolates ofPseudomonas sp. andFlavobacterium sp. showed that thePseudomonas isolate was capable of more rapid growth on algal exudates of lytic products than was theFlavobacterium isolate. When inoculated singly into a continuous culture (D=0.267 day^–1; P level, 2M), theFlavobacterium isolate initially caused a decrease in the population density of the alga, but then steady states for both organisms were obtained. ThePseudomonas isolate under the same conditions caused a rapid washout of the algal culture, and steady-state conditions were never obtained. When thePseudomonas isolate was added to the two-member, steady-state system ofA. braunii andFlavobacterium, the algal population again washed out of the vessel, followed by theFlavobacterium and then thePseudomonas isolate. A transient increase in the P concentration to 200M in the culture vessel caused the low algal population level to increase, followed by increases in the bacterial isolates when the algal population was high enough to supply the required organic carbon source. The system demonstrated that competition for P between the alga and the bacteria can occur, and the results were dependent on the algal and bacterial relative growth rates. The bacterial growth rates were limited initially by organic substrates produced by the alga, and the different bacterial isolates competed for these substrates.     

High density culture of the freshwater rotifer,Brachionus calyciflorus

The freshwater rotifer, Brachionus calyciflorus is one of the live food organisms used for the mass production of larval fish. In this study possibility of obtaining high density cultures of the freshwater rotifer B. calyciflorus were investigated. The two culture systems used differed in their air and dissolved oxygen supplies using three temperatures in each case: 24, 28 and 32 °C. Rotifers were batch-cultured using 5 l-vessels and fed with the freshwater Chlorella. The growth rate of rotifers significantly increased with an increase in temperature. The maximum density of the rotifers with air-supply at 24 °C, 6500 ind. ml^–1, was significantly lower than those cultured at 28 and 32 °C, i.e. 8600 and 8100 ind. ml^–1, respectively. Dissolved oxygen levels decreased with time and ranged from 0.8 to 1.4 mg l^–1 when the density of freshwater rotifer was the highest at each temperature. The highest density (19200 ind. ml^–1) of freshwater rotifer was obtained in cultures with a supply of oxygen at 28 °C. Densities of 13500 and 17200 ind. ml^–1 were found at 24 and 32 °C, respectively. Levels of NH₃-N increased with time and a dramatic increase of NH₃-N was observed at high temperatures. Levels of NH₃-N at 24, 28 and 32 °C were 13.2, 18.5 and 24.5 mg l^–1, respectively. These levels coincided with the highest rotifer density at each of the three temperatures. When rotifers were cultured with an oxygen-supply and pH was adjusted to 7, the maximum density of rotifer reached 33500 ind. ml^–1 at 32 °C . These results suggested that high density culture of freshwater rotifer, B. calyciflorus could be achieved under optimal conditions with DO value of exceeding 5 mg l^–1 and NH₃-N values of lower than 12.0 mg l^–1.     

COMBO: a defined freshwater culture medium for algae and zooplankton

In order to conduct experiments on interactions between animals and food organisms, it is necessary to develop a medium that adequately supports the growth of both algae and zooplankton without the need to alter the medium to accommodate either the algae or the animals. We devised a freshwater medium, named COMBO, that supports excellent growth of both algae and zooplankton. Two types of algae, Ankistrodesmus falcatus and Stephanodiscus hantzschii, were reared in COMBO and their growth rates were not significantly different from those of algae grown in a reference medium (WC). One of these algae, A. falcatus, was then fed to a cladoceran, Daphnia pulicaria, which was also cultured in COMBO, and the resulting fecundities of D. pulicaria were compared to those of animals reared in natural surface water. We also determined whether the value of COMBO as a medium for D. pulicaria was affected by modifications in nitrogen or phosphorus concentration to evaluate whether the new medium will be useful in nutritional research. Lowering the N or P content of COMBO did not affect the reproductive performance of D. pulicaria. Other researchers have also reported excellent growth and reproduction by numerous algae and zooplankton reared in COMBO. Our results suggest that COMBO is an effective artificial, defined culture medium capable of supporting robust growth and reproduction of both freshwater algae and zooplankton. This revised version was published online in July 2006 with corrections to the Cover Date.