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1.
以浓度分别为 3 0× 10 6、 6 0× 10 6、 9 0× 10 6和 12 0× 10 6cells/mL蛋白核小球藻 (Chlorellapyrenoi dosa)为食物 ,在温度为 (2 5± 1)℃下 ,应用群体累积培养法研究了食物浓度对分布于长江、珠江和淮河水系的 3个地理品系的角突臂尾轮虫 (Brachionusangularis)种群的增长、个体和卵的体积的影响。结果表明 ,食物浓度、地理品系及两者间的交互作用对轮虫种群增长率、个体和卵的体积均有显著影响。同一食物浓度下 ,广州品系的种群增长率最大 ,芜湖品系的个体和卵体积最大 ;同一品系中 ,当食物浓度为 9 0× 10 6cells/mL时轮虫有较大的种群增长率。各品系轮虫的种群增长率与食物浓度均呈曲线相关 ,但种群增长率达最大时所需的食物浓度在各品系间存在着差异。在食物浓度和品系两因素中 ,品系对轮虫个体体积有较大的影响  相似文献   

2.
温度和食物浓度对三品系萼花臂尾轮虫实验种群动态的影响   总被引:15,自引:5,他引:10  
应用个体培养方法,研究了温度(20、25和30℃)和藻类食物浓度(1.5×10^6、3.0×10^6、6.0×10^6和9.0×10^6cells·ml^-1)对青岛、芜湖、广州三品系萼花臂尾轮虫种群动态的影响.结果表明,温度仅对轮虫的世代时间和种群内禀增长率有显著影响,而品系对所有生命表参数均无显著影响.轮虫种群的内禀增长率随培养温度的升高而增大,世代时间则随培养温度的升高而缩短.食物浓度仅对轮虫的生命期望值和平均寿命有显著影响,品系对轮虫的净生殖率、世代时间、生命期望值和平均寿命也有显著影响.三品系间,以广州品系轮虫的净生殖率、世代时间、生命期望值和平均寿命最大,芜湖品系最短.当食物浓度为3.0×10^6cells·ml^-1时,轮虫的生命期望值和平均寿命最长,9.0×10^6cells·ml^-1时最短.各品系轮虫的净生殖率、世代时间、总生殖率、生命期望值和平均寿命均随培养温度的升高而减小,广州品系的净生殖率除外.轮虫种群的内禀增长率和广州品系轮虫的总生殖率则随培养温度的升高而增大.青岛和广州品系轮虫的各生命表参数,均与食物浓度呈曲线相关,但芜湖品系仅世代时间、平均寿命和生命期望值随食物浓度的增大而缩短.  相似文献   

3.
采用群体累积培养法,研究了藻类食物的种类和浓度对红臂尾轮虫种群增长、个体大小及卵大小的影响.结果表明,藻种类和浓度对红臂尾轮虫种群增长率、个体体积及卵体积均有极显著影响.不同食堕种空中,种群增长率以小球藻组最小,栅藻组最大;个体体积以小球藻组最小,栅藻组和混合藻组问无显著差异.种群增长率(Y,d^-1)与食物浓度(X,×10^6cells·ml^-1)间呈曲线相关,两者间的关系符合方程:y=-0.0040x^2+0.0409X+0.4471。在所研究的食物浓度范围内,当浓度分别高于或低于6.0×10^cells·m1^-1和3.0×10^6cells·ml^-1时,轮虫个体体积和卵体积均分别呈减小的趋势。  相似文献   

4.
应用单个体培养方法,以浓度为3.0×106 cells·ml-1的斜生栅藻为食物,在18 ℃、23 ℃、28 ℃和33 ℃的温度梯度下比较了镰形臂尾轮虫和尾突尾轮虫的生活史特征.结果表明:18 ℃和23 ℃下,尾突臂尾轮虫的生殖期和平均寿命均显著长于镰形臂尾轮虫,产卵量也显著大于镰形臂尾轮虫;28 ℃下,2种轮虫的各主要发育阶段历时、平均寿命和产卵量均无显著差异;33 ℃下,镰形臂尾轮虫的生殖期和生殖后期历时以及平均寿命均显著长于尾突臂尾轮虫,产卵量显著大于尾突臂尾轮虫.18 ℃下,尾突臂尾轮虫的生命期望、净生殖率和种群内禀增长率均显著大于镰形臂尾轮虫;23 ℃和28 ℃下,尾突臂尾轮虫的生命期望显著长于镰形臂尾轮虫,而其他种群增长参数间均无显著差异;33 ℃下,镰形臂尾轮虫的世代时间、生命期望、净生殖率和种群内禀增长率均极显著大于尾突臂尾轮虫.2种轮虫的主要发育阶段历时、平均寿命、产卵量、世代时间、生命期望、净生殖率和种群内禀增长率对温度变化的反应也存在差异.研究结果表明,尾突臂尾轮虫更能适应较低的环境温度,而镰形臂尾轮虫则相反.  相似文献   

5.
长江口疏浚弃土悬沙对褶皱臂尾轮虫的影响   总被引:13,自引:0,他引:13  
采用克隆培养法 (编制生命表 )和群体累积培养法 ,研究了长江口疏浚弃土悬沙对褶皱臂尾轮虫(Brachionusplicatilis)的影响 .实验设 0 (CK)、1、3、5、7、9mg·ml-16个悬沙梯度和 2 0、12× 10 6cells·ml-1两个饵料密度 .结果表明 ,克隆培养时 ,悬沙可使该轮虫种群的内禀增长率 (rm)下降 2 9.6 %~ 6 4 .1% ,最大降幅为 130 .0 % .悬沙对轮虫种群的存活率 (lx)有影响 ,而对种群的繁殖率 (mx)无显著影响 .群体累积培养时 ,悬沙对轮虫种群的雌体密度、雄体密度、孤雌生殖卵和休眠卵的密度以及种群的动态变化规律无显著影响 .可见 ,长江口疏浚工程会对轮虫动物有一定的负面影响  相似文献   

6.
对镜湖萼花臂尾轮虫(Brachionus calyciflorus)夏季种群内4个生化遗传特征上互不相同的克隆(克隆A、B、C和D)在4个斜生栅藻(Scenedesmus obliquus)密度(1.0×106、2.0×106、4.0×106和8.0×106 cells·L-1)下的生活史特征进行了研究.结果表明:食物密度对各克隆轮虫的存活率和繁殖率均有不同的影响.4克隆中克隆C的世代时间最短,克隆B的世代时间、生命期望和平均寿命最长,克隆A的后代混交雌体百分率最高;净生殖率和个体适合度在4克隆间无显著差异.镜湖萼花臂尾轮虫在2.0×106 cells·L-1的食物密度下净生殖率最低;在1.0×106cells·L-1的食物密度下平均寿命和生命期望最短,而后代混交雌体百分率却最高;在8.0×106cells·L-1的食物密度下种群内禀增长率最高,平均寿命和生命期望最长;在高食物密度(4.0、8.0×106cells·L-1)下个体适合度较大.克隆C的个体适合度在密度为3.9×106cells·L-1时最小,而克隆D的个体适合度在食物密度为6.34×106cells·L-1时最大.食物密度的变化可能是7月份之后镜湖萼花臂尾轮虫从水环境中消失的原因,而4克隆轮虫个体适合度的相似性则可能是镜湖轮虫共存于同一水体的原因之一.  相似文献   

7.
温新利  席贻龙 《生态学报》2007,27(10):3956-3963
对镜湖臂尾轮虫种群的周年动态进行了研究,测量和分析了它们的个体大小、卵大小和相对卵大小及其与水温和叶绿素a浓度等生态因子间的关系。结果表明,镜湖常见的7种臂尾轮虫中,仅萼花臂尾轮虫(Brachionus calyciflorus)、角突臂尾轮虫(B.angularis)、裂足臂尾轮虫(B.diversicornis)和剪形臂尾轮虫(B.forficula)的种群密度和出现频率较高;前两者种群密度高峰期均出现在2~3月份,4月份后均较低;后两者种群密度在6~9月份较高,而在10月份后很快下降。除剪形臂尾轮虫外,其它3种臂尾轮虫的个体体积均与水温间具有显著的相关性,平均卵体积均与各自的平均被甲长度呈显著的正相关关系。角突臂尾轮虫和萼花臂尾轮虫个体大小与水体叶绿素a浓度间呈显著的负相关关系,它们的卵体积分别与水温和叶绿素a浓度之间具有显著的负相关性,且水温是影响它们卵体积的主要因子。4种臂尾轮虫中,仅角突臂尾轮虫的相对卵体积与水温间表现出显著的正相关关系。  相似文献   

8.
温度对三品系角突臂尾轮虫生活史策略的影响   总被引:15,自引:5,他引:10  
应用群体累积培养法 ,以浓度为 6 .0× 10 6cells/mL蛋白核小球藻 (Chlorellapyrenoidosa)为食物 ,研究了温度(2 0℃、2 5℃和 30℃ )对青岛、广州与芜湖等品系的角突臂尾轮虫 (BrachionusangularisGosse)的种群增长、个体大小和卵大小的影响。结果表明 ,温度对各品系轮虫的种群增长率和个体大小等均有显著影响。青岛品系和广州品系轮虫种群增长的最适温度分别为 30℃和 2 5℃ ,芜湖品系轮虫则在 30℃下不能生存。青岛品系和广州品系的种群增长率均与温度呈曲线相关 ,回归方程分别为 :Y =0 .0 0 0 9X2 - 0 .0 0 6 1X 0 .4 0 90和Y =- 0 .0 14 4X2 0 .74 12X - 8.375 1。各品系轮虫个体大小和卵大小均随温度的升高而呈现出下降趋势。在本研究的温度范围内 ,广州、青岛和芜湖各品系轮虫个体变异分别达 4 2 .90 %、14 .4 3%和 6 .2 3% ;2 0℃和 2 5℃下芜湖品系分别高出青岛品系达 74 .91%和87.98%。在温度和品系两因素中 ,品系对轮虫个体体积有较大的影响  相似文献   

9.
对采自青岛和芜湖两地的萼花臂尾轮虫在3种温度(20 ℃、25 ℃和30 ℃)和2种藻类食物浓度(1.0×106和5.0×106 cells·ml-1)下所产休眠卵的长径、短径和体积等形态特征进行了显微测量、计算和分析.结果表明,2种食物浓度下,培养温度以及培养温度和品系间的交互作用均对轮虫休眠卵的长径、短径和体积具有显著影响.当食物浓度分别为1.0×106和5.0×106 cells·ml-1时,轮虫在20 ℃下所产休眠卵的长径、短径和体积均最大;在25 ℃和30 ℃下所产休眠卵的短径和体积均最小.品系对轮虫休眠卵长径、短径和体积的影响也取决于食物浓度.当食物浓度为1.0×106 cells·ml-1时,芜湖品系轮虫的休眠卵长径、短径和体积(156.00 μm、99.95 μm和12 269.11 μm3)均显著大于青岛品系轮虫的休眠卵(145.13 μm、91.97 μm和10 498.19 μm3);而当食物浓度为5.0×106 cells·ml-1时,芜湖品系轮虫的休眠卵长径、短径和体积(155.68 μm、100.85 μm和12 348.59 μm3)均与青岛品系轮虫的休眠卵(156.63 μm、98.04 μm和12 054.20 μm3)之间无显著差异.两品系中,仅芜湖品系轮虫休眠卵的长径、短径和体积分别与温度呈曲线相关.同一温度下,两品系轮虫的休眠卵体积均随着食物浓度升高而增大;但30 ℃下芜湖品系轮虫所产休眠卵体积却随着食物浓度的升高而减小.  相似文献   

10.
以浓度分别为1.0×106、2.0×106、4.0×106和8.0×106cells·mL-1的斜生栅藻(Scenedesmus obliquus)为轮虫食物,在25℃下,应用群体累积培养和单个体培养法研究了食物浓度对采自新安江水域(屯溪段)的萼花臂尾轮虫的种群动态影响。结果表明:食物浓度对轮虫的种群增长率和休眠卵产量均有显著的影响,均表现为低食物浓度下(≤4.0×106cells·mL-1)萼花臂尾轮虫的种群增长率和休眠卵产量较小且无差异,高食物浓度下(8.0×106cells·mL-1)轮虫的种群增长率和休眠卵产量较大;食物浓度对轮虫的混交雌体百分率和受精率无显著影响;在食物浓度为4.0×106cells·mL-1时萼花臂尾轮虫的净生殖率最大,世代时间最长,而其内禀增长率在食物浓度为1.0×106cells·mL-1时最小;在食物浓度为8.0×106cells·mL-1时平均寿命和生命期望最长。  相似文献   

11.
The rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 106 cells ml−1). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed on higher densities of Chlorella sp. (10 × 106 cells ml−1) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 106 cells ml−1). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size.  相似文献   

12.
We compared the population growth of B. calyciflorus and B. patulus using the green alga Chlorella vulgaris, baker's yeast Saccharomyces cerevisiae or their mixture in equal proportions as food. Food was offered once every 24 h in two concentrations (low: 1 x 10(6) and high: 3 x 10(6) cells ml-1) separately for each species. The experiments were terminated after 15 days. In general, at any food type or concentration, B. patulus reached a higher population density. A diet of Chlorella alone supported a higher population growth of both rotifer species than yeast alone. B. calyciflorus and B. patulus achieved highest population densities (103 +/- 8 ind. ml-1 and 296 +/- 20 ind. ml-1, respectively) on a diet of Chlorella at 3 x 10(6) cells ml-1. When cultured using the mixture of Chlorella and yeast, the maximal population densities of B. calyciflorus were lower than those grown on Chlorella. Under similar conditions, the maximal abundance values of B. patulus were comparable in both food types. Regardless of food type and density the rate of population increase per day (r) for B. calyciflorus varied from 0.13 +/- 0.03 to 0.63 +/- 0.04. These values for B. patulus ranged from 0.19 +/- 0.01 to 0.37 +/- 0.01. The results indicated that even though Chlorella was a superior food for the tested rotifers, yeast can be effectively used at low concentrations to supplement algal requirements in rotifer culture systems.  相似文献   

13.
三个品系角突臂尾轮虫生长和发育的比较研究   总被引:5,自引:5,他引:0  
以浓度为2.4×10^6cells.ml^-1的斜生栅藻为食物,在25℃下,对采自青岛、广州与芜湖等品系的角突臂尾轮虫的胚胎发育、生殖前期和最小世代时间等个体发育阶段历时以及幼体和成体的个体大小、卵体积和相对卵体积进行了研究.结果表明,轮虫的胚胎发育时间、生殖前期历时和最小世代时间等在品系间均存在显著差异.芜湖品系具有最长的胚胎发育时间,其次为广州品系和青岛品系;青岛品系的生殖前期最长,广州品系最短;而最小世代时间以广州品系最小,青岛品系和芜湖品系次之,后两者之间无显著差异.各品系轮虫胚胎发育时间具有随其相对卵体积的增大而缩短的趋势.同一年龄段各品系间的轮虫幼体体积均有显著差异,且均以芜湖品系为最大.三品系轮虫个体幼体体积与其年龄间均呈曲线相关;刚孵化出的幼体体积与其成体间差异在芜湖品系达244.24%,青岛和广州品系分别为182.89%和156.28%.轮虫成体的个体大小、卵大小和相对卵大小在品系间也存在显著差异.  相似文献   

14.
In order to maintain rotifer populations during periods of low algal production, it is necessary to offer alternate diets, some of which include forms of preserved algae. The present work is based on the effect of live and dead Chlorella vulgaris on the population growth of Brachionus calyciflorus and Brachionus patulus. The experimental design consisted of three algal levels (0.5 x 10(6), 1.5 x 10(6) and 4.5 x 10(6) cells ml-1) offered in three forms (living, frozen and heat-killed). The maximal population density values for B. calyciflorus ranged from 55 +/- 1 ind. ml-1 (at 0.5 x 10(6) cells ml-1) to 471 +/- 72 ind. ml-1 (at 4.5 x 10(6) cells ml-1) with live Chlorella, but was much lower (6 +/- 1 to 26 +/- 6 ind. ml-1) with frozen or heat-killed alga under comparable food levels. However, the maximum population density of B. patulus under live or or heat-killed Chlorella was similar at comparable algal levels but when offered frozen algae it was four times less. The highest mean peak population density was 1,277 +/- 83 ind. ml-1 under 4.5 x 10(6) cells ml-1. The rate of population increase for B. calyciflorus varied from 0.50 to 0.79 using live Chlorella, but under comparable conditions, this range was lower (0.21 to 0.31) for B. patulus. Results have been discussed in light of possible application for aquaculture.  相似文献   

15.
以萼花臂尾轮虫(Brachionus calyciflorus)为受试动物,研究了不同浓度(400、800和1 200 mg/L)的三聚氰胺对萼花臂尾轮虫种群增长、有性生殖、个体大小和卵大小的影响.结果显示,三聚氰胺对萼花臂尾轮虫的24 h LC50值为2 627.00 mg/L.与空白对照组相比,800和1 200 ...  相似文献   

16.
1. The egg size of insects can vary depending on maternal body size or resource status, and it may influence offspring body size by determining initial resource level. 2. The giant rhinoceros beetle Trypoxylus dichotomus exhibits considerable variation in body size, some of which is attributed to the variation in larval food (humus) quality, although a substantial amount of variation in body size remains unexplained. In the present study, changes in the egg size and offspring body size in response to several maternal variables were examined (i.e. body size, age, and, nutritional status). 3. Nutritional intake of the females during the adult stage did not affect the egg size. Larvae hatched from small eggs partially recovered from the initial disadvantage during their ontogenetic processes by increasing growth rate (i.e. compensatory growth); however, there was still a positive relationship between egg size and pupal body size. 4. Older females produced small eggs, but because of compensatory growth, the pupae were no longer small. By contrast, due to a lack of compensatory growth, small females produced small eggs as well as small pupae. 5. These results suggest that maternal body size affects offspring body size through effects on egg size. This transgenerational effect may account for some of the variation in adult body size of T. dichotomus.  相似文献   

17.
Salinity is an important variable influencing the density and diversity of rotifers. Studies on salt tolerance of rotifers have so far concentrated on euryhaline species while very little information is available on non-euryhaline taxa. In the present work, we have evaluated the combined effects of Chlorella vulgaris and sodium chloride on the population growth of two freshwater rotifers B. calyciflorus and B. patulus. A 24 hr acute tolerance test using NaCl revealed that B. calyciflorus was more resistant (LC50 = 3.75 +/- 0.04 g l-1) than B. patulus (2.14 +/- 0.09 g l-1). The maximal population density (mean +/- standard error) for B. calyciflorus in the control at 4.5 x 10(6) cells ml-1 (algal level) was 80 +/- 5 ind. ml-1, which was nearly a fifth of the one for B. patulus (397 +/- 7 ind. ml-1) under comparable conditions. Data on population growth revealed that regardless of salt concentration, the density of B. calyciflorus increased with increasing food levels, while for B. patulus, this trend was evident only in the controls. Regardless of salt concentration and algal food level, the day of maximal population density was lower (4 +/- 0.5 days) for B. calyciflorus than for B. patulus (11 +/- 1 day). The highest rates of population increase (r values) for B. calyciflorus and B. patulus were 0.429 +/- 0.012 and 0.367 +/- 0.004, respectively, recorded at 4.5 x 10(6) cells ml-1 of Chlorella in the controls. The protective role of algae in reducing the effect of salt stress was more evident in B. calyciflorus than B. patulus.  相似文献   

18.
The paper describes the relationships between adult age, hatching date, egg volume, brood size, hatching sequence, chick weight at hatching, chick growth rate and chick body size for a population of Great skuas in Shetland. The relative importance of these factors, and food availability, is assessed in determining chick size, weight, and growth rate.  相似文献   

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