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

应用个体培养方法,研究了温度(20、2和30 ℃)和藻类食物浓度(1.5×10₆、3.0×10₆、6.0×10₆和9.0×10₆ cells·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3.0×10₆ cells·ml^-1时,轮虫的生命期望值和平均寿命最长,9.0×10₆ cells·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.     

不同品系萼花臂尾轮虫休眠卵的形态特征

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.     

营养强化时褶皱臂尾轮虫对饵料微藻的摄食

选取适宜浓度利用单种微藻和混合微藻对轮虫进行营养强化,采用实验生态学方法研究了轮虫滤水率和摄食率的动态变化.结果表明:微藻浓度、微藻种类和培养时间均对轮虫的滤水率和摄食率有显著影响;轮虫对几种单种微藻的滤水率和摄食率均随培养时间的延长而下降,在实验条件下,6h内轮虫对3种微藻的滤水率大小顺序为小球藻＞球等鞭金藻＞牟氏角毛藻,12h内轮虫对3种和,微藻的滤水率大小顺序则为球等鞭金藻＞小球藻＞牟氏角毛藻;轮虫在混合微藻中的选择顺序为球等鞭金藻＞小球藻＞牟氏角毛藻.     

光照对蒙古裸腹溞摄食强度的影响

利用细胞计数法对不同光照强度、光谱成分、光周期对蒙古裸腹摄食强度的影响进行了研究。结果表明 :光强在 70 0 0 lx时蒙古裸腹对小球藻的摄食强度最高 ,成的滤水率和摄食率分别为 0 .5 2 8± 0 .0 0 9ml/ (ind· h)和 1.113± 0 .0 15μg C/ (ind· h) ,幼的滤水率分别为 0 .4 95± 0 .0 14 ml/ (ind· h)和 1.0 5 1± 0 .0 0 8μg C/ (ind· h)。在蓝光下蒙古裸腹对小球藻的摄食强度明显高于绿光组。光周期 L∶ D为 12∶ 12时蒙古裸腹对小球藻的摄食强度最高 ,成和幼的滤水率分别为0 .4 6 1和 0 .35 5 ml/ (ind· h) ,摄食率分别为 1.2 4 2和 1.0 0 5μg C/ (ind· h) ,而在 L∶ D为 0 :2 4时摄食强度最差 ,成和幼的滤水率分别为 0 .0 70和 0 .0 5 0 ml/ (ind· h)。在自然光照下 ,蒙古裸腹对小球藻的摄食强度在 7∶ 0 0～ 11:0 0和 15 :0 0～ 19:0 0最高     

食物浓度和品系对萼花臂尾轮虫生殖期历时和混交雌体形成的影响

应用单个体培养方法比较研究了藻类食物浓度(2.0、5.0、8.0和11.0×106cells/mL)和品系对采自广州、青岛和芜湖等地的萼花臂尾轮虫生殖期历时、后代数和后代中混交雌体百分率的影响。结果表明,食物浓度对轮虫的生殖期历时和轮虫全部后代中的混交雌体百分率有显著的影响,但对轮虫的总后代数无显著的影响。品系对轮虫的生殖期历时、总后代数和全部后代中的混交雌体百分率均有显著影响。3品系间,广州品系轮虫的生殖期历时最长,为(4.53±0.19)d;总后代数最多达(18.75±0.26)个;全部后代中的混交雌体百分率最低,仅为4.32%±0.51%。而青岛品系轮虫全部后代中的混交雌体百分率最高,达49.90%±2.15%;其生殖期历时和总后代数与芜湖品系间均无显著的差异。食物浓度和品系间的交互作用仅对轮虫全部后代中的混交雌体百分率有显著影响。3品系中,仅芜湖品系轮虫的生殖期历时、总后代数和全部后代中的混交雌体百分率受食物浓度的显著影响;母体年龄对轮虫每天所产后代中的混交雌体百分率的影响因轮虫品系的不同和培养时所用的食物浓度的不同而异。     

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

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．     

流溪河水库中瘤棘砂壳虫的摄食食物种类研究

有壳变形虫是一些单细胞的,异养的,自由生活的,生活在由有机颗粒,石英啥,硅质的矿物质等以规则的顺序组成的外壳中的原生动物^[1],广泛分布于世界各地^[2],水生砂壳虫是其典型代表^[3]。据报道砂壳虫摄食水中的微小颗粒以及轮虫,甚至是大型的浮游生物^[4]。因而砂壳虫可能是水体中连接经典食物链和微型食物链的关键浮游生物。为了系统地研究砂壳虫的摄食行为的特点,在流溪河水库水体中进行了两年的野外监测并结合室内活体观察。瘤棘砂壳虫最初发现于贵州,杨军等人于2004年重新描述了该种类并给予系统地形态学和壳元素组成研究^[5],是流溪河水库该属的一个优势种类。瘤棘砂壳在流溪河水库中于晚春出现,秋季消失,种群在夏季达到峰值。据活体观察,该种类属肉食性,其摄食浮游生物主要是轮虫,包括胶鞘轮虫,独角聚花轮虫(个体),螺形龟甲轮虫,红多肢轮虫(死亡个体),奇异六腕轮虫(死亡个体),对棘异尾轮虫(死亡个体),以及无节幼体(死亡个体)。瘤棘砂壳虫2006年出现于5月~10月,丰度范围为1.2~25.88ind.·L^-1,2007年丰度范围为0.2~11.2 ind.·L^-1。螺形龟甲轮虫和红多肢轮虫的丰度范围分别为0.2~101.2ind.·L^-1,0.1~45.71ind.·L^-1。胶鞘轮虫和独角聚花轮虫的丰度范围分别为0.02~11.4ind.·L^-1,0~26 ind.·L^-1,并且都是在夏季达到峰值。胶鞘轮虫和独角聚花轮虫由于身体柔软、游泳速度不快,是易被瘤棘砂壳虫摄食的轮虫。独角聚花轮虫在自然水体中有集群行为,能够抵御肉食动物的捕食,因为在自然水体中被摄食的几率较小。而其它的轮虫如龟甲轮虫,红多肢轮虫,由于外壳硬,游泳速度快,瘤棘砂壳虫对它们的捕食成功率很低。瘤棘砂壳虫主要依靠伪足进行摄食活动和爬行,其摄食行为和机制应该得到进一步的研究。     

不同饵料密度和盐度下褶皱臂尾轮虫的生活史特征

为探索低盐驯化褶皱臂尾轮虫规模化培育的可行性,本实验以小球藻(Chlorella vulgaris)为饵料,在饵料密度1.0×10⁴、1.0×10⁵、1.0×10⁶、1.0×10⁷和1.0×10⁸ cells·mL^-1下,采用单个体培养法,研究了盐度23及盐度6的褶皱臂尾轮虫(Brachionus plicatilis)的生活史特征。结果表明：随着饵料密度的升高,两组盐度轮虫的生殖期、平均寿命、产卵量、生命期望、净生殖率、世代时间和种群内禀增长率均呈现出先升高再降低(P<0.05);盐度6的轮虫在饵料密度1.0×10⁶、1.0×10⁷和1.0×10⁸ cells·mL^-1下的生殖前期显著小于饵料密度1.0×10⁴和1.0×10⁵ cells·mL^-1下的生殖前期(P<0.05);盐度23的轮虫...     

温度对三品系角突臂尾轮虫生活史策略的影响

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     

温度、盐度和食物条件对西藏拟溞摄食强度的影响

报道了不同温度、盐度和饵料条件下西藏拟溞的摄食强度、西藏拟溞对不同饵料生物蛋白核小球藻(Chlorellapyrenoidesa)、牟氏角毛藻(Chaetoceros muelleri)、湛江等鞭金藻(Isochrysis zhanjiangensis)、亚心形扁藻(Platymonas subcordiformis)、盐藻(Dunaliella salina)、新月拟菱形藻(Nitzschiella closterium)的选择性以及摄食节律。结果表明,在适温范围(2 20℃)内,西藏拟溞的滤水率、摄食率随着温度的升高而增加,14 16℃为西藏拟溞的适宜温度。在盐度20时,西藏拟溞的摄食率最高,幼、成溞对等鞭金藻的摄食率分别为1.88 ng C/(ind.h)和3.46 ng C/(ind.h)。西藏拟溞对角毛藻的滤水率和摄食率均随着龄期增加而增加,而对等鞭金藻呈相反趋势,但二者的日粮均随体长增大而减小。幼、成溞的滤水率和摄食率随食物密度变化的趋势基本一致,均是在盐藻密度为1×106 ind./L时均最高,分别为0.194、0.221 mL/(ind.h)和0.030μgC/(ind.h)和0.034μgC/(ind.h)。幼溞对6种藻的食物选择性为角毛藻小球藻盐藻扁藻金藻拟菱形藻;成溞为扁藻角毛藻盐藻金藻小球藻拟菱形藻。幼溞、成溞均对角毛藻和盐藻的选择性较好。西藏拟溞的幼溞和成溞对牟氏角毛藻的摄食有相同的节律,在15:00 17:00和01:00 03:00时有两个摄食高峰,在09:00 11:00和23:00 01:00有两个低谷。     

食物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

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。     

Effect of three food types on the population growth of Brachionus calyciflorus and Brachionus patulus (Rotifera: Brachionidae).

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.     

食物浓度对角突臂尾轮虫种群增长、个体大小和卵大小的影响

以蛋白核小球藻为食物 ,应用群体累积培养法研究了食物浓度对角突臂尾轮虫种群增长、个体大小和卵大小等的影响 .结果表明 ,食物浓度对角突臂尾轮虫种群增长率、个体大小和卵大小均有极显著影响 .其中 ,轮虫种群增长率与食物浓度间呈曲线相关 ;当食物浓度为 8.2 4 5 3× 10 6cells·ml-1时 ,种群增长率达最大值 0 .6 0 85d-1;在所研究的食物浓度范围内 ,轮虫个体具有随食物浓度的增大而增大的趋势 ,轮虫卵体积在中等食物浓度范围 (6 .0× 10 6～ 9.0× 10 6cells·ml-1)时较大     

Effect of different densities of live and dead Chlorella vulgaris on the population growth of rotifers Brachionus calyciflorus and Brachionus patulus (Rotifera)

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.     

Combined effect of concentrations of algal food (Chlorella vulgaris) and salt (sodium chloride) on the population growth of Brachionus calyciflorus and Brachionus patulus (Rotifera)

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.     

三种不同小球藻去除亚硝态氮和氨氮能力的研究

为了研究小球藻在不同质量浓度的氨氮和亚硝态氮环境下的去除能力与生长效果,从实验室挑选3株不同的小球藻CV315-1(Chlorella sp.)、CV315-2(Chlorella sorokiniana)和CV315-3(Chlorella pyrenoidosa)分别置于不同质量浓度的氨氮和亚硝态氮模拟污水中,在温度26℃,光照强度8000 Lux,光暗比为12 h∶12 h的光照培养箱中培养168 h,每隔24 h取样检测模拟污水中氨氮和亚硝态氮的质量浓度和小球藻浓度。实验结果表明:当氨氮浓度4 mg/L时,CV315-1、CV315-2和CV315-3均能在120 h完全去除。当氨氮浓度6 mg/L时,CV315-3能在144 h时完全去除,而CV315-1和CV315-2在168 h时完全去除。并且随着氨氮浓度的升高,三株藻的去除率均逐渐降低,当氨氮浓度10 mg/L时,CV315-1和CV315-3生长速度最快。当亚硝态氮浓度10 mg/L时,CV315-1能在120 h时完全去除,而CV315-2和CV315-3在144 h时完全去除。并且随着亚硝态氮浓度的升高,三株藻的生长速度逐渐升高。研究结果表明:CV315-1、CV315-2和CV315-3均能在不同质量浓度的氨氮和亚硝态氮环境中生长,且具有良好的耐受能力与去除效果,在净化养殖污水方面有着广阔的应用前景。     

Effects of food quality and starvation on the optimal foraging behavior of Daphnia magna (Cladocera)

In the present work, we evaluated the feeding selectivity of starved Daphnia magna on two freshwater green algae Chlamydomonas sajao and Chlorellapyrenoidosa. Compared to C. pyrenoidosa, food quality of C. sajao are better in food palatability (cell size and digestibility), but poor in nutritional content (total carbon content). D. magna was starved for 0 and 8 d, and then was allowed to graze on a mixture of C. sajao and C. pyrenoidosa with following proportion: 5 × 10⁴: 35 × 10⁴ cells ml^?1, 20 × 10⁴: 20 × 10⁴ cells ml^?1 and 35 × 10⁴: 5 × 10⁴ cells ml^?1. The results indicated that the ingestion rate and filtration rate of starved D. magna, comparing with satiated groups, on C. pyrenoidosa increased significantly, while, inverse trends was observed in C. sajao. Base on selectivity coefficient of D. magna, we observed that when D. magna was in satiation C. sajao will be preferred, while, C. pyrenoidosa will be selected when D. magna was in starvation, and moreover, these foraging behaviors were not influenced by the relative food abundance of each green alga. Therefore, a tradeoff between food palatability (physical makeup) and food nutritional content (chemical composition) can be hypothesized in the foraging behavior of D. magna, which is modified by the starvation of feeder. High valuable food is always selected by D. magna as predicted by optimal foraging theory. However, when D. magna is in satiation food diets with adequate size and easy digestibility will be preferred, while, those foods with relatively higher lipid or total carbon content will be selected when D. magna is in starvation.