不同食物浓度下热带地区大型溞属枝角类(Daphnia sinensis和D.galeata)生长和繁殖比较  

Growth and reproduction of two Daphnia species(D. sinensis and D. galeata) in tropics at five levels of food concentrations

作　　者：黄小芳 张晓莉[1] Franja Pajk 韩博平[1] 

机构地区：[1]暨南大学水生生物研究中心,广州51063

出　　处：《应用与环境生物学报》2017年第6期1148-1153,共6页Chinese Journal of Applied and Environmental Biology

基　　金：国家重点基础研发计划(2012CB956100);广东省科技计划项目(2013B080500022)联合资助~~

摘　　要：球藻为两种枝角类的食物,在25℃下设置5个食物浓度梯度(以C计),即0.3、0.5、1.0、1.5、2.0 mg/L.中华溞的首次怀卵体长、首次产后代数目、累积产后代数目、平均寿命、世代时间和净生殖率在5个食物浓度下均显著高于盔形溞,繁殖前历时在5个食物浓度下均显著短于盔形溞.盔形溞的内禀增长率在食物浓度为1.5 mg/L时高于中华溞,个体增长率在食物浓度为0.5和2.0 mg/L时高于中华溞.盔形溞的净生殖率和内禀增长率均随着食物浓度的增加而显著逐步增加;中华溞在食物浓度由1.0 mg/L增加到1.5 mg/L时净生殖率和内禀增长率没有显著性增加,但是其个体增长率极显著增加.中华溞的食物浓度阈值为0.214 mg/L,小于盔形溞的食物浓度阈值0.262 mg/L.在所设置实验条件中,无论在生殖发育还是在食物浓度阈值上中华溞均表现出一定的优势,但是这个结果与野外调查不相符;导致这种差异的原因与它们对生境适应的繁殖策略不同以及热带鱼类的强捕食压力有关,但需要进一步的野外实验验证.In order to compare the effects of food concentration on growth and reproduction and threshold food concentration of two species, Daphnia sinensis and D. galeata, in tropical waters, we conducted a feeding experiment with a flow-through system first used by Lampert. The experimental animals were fed at 25 ℃ with Chlorella pyrenoidosa as food at five organic carbon concentrations （0.3, 0.5, 1.0, 1.5, or 2.0 mg/L）. At all food concentrations, the body length at maturity, the offspring in the first generation, the cumulative number of offspring per female, lifespan, generation time, and the net reproductive rate of D. sinensis were all significantly higher than those of D. galeata. The time to maturity was significantly shorter for D. sinensis than for D. galeata but at the 1.5 mg/L food concentration, the intrinsic rate of the increase was higher for D. galeata than for D. sinensis. At the concentrations 0.5 and 2.0 mg/L, the somatic growth rate was also higher for D. galeata than for D. sinensis. The threshold food concentration of D. sinensis for growth was ~0.214 mg/L, lower than that of D. galeata （0.262 mg/L）. Our experiment demonstrated that D. sinensis has growth and reproductive advantages over D. galeata under the culture conditions, but D. galeata always dominated in large and deep water bodies. The two species appear to adopt different life history strategies in natural water, and their abundance may be mainly regulated by predation pressure in tropics where fish density and diversity are high for all seasons. However, the exact cause needs further investigation via field manipulation.

关 键 词：热带水体 生殖发育 食物浓度阈值 枝角类 

分 类 号：Q958.8[生物学—动物学]