食物浓度对拟同形溞(Daphnia similoides)生长和繁殖的影响  

Effect of food concentration on the development and reproduction of Daphnia similoides

作　　者：罗晓霞[1] 刘正文[1] 

机构地区：[1]暨南大学生态学系与水生生物研究所,广州510632

出　　处：《生态科学》2014年第2期288-293,共6页Ecological Science

基　　金：NSFC-云南联合基金项目(U1033602)

摘　　要：研究了不同食物(斜生栅藻Scenedesmus obliquus)浓度对拟同形溞(Daphnia similoides)生长繁殖的影响,实验共设7个浓度组(有机碳浓度分别为0.25,0.75,1.5,5.5,11,16,20 mg·L–1)。结果表明拟同形溞的体长、生长率、累积孵化率和内禀增长率mr均随着食物浓度的增加而增加,在最高浓度20 mg C·L–1达到最高值,其体长为3.55 mm,生长率为0.23 d–1,累积孵化率为327.45个/雌,内禀增长率为0.399,显著高于最低浓度0.25 mg C·L–1组(体长为2.52 mm,生长率为0.15 d–1,累积孵化率为20.3个/雌,内禀增长率为0.12)。拟同形溞的产前发育期、存活时间则随着食物浓度的增加而减少,在浓度为1.5—20 mg C·L–1时,拟同形溞的产前发育期为4—5天,之后随着浓度下降,产前发育期延长,0.75 mg C·L–1和0.25 mg C·L–1组的产前发育期分别为6天和7天。食物浓度越低,寿命越长,最低浓度组(0.25 mg C·L–1)的拟同形溞的寿命是62天,是最高组(20 mg C·L–1)的2.5倍。因此,拟同形溞生长与繁殖的适合浓度范围为5.5—20 mg C·L–1。An experiment was carried out in lab to evaluate effects of food concentration on the growth of Daphnia similoides. The animals were fed by Scenedesmus obliquus as food designated with seven organic carbon concentrations, which was 0.25, 0.75, 1.5, 5.5, 11, 16, 20 mg·L-1, respectively. The results showed that different concentrations of S. obliquus had significant effects on the development and reproduction of D. similoides. When the food concentration increased, the body length, growth rate, hatch rate and intrinsic rate of D. similoides would increase accordingly. The body length, growth rate, hatch rate and intrinsic rate at the highest food concentration （20 mg C·L-1） were 3.55 mm, 0.23 d-1, 327.45 neonates per female and 0.399, respectively, which were significantly higher than those of the lowest concentration （0.25 mg C·L-1）. The maturity time of D. similoides was 4-5 days when the food concentration ranged from 5.5 to 20 mg C·L-1, but then the maturity time increased with the decreasing of food concentration.The maturity time of 0.75 mg C·L-1 and 0.25 mg C·L-1 was 6 and 7 days, respectively. The lifespan decreased with the increasing of food concentrations. The lifespan of the lowest concentration group （0.25 mg C·L-1） was 62 days, which was 2.5 times higher than that of the highest concentration group （20mg C·L-1）. Therefore, the most favorable food concentration for the development and reproduction of D.similoides should be ranging from 5.5 mg C·L-1 to 20 mg C·L-1.

关 键 词：食物浓度 拟同形溞 生长率 存活 繁殖 

分 类 号：X171.4[环境科学与工程—环境科学]