Baer K N, Goulden C E
School of Pharmacy, Division of Toxicology, Northeast Louisiana University, Monroe, USA.
Ecotoxicol Environ Saf. 1998 Mar;39(3):201-6. doi: 10.1006/eesa.1997.1627.
A new high-hardness (H-H) COMBO medium for long-term culturing and bioassay testing of Daphnia magna was evaluated in 21-day survival, growth, and reproduction studies. The COMBO medium originally designed for softwater daphnid species (i.e., D. pulicaria) was modified for the hardwater species D. magna. This medium also allowed continuous culturing of a green algal food source for daphnids, Ankistrodesmus falcatus. After 12 generations of culturing in H-H COMBO medium, the mean fecundity was 128 +/- 12 (coefficient of variation = 9.4%). No significant observations of dead young, aborted eggs, or reduced antennas were made during the 6 months of continuous culturing. The no-observable-effect concentration (NOEC) for a reference toxicant standard, 3,4-dichloroaniline (3,4-DCA), was 8.3 micrograms/liter, which is similar to published values. These studies demonstrate that H-H COMBO is an acceptable medium for use for culturing and bioassay testing with D. magna. Additional experiments using frozen aliquots of A. falcatus were conducted. Although mean fecundity (64 +/- 7) and adult length were significantly decreased from the values for daphnids fed fresh algae, the NOEC for 3,4-DCA was > 25 micrograms/liter. The use of this alternative food source in bioassay testing appears promising, but further optimization of feeding rates is warranted.
一种用于大型溞长期培养和生物测定测试的新型高硬度（H-H）COMBO培养基在为期21天的生存、生长和繁殖研究中得到了评估。最初为软水溞类物种（即蚤状溞）设计的COMBO培养基被修改用于硬水物种大型溞。这种培养基还允许持续培养大型溞的绿藻食物源镰形纤维藻。在H-H COMBO培养基中培养12代后，平均繁殖力为128±12（变异系数=9.4%）。在连续培养的6个月期间，未观察到明显的幼体死亡、卵流产或触角缩短现象。参考毒物标准3,4-二氯苯胺（3,4-DCA）的无可见效应浓度（NOEC）为8.3微克/升，这与已发表的值相似。这些研究表明，H-H COMBO是用于大型溞培养和生物测定测试的可接受培养基。使用镰形纤维藻的冷冻等分试样进行了额外实验。尽管平均繁殖力（64±7）和成年体长与喂食新鲜藻类的大型溞的值相比显著降低，但3,4-DCA的NOEC>25微克/升。在生物测定测试中使用这种替代食物源似乎很有前景，但喂食率的进一步优化是必要的。
