water flea 水蚤
crustacean 甲壳类
plankton 浮游生物
freshwater 淡水
aquatic 水生的
invertebrate 无脊椎动物
branchiopod 枝鳃类
1. The scientist collected samples of tetragon from the lake for analysis.
科学家从湖中采集了枝角类样本进行分析。
2. Microscopic examination revealed a dense population of tetragon in the water sample.
显微镜检查显示水样中枝角类密度很高。
3. The presence of specific tetragon species indicates good water quality.
特定枝角类物种的存在表明水质良好。
A: Did you find any interesting organisms in the pond?
A：你在池塘里发现什么有趣的生物吗？
B: Yes, I saw a few tetragon swimming near the surface.
B：是的，我看到几只枝角类在水面附近游动。
1) 枝角类动物（water flea）的统称。
2) 某些淡水贝类的俗称。
3) 水生无脊椎动物的一种。
4) 作为水质监测指示生物。
1. [生物学] 枝角类；水蚤（一种小型淡水甲壳类动物）。
e.g.
The tetragon was invisible to the naked eye.
那只枝角类肉眼不可见。
noun
1. A small crustacean, typically of the order Cladocera, resembling a flea; a water flea.
2. Any of several bivalve mollusks, especially of the genus Tetragonula (note: distinct from the crustacean usage).
Synonym: water flea, cladoceran