- When it was 13 days old,the bait would changed to nauplius of Artemia and baby-size Cladocera、Copepoda.
- It was found that the dominant organisms in the surface water resources in Xi an were Tubifex, Cladocera and Chironom.
- Stomach contents examination of two specimens showed a large volume of Spirogyra sp., Cladocera, sediments (sand) and unidentified organic matter.
- The average biomass of zoo-plankton is 1. 10 mg/1, in which the copepoda presented 30. 9%, the cladocera - 24. 5%. The rotifera and protozoa are 26.4%. and 18.2%, respectively.
- Through this survey we could got such conclusion.Among zooplankton, the species of Copepods was the most, but its abundance was fewer than that of Chaetognatha and Cladocera.
- Therefore, fish's predatory control on zooplankton is higher in shallow lakes, resulting in less possibility of grazer control of algae by the Cladocera.