摘要:We studied the vertical distribution of zooplankton in shallow Lake Suwa monthly during two summers. Polyarthra spp. and Eodiaptomus japonicus showed marked diel changes in their vertical distribution patterns. E. japonicus displayed a typical migration, avoiding the surface and maintaining a high abundance in deeper water during the day. Polyarthra spp. showed the reverse migration pattern, with high abundance near the surface during the day and uniform distribution during the night. This distribution pattern seems to be related to the distribution of an invertebrate predator, Thermocyclops sp., which migrated downward during the day.