Observation on the Swarming Behavior of Perinereis aibuhitensis

The swarming behavior of Perinereis aibuhitensis Grube was observed and investigated at Cixi Longshan beach in Zhejiang Province and in the Huchengang fisheries breeding factory in Ninghai during 2000.1-2000.12. The results were as follows:Swarming occurred from the middle of April to the middle of October when the surface temperature of marine water was 19 0-26 2℃. There was a swarming peak 2-4 days before the spring tide. Swarming behavior was also affected by the state of the tide and sunlight. One swarming cycle lasted for about half a month.