강화도 주변해역 부유성 새우류 Acetes chinensis와 Leptochela gracilis의 월별 개체군 변화

Abstract

Monthly changes of planktonic shrimp populations were investigated near off Kanghwa Island. Planktonic shrimps were monthly collected by a stow-net at three stations from March to December in 2012. Water temperatures and salinities were simultaneously measured, using an YSI. Water temperatures ranged from 3.8-27.4°C, which was the highest in August and the lowest in March. Salinities ranged from 14.7-28.6 PSU, which was highest in June and the lowest in Mid-September. Salinities fluctuated during the summer months and stations, being resulted from river freshwater inputs. Number of individuals and biomass of planktonic shrimps were relatively higher in September and October while they were relatively lower in July than other months. Among shrimp species, Leptochela gracilis was dominant in March to July, while Acetes chinensis was dominant from September to November. Mean carapace length of A. chinensis increased from March to July. Small sizes of A. chinensis occurred from September. Mean carapace length of L. gracilis increased from March to June and Small sizes of L. gracilis occurred from July. A. chinensis and L. gracilis had one generation in a year. This research found that the population changes of planktonic shrimps varied with stations and seasons in the research area.