GEOGRAPHIC-DISTRIBUTION, SEASONAL LIFE-CYCLE, BIOMASS AND PRODUCTION OF A PLANKTONIC COPEPOD CALANUS-SINICUS IN THE INLAND SEA OF JAPAN ANDITS NEIGHBORING PACIFIC-OCEAN

The geographical distribution, seasonal life cycle, biomass and produc tion of a copepod Calanus sinicus were investigated in and around Kii Channel of the Inland Sea of Japan. The distribution center of the pop ulation was located in Kii Channel. The pattern of the seasonal variat ion in abundance of copepodites and adults differed geographically wit hin the study area. In Kii Channel, for example, they were most abunda nt in June-July and least abundant in October. Over the study area, th e reproduction of C.sinicus took place throughout the year, indicating the absence of diapause phase. In adults, females usually outnumbered males. The prosome length of late copepodites and adults was inversel y correlated with water temperature. The annual mean biomass was highe st (4.87 mg Cm-3 or 231 mg Cm-2) in Kii Channel. The potential product ion rate of the population exhibited a seasonal variation more or less similar to that of the biomass and the annual potential production ra te was 358 mg C m(-3) year(-1) (14.1 g C m(-2) year(-1)) in Kii Channe l. Daily production and biomass (P/B) ratios in Kii Channel increased from O.11 at 11.8 degrees C to 0.26 at 20 degrees C.