둥근성게의 수정과 발생에 미치는 PCO2의 영향

Abstract

We examined the effects of pCO2 on the fertilization success rate and development of the sea urchin Stronglyocentrotus nudus, one of abundant and common organisms found in Korean coastal waters. We exposed sperms of S. nudus to seawater of different pCO2 levels ranging from 380 ppmv to 6000 ppmv, and found that the fertilization rate of the sea urchin was lowered drastically even at pCO2 level of about 500 ppmv, which we could reach as early as 2050s. When the egg of S. nudus was exposed to seawater of high pCO2, the fertilization success rate did not change, and we could conclude that the sperm is responsible for this unprecedented low fertilization success rate. This low rate, however, was not due to the motility of the sperms since the motility was rather insensitive to pCO2 within the range of our investigation. We further examined the effect of CO2 on the development using eggs fertilized under 380 ppmv. The eggs were divided into three groups. The first group was exposed to CO2 treated water until plutes stage, and the second one was exposed during hatching stage (from fertilization to hatching) and then returned to the water with the water treated at 380 ppmv. The third group was exposed to CO2 treated sea water after hatching. Under 550 ppmv the development rate was not affected by pCO2. At 750 ppmv the development rate was decreased, but the one exposed during the hatching sta