EFFECT OF CADMIUM AND CHROMIUM ON TWO POPULATIONS OF THE POLYCHAETOUS ANNELID CAPITELLA CAPITATA
镉和铬对多毛类环节动物小头虫两个种群的效应

The purpose of this investigation was two-fold: (1) to compare the effects of two toxicants, cadmium and chromium, on two populations of Capitella capitata, and (2) to initiate a marine bioassay program at the Institute of Oceanology at Qingdao. These two metals were selected for study since they occur in elevated concentrations in industrial wastes discharged in the Qingdao area. The effect of these two metals on polychaetes has been reviewed by Reish (1980) and Eisler (1981) and summarized.The data for survival of the two populations of C. capitata to chromium and cadmium are summarized in Tables 1 and 2, respectively. The calculated 96h LC50 to chromium was 0.063 and 1.7mg/l for the Qingdao and Long Beach populations, respectively. Analysis of these data indicates that the difference in results with these two experiments is statistically significant. The calculated 96h LC50 to cadmium was 1.0 and 0.6mg/l for the Qingdao and Long Beach populations, respectively. The difference between these two LC50's is not statistically significant.The 96h results indicate that the Qingdao population of C. capitata was significantly more sensitive to chromium than the laboratory bred Long Beach population; however, the Long Beach population was slightly more sensitive to cadmium than the Qingdao specimens. It is possible that the field collected specimens of C. capitata had not been acclimatized to laboratory conditions for a sufficient length of time prior to experimentation and, furthermore, the laboratory bred Long Beach population was obviously more adapted to the laboratory environment.Comparison of the 96h LC50 data with the published results of others (Table 3) show that these figures for cadmium were lower than previously reported for adults of the C. capitata. However, if the previous results with C. capitata are used for comparative purposes, then several species are more sensitive to cadmium than C. eapitata.