Effect of salinity, temperature and dissolved oxygen on survival of Perinereis nuntia (Polychaeta, Annelida), in vitro

This study was performed for a period of 3 weeks, on the survival of Polychaeta Perinereis nuntia, at various salinities, temperatures and dissolved oxygen levels, in laboratory condition. Among these factors, salinity had the most significant effecton the survival of P. nuntia. There were one control group and 3 treatments at different salinities, includeing 1/5 (7.1 ppt), 3/5 (21.3 ppt) and 7/5 (49.7 ppt) of sea water salinity. The salinity of the control group was 35.5 ppt. Maximum rate of survival was observed in control group with 70% mortality and the minimum was in 7.1 ppt treatment by full fatality in the first week. There was significant difference in survival rate of various temperature treatments (p<0.05). Minimum and maximum survival rate in temperature treatments were in 44º Ϲ with 33% and 24 º Ϲ with 70%, respectively. Dissolved oxygen concentration was the least effective factor on survival of P. nuntia. The highest survival rate was in 5-6 ppm of dissolved oxygen concentration with 80% survival and the lowest was in 7-8 ppm with 73% survival. Results showed that the maximum survival rate of Perinereis nuntia was in dissolved oxygen treatments and the highest mortality rates were in different concentrations of salinity.