The effects of salinity and temperature on the toxicity of copper to 1-day and 7-day-old larvae of Hediste (Nereis) diversicolor (O. F. Muller).

The effects of salinity and temperature on the toxicity of copper to 1-day and 7-day-old larvae of Hediste diversicolor were tested using factorial analysis. Mortality of larvae was influenced by salinity, temperature, and copper, but 1-day-old larvae were more susceptible than the 7-day-old larvae. Resistance to copper increased with age. Low concentrations of 5 and 20 micrograms/liter copper were more inhibitory to 1-day and 7-day old larvae, respectively, than were higher copper levels. The responses of 1-day-old larvae to copper levels from 0 to 20 micrograms/liter and 7-day-old to copper levels from 0 to 100 micrograms/liter copper were complex. Increasing salinity 7.6 to 30.5% reduced both copper toxicity and protozoa/bacteria attacks.