Acute toxic effects of crude oil pollution on Nauplius Ⅱ of Chthamalus challengeri

Oil pollution is a severe threat to the marine ecological environment. To figure out the acute toxic effect of oil pollution on marine organisms, the effects of water-accommodated fraction(WAF)of crude oil on nauplius Ⅱ of Chthamalus challengeri were examined under the condition of the laboratory adopting the static test method. The results showed that: (1) The survival rate, developmental rate and Catalase (CAT) activity were not significantly affected after being stressed by WAF for 48 h (p0.05). (2) With the increasing of the concentration of WAF, phototaxis and Superoxide dismutase (SOD) activity did not show significant variation (p0.05). As a whole, the fluctuation of phototaxis of nauplius Ⅱ exhibited a downward trend after rising first and an upward trend was observed for the fluctuation of the SOD activity. Phototaxis and SOD activity were significantly changed only by WAF of 27 mg/L(p0.05).(3) The reason for the low toxic effects on the larvae might lie in the stronger resistance of larvae to oil pollution or the small amount of volatile and low boiling point hydrocarbon dissolved in WAF. (4) The phototaxis and SOD activity of nauplius Ⅱ might be employed as monitor indicators for the pollution of oil in the ocean, because they were much more sensitive and precise to reflect the acute toxicity effects of WAF than that of survival rate, developmental rate and CAT activity.