Acute toxicity of nonylphenol ethoxylate-6 to whiteleg shrimp, Penaeus vannamei (Boone, 1931) (Decapoda, Penaeidae)

Nonylphenol ethoxylate-6 (NP6EO) is widely used in industrial and domestic products and easily detected in the environment. The toxicity and estrogenic potency of alkylphenols have been investigated in several studies. However, to the best of our knowledge available, acute toxicity data about the effects of NP6EO on decapod and aquatic ecosystem in literature is yet scarce. Therefore, in this study the adult male and female whiteleg shrimp, Penaeus vannamei, were exposed to various concentrations of NP6EO (0.04, 1, 5, 25, 125, 625 µL L-1) for four days. Acute toxicity potential of NP6EO on adult P. vannamei was assessed by calculating LC50 for different times. Median lethal concentration (LC50) of NP6EO at 96 hours was 7.017 μL L-1. The LC50 of this compound revealed a positive correlation between shrimp mortality and exposure periods. The data exhibited that NP6EO was considered as "toxic" to P. vannamei and further toxicity assessment to other species is strongly recommended.