Ecotoxicity and hematological effects of a natural insecticide based on tobacco (Nicotiana tabacum) extract on Nile tilapia (Oreochromis niloticus) - doi: 10.4025/actascibiolsci.v35i2.14131. Acta Sci. Biol. Sci. 2012;35(2):157-162. doi:10.4025/actascibiolsci.v35i2.14131