Replacement of Rotenone by Locally Grown Herbal Extracts

The studies were conducted to assess the piscicidal activity of 10 locally available plants on freshwater trash fishes. The studies were focused on the laboratory determination of lethal concentrations (LC50) through a "static bioassay test". Leaf extracts of Nerium oleander (Family Apocynaceae), Cannabium sativum (Bhang, Family Cannabaceae), Datura alba (Family Solanaceae), Adenophyllum spp. (Berri patta, Family Asteraceae), Nicotiana tabacum (Tobacco, Family Solanaceae) and Ricinus communis (Arind, Family Euphobiaceae), while root extracts of Parthenium spp. (Family Compositeae), Calotropis procera (Family Asclepiadaceae), Achyranthes aspera (puth kanda, Family Amaranthaceae) and seed extracts of Ricinus communis and Strychnos were utilized for these studies. Based on the 96 h lethal concentration, Ricinus communis, Datura alba and Strychnos nux vomica (Kutchla, Family Loganiaceae) showed the strongest piscicidal activity to fish. During exposure, fish exhibited discoloration, gulping for air, erratic swimming, loss of reflexes, slow opercular movement and ultimately settling at the bottom motionless. The trial toxicity tests showed that locally available plants have the potential to be used as piscicides, which can be an alternate to an expensive and scarcely available imported rotenone for eradication of undesirable fish species present in fish ponds. © 2010 Friends Science Publishers