Ethnobotanically important plants with piscicidal properties used for traditional fishing in Chirang district of Assam, Northeast India

The use of certain plant species in traditional fishing for their piscicidal or stupefying effect is widespread among many fishing communities in northeast India. Plant poisoning is one such traditional method for fishing practised in the Chirang district of Assam in northeast India. This paper identifies six different species of plants (Polygonum hydropiper, Spilanthes paniculate, Parthenium hysterophorus, Alistonia scholaris, Albizia procera, Ageratum conyzoides) belonging to four different families (Asteraceae, Apocynaceae, Fabaceae and Polygonaceae) which are used as natural poison for capturing fishes in the study area. Maximum number of species (50%) was recorded in family Asteraceae while the remaining families recorded one species each. The most common mode of application was in the form of a grounded paste or an aqueous extract while in some cases the raw plant itself were used. All of these plant toxins were reported to probably affect the swimming and respiration of the fish on application. However, detail mechanism of their toxic action needs to be evaluated fully. This study has identified some potent natural piscicidal plants which may be further investigated for widespread application in aquaculture and allied industry.