2922 Environment & Ecology 35 (4A) : 2922—2925, October —December 2017 Website : environmentandecology.com ISSN 0970-0420 Comparative Growth Study of Indian Major Carps and Exotic Carbs in Pond Polyculture System Kapil Deb Nath, Nabadeep Saikia Received 30 December 2016; Accepted 1 February 2017; Published online 20 February 2017 Abstract An experiment was carried out to com- pare the growth performance of Indian Major Carps (IMC) and exotic carbs in polyculture system in two earthen ponds during July, 2015 to February, 2016. Areas of both the experimental ponds were of 0.1 hectare with an average depth of 1.5 meter. In pond one Indian Major Carp (IMC) catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus mrigala) and in pond two exotic carp, silver carb ( Hypophthalmichthys molitrix ), grass carp ( Ctenopharringodon idella) and Common carp (Cyprinus carpio) were stocked at the rate of 6,500 fingerlings/ha. The stocked fishes in both theponds were fed at the rate 3% of body weight with rice bran (RB ) and mustard oil cake (MOC) at 1: 1. It was observed that, the gain fish body weight and to- tal length of the fish stocked in pond two were maxi- mum compared to that of fish stocked in pond one. Keywords Growth, Indian major carp, Exotic carp, Rice bran, Mustard oil cake. Kapil Deb Nath, Nabadeep Saikia Krishi Vigyan Kendra, Assam Agricultural University, Arunachal, Cachar- 788025, Assam, India e-mail : kapildebnath88@gmail.com *Correspondence Introduction Polyculture is the system in which fast growing com- patible species of different feeding habits are stocked in different proportiomns in the same pond has been practicing from the very beginning of the fish culture in China and in Indian sub-continent. The basic principles of the polyculture , i e culture of species of different feeding habits in the same pond is the best utilization of natural foods of different strata and zones without any harm to each other. It is a fact that, polyculture may produce an expected result if the fish with different feeding habits are stocked in proper ratios and combinations. In polyculture system one species improve the food accessibility for other species and as a result am- plify the entire fish [1—2]. Fish is the major pro- tein source contributing about 58% of total animal protein intake. Fish is the most excellent source of protein for human. fish can be a valuable and cheap source to supplement the protein provisions to mal- nourished population of the world. Fish is regarded one of the most valuable resources to supplement the protein provisions in human diet [3]. Since, fish protein is considered as the cheap source of animal protein, fish production has captured a greater at- tention due to the wrldwide scarcity of animal pro- tein. The growth performance of indian majo carps (Lbeo rohita, Ctla catla and Cirrhinus mrigala) can be improved by providng accessible enough amount of natural food and balanced artificial diet. Keeping the production performance of polyculture system an on farm trial (OFT) was conducted on composite