Worldwide, there is an increasing need for sustainable crop production making efficient use of scarce natural resources. The integration of fish culture in rice-based farming systems has a long tradition in parts of Asia and, after a period of heavy pesticide use, rice-fish culture is currently regaining importance in the region. The economic viability of this integrated enterprise has been documented in many studies, however, agro-ecological impacts have received little attention. This book deals with the contribution of two common and widespread fish species to Integrated Pest Management (IPM), particularly the biological control of pests, in rice. In two introductory chapters, current ecological knowledge on the husbandry of common carp and Nile tilapia in rice fields is reviewed, and an overview on insect and snail pests associated with rice production in Asia is provided. In the following chapters, a detailed description of design and implementation of the experimental work from five consecutive seasons is given: functional response studies in aquaria, the activity pattern of fish in rice fields, the qualitative and quantitative composition of the arthopod fauna in rice-fish and rice monoculture, and the impact of fish on snails at various levels of fish density and snail infestation. A preliminary stochastic, individual-based model is developed which investigates the population dynamics of the golden apple snail under different predation scenarios. Biological control of pests by fish, and the prospects for integrating fish into rice fields are discussed in the light of the results. Conclusions are drawn on how pest control by fish can be enhanced. The text concludes with recommendations on future research.