THE SELECTED AQUATIC FAUNA OF A RICE FIELD ECOSYSTEM WITH NOTES ON THEIR ABUNDANCES SEASONAL DISTRIBUTIONS AND TROPHIC RELATIONSHIPS T Miura, R M Takahashi, and WH Wilder University of California Mosquito Control Research Laboratory 5544 AirTerminal Drive Fresno California 93727 ABSTRACT The aquatic fauna of rice fields is remarkably rich 62 species or species groups of organisms were regularly collected, and sporadically another 23 different kinds of organisms were collected. The most abundant organisms in the rice fields were crustaceans, while insects dominated in the species composition. The mosquito fish Gambusia affinis (Baird & Girard) is a top predator, but predacious insects, damselflies, notonectid bugs and beetle larvae probably play an important role in suppressing mosquito and chironomid larval populations in the Fresno West side rice fields because they are so abundant in the ecosystem.