Activity pattern of fish in rice fields uri icon

abstract

  • The culture of fish in rice fields is a traditional integrated farming practice which faced a decline during the Green Revolution in Asia but today has new scope with the increased adoption of integrated pest management practices. A widely used system is digging a pond within or adjacent to the rice field so that fish have free access to pond and field. Systematic knowledge on the activity pattern of fish in rice fields is lacking to date, but is crucial for understanding their role in this ecosystem as well as their potential as biocontrol agents of rice pests. We therefore conducted a study to determine the spatial and temporal distribution of Oreochromis niloticus (mixed sex), O. niloticus (all male) and Cyprinus carpio at three times of day (07:00 h, 12:00 h and 17:00 h) during early, middle and late rice crop development in the dry and wet season. Nets were installed in the rice fields that served as barriers against fish movement during sampling, In addition, ponds were netted to allow sampling of all fish. Results show that regardless of fish group or sampling time, more than 50% of the fish can be found in the rice field, In the wet season, fish distribution within the rice field was uniform with 16-18% of the fish sampled in each of the four field compartments, whereas in the dry season significantly (P < 0.01) more fish were caught in the first compartment adjacent to the pond, The results are discussed in view of the changing conditions in the rice field due to crop development, The presence of large numbers of fish in the rice field provides evidence for the hypothesis that fish are potentially important predators of rice pests.

publication date

  • 1996
  • 1996
  • 1996