<p> Rice paddies and their surrounding habitats, including rivers, canals, and other landscape elements, support diverse organisms. However, the recent consolidation and automation of rice paddies to improve farming efficiency has resulted in a loss of connectivity between paddies and surrounding water bodies, leading to the deterioration of paddy ecosystems. In this study, we conducted species distribution modeling using MaxEnt to explore the suitable habitat areas for <i>Pseudorasbora parva</i>, a primary occupant of rice paddy ecosystems, and evaluate the contribution of the surrounding habitat to its occurrence. Most of the <i>P. parva</i> collection sites were located in water bodies flowing through plains. In a MaxEnt model for <i>P. parva</i>, river-connected canals contributed most positively to species occurrence, and the anticipated reduction or loss of connectivity between these canals led to predictions of a decrease in the suitable habitat for the species. On the other hand, the existence of rice paddies themselves had no significant effect on <i>P. parva</i> occurrence. The species distribution modeling and fluctuation prediction highlighted the importance of canal networks that connect rivers and rice paddies for supporting <i>P. parva</i> habitats. This trend can be extended to other aquatic animals that inhabit rice paddy field ecosystems in different regions. To retain rice paddy ecosystems, it is necessary to verify the benefits of biodiversity considerations for the sustainability of agricultural management.</p>