This study on the perception of fish behavior in relation to the hydrological period has been carried out in kukama-kukamiria communities located in Bajo Huallaga, Bajo Marañón and Bajo Ucayali, in the Loreto Region. The main objective is to describe local knowledge about the behavior of aquatic fauna during hydrological variations in the Peruvian Amazon. This is a qualitative, ethnographic research that used the semi-structured interview technique, using an interview guide as a data collection instrument. 15 expert kukama fishermen were interviewed. The life cycle of fish is interpreted in relation to fluctuations in the river cycle. It is concluded that the Kukama have excellent traditional knowledge about the behavior of fish, not only due to the constant practice of fishing, but also because this knowledge is part of the traditional knowledge transmitted from generation to generati...