To assess the basic biology of invasive exotic fish in Laguna de Bay including their potential impact on their novel ecosystem. The specific objectives are as follows: 1. Assess spatio-temporal distribution and habitat preference of invasive exotic fish in Laguna de Bay. 2. Evaluate prey item abundance and composition of invasive exotic fish in Laguna de Bay. 3. Determine reproductive parameters of invasive exotic fish in Laguna de Bay. 4. Conduct a mapping of invasive exotic fish in Laguna de Bay. 5. Assess the basic biology of invasive exotic fish in Laguna de Bay including their potential impact on their novel ecosystem.