This document summarizes the life cycle of brown trout and sea trout, which are actually the same fish. It describes the stages the fish goes through from egg (ovas) to alevin, then fry and parr. When the fish reaches a certain stage, it must make a choice to become either a brown trout living in freshwater like lakes or rivers, or a sea trout that undergoes a process to live in saltwater oceans, providing more food but also more predators. The document concludes by mentioning some alevins are being kept and observed by a class.