Rainbow Trout ‒ Life cycle

The life cycle of trout, like that of other fish, includes several fascinating stages. It begins in the upper parts of rivers, where males and females gather for breeding and eggs are fertilized. Mating can occur communally, with a single male often mating with multiple females in favorable areas. In temperate regions, the breeding season spans autumn and winter, during which males prepare their mating grounds by swiftly flicking their fins. After laying and quick fertilization, the parents provide no further care for the eggs. Interestingly, embryonic development continues even after hatching. Newly hatched trout, known as alevins, feed from a large yolk sac attached to their bellies. As the yolk sac is gradually digested and diminishes, the young trout begin to feed on food from their environment and are then referred to as fry. In both European and North American trout species, adults develop into distinct forms adapted to different environments. Some live in fast-flowing freshwater streams, others inhabit lakes, and still others are migratory, living in oceans but returning to rivers solely to reproduce.