More specific, the movement of members of a population as eggs and larvae from the spawning ground to the nursery area, as juveniles to the feeding grounds, and as adults to the spawning area.

• 更特别的，族群的集体运动如鱼卵或幼鱼从出生地到到育幼区域，稚鱼时到觅食场，与当成鱼时到产卵区域。无法完成这个周期的个体(流浪汉)对基因库没有贡献。