| Spawning sites are usually located in the middle or upper reaches of large rivers. They are especially abundant just downstream of from barriers, such as weirs. The nest is an oval or circular depression up to 40 cm in diameter (Ref. 6114). During spawning, the lamprey gather in small groups. The females attach themselves to a stone by means of their suction cup, dig a nest in the gravel and deposit the eggs there. The males attach themselves the same way as the females and fertilize the eggs. The eggs are not protected (Ref. 30578). |