The drifting fish eggs are more likely to collide with ships, rocks etc.
as they hatch while migrating through the river. For fish resources
protection and waterway management, it’s important to clarify the upper
threshold of hitting velocity and the effect of the hitting shock on
their hatching. Thus, natural spawned and domesticated fish eggs were
studied and compared. The effects of hitting objects, hitting velocity
and the developmental level of the fish eggs on their hatching was also
studied. The developmental stage was the most sensitive factor to
hitting shock. Almost 70% of natural spawned semi-buoyant fish eggs
can’t hatch successfully when the hitting velocity was 4.4 m s
-1 and collided with rock, and this hatching rate was
about 10%-30% higher than that of farmed ones at the same conditions.
The results are of great significance for the protection of fish
resources in the high-velocity rivers.