Complex sentence: The mechanical action of the waves is the environmental trigger for hatching, and the rapidity of hatch, in less than one minute, indicates that it is probably not an enzymatic function of softening the chorion, as in some other fishes.
Split into simpler sentences: The mechanical action of the waves is the environmental trigger for hatching. The rapidity of hatching, which occurs in less than one minute, indicates that it is probably not an enzymatic function of a softening of the chorion as in some other fishes.