Like most creationists you view this as an all or nothing deal and not the gradual stepwise process which it required. The problem with behavior is that only in very few cases doe it leave any traces. Sexual and reproductive behavior is particularly absent of evidence. That being said we can see many examples of similar but less dramatic behavior in other fish living in similar environments. The whole gamut of behaviors described [depositing eggs, male-female roles, use of plant for cover, use of plants to deposit eggs, jumping out of water] can be seen in many other fish in one degree or another.
For the credulous, a lack of explanation and ignorance in general means 'god did it', for others it means research should be done. You belong in the first group.