Diamond Breeding Phenomenon

[Sephiroth]

I'm trying to breed a relicanth, and I have a male gyarados and a female relicanth. It should always pop out as a relicanth, right? Well, I gave the Gyarados a Power belt, or band or whatever, the one that is HP related, and I gave the relicanth the power item that relates to Defense. Gyarados has 31 IV's in HP, Relicanth has 31 IV's in defense so it just seemed like maybe it could work out like it did in gold and silver, so that they pass them on. Instead what I saw was that the the male gyarados and the female relicanth were giving birth to magikarp instead of relicanth!!! Can somebody explain why this was happening? I read about exceptions to the baby species = mother species rule, and this wasn't one of them.

[Sephiroth]

Update:

Removed the items, and still was getting magikarp.
Replaced the male gyrados, which is in the water 2 egg group and was lower level than the relicanth, with a seadra, which is in the water 1 egg group and was a higher level. Then I started getting Horsea.

It seems that there may be more exceptions to the "baby species = mommy species" rule than are talked about in the breeding guides?

[LeoReborn]

The Egg types only say which pokemon have eggs together, I know it wouldnt be easy, but try switching genders, Or.... if you have a Ditto, use it with Relicanth.

[Declan_23]

Yeah, but with Ditto, he won't get the desired IVs

[LeoReborn]

Yeah, but with Ditto, he won't get the desired IVs

True. If you could somehow switch their genders, that would work.

[d00mn1nja]

Try finding a ditto with good IV's. Or just tough it out. Take a chance with a random ditto, and love your little baby Relicanth for what it is! I know you probably disagree which is cool. I understand wanting certain IVs.