Just confirmed this:
Gyarados Male 6-7/14/2-4/15/17/26
Gyarados Female 19-20/11/31/7/22/18
Magikarp (can't remember genre) 19-20/11/31/31/22/18
This meant Magikarp got all his IV's from his mother and a 31 random Spa IV.
So I tried with my 31/31/31/31/31/31 Female Larvesta and a random Ditto and...