M/F ID and Behavior question

[TexasNano]

New to keeping Apistos. LFS said these were Apistogramma Cacatuoides, one male, one female. The yellow one (advised was female) chases the other around constantly (also harasses pygmy corys and otocinclus), especially at feeding time. I was hoping this was temporary, but it's been going on now for a couple of weeks. The "male" keeps to himself as much as possible and today I noticed his black stripe has started to fade. Is this expected from a pair? Did LFS ID them correctly? Thanks for your help. Much appreciated.

 

[anewbie]

They are male/female; the male looks kind of off - small and I can't tell from the photo if it is young or something wrong with it. The female is in breeding mode and wants a male to breed with. Cockatoos don't pair. Not in the sense you are thinking of so they will never be long term tranquility with them.