The yoyo's are 1 year old. If you buy them, buy more then 3!!! I bought 3 from a wholesale lfs. When I bought them, they were all the same size. HOWEVER, as the months rolled on, the 2 that you see have grown to a few inches. The other NEVER grown but stayed the same size. Not only that, he never really played around, and always seemed to be "resting". I have no clue what happened? anyone have an idea? Cant be stunted because, at the time, the tank wasnt even crowded.
ANYWAY, I really do like the fish from the family distichidus. The Affinis are a nice addition, however be warned that they do nip fins on occasion. Kind of funny though. One time an affini went after my red tail shark to nip (I was watching), this happened before and I guess the red tail suspected it cause he chased that fish for like 10 seconds.
Affinis will nip but are not aggressive at all to any fish. As I heard from other people though, various other fish from the disctidus family can hold there own against aggressive cichlids (dist. sex. as one)