I gave one of my red comet platy fry to my cousin who has 60 of them in a very big tank with a pair of convicts, the convicts treat the platies like there own babies!!

Im not even sure if the convicts would guard there own young like this!! I thought thy where going to eat them!! My platy can be distinguised from the others cause the have a black spot in the dorsal fin and on the head

WHat could have caused the convicts to do this?