i guess it could be a rear pattern i know most juvies have strips and develop spotts when they start maturing you said 9 inch mine had spotts at 8 and he is now 10 they grow fast about an inch or more per month if feed regularly
oh feeders ummm goldfish or silver sides even rosy minows or guppies anything small enugh to fit in his mouth you would be surprised how big they will strech they jaw mine can eat med size golfish about 2 or 3 inch