well, depends who you ordered it from and the quality of the fish.
Wild caught fish are more colorful, sheen, and more vigorous, they are excellent jumpers as well.
i think the easy way would be if it does not recognise pellets as food. im not very sure but it makes sense rite?
when they are starving, they will eat anything. Perhaps, pellets are more tasty than the food in the wild, but they don't eat like pigs as aquarium raised fish do unless its been kept in aquarium so long.
well i got him last week,hes around 5 inches,when i put him in the tank he hid straight away for a good while and when i take a close look at him he goes mad,banging off the glass,when i put pellets in hes not that intrested,but when i put crickets in he knows what they are,lucky i have a heavy lid b/c he jumps so high catching the crickets,i must put up a pic,thanks