i have 2 3inch jar but the other one has a hump on its back and the other one is normal. The hump on its back is like a spoon shaped. what is the difference between the two?
could be a spoon head body shape, very popular with Asian arowana... or though its too young to tell it might just be fat growing ready for a growth spurt.
you don't have pictures hahaha? The first looks like it be a jar and the second looks like it could be a lei. Jars have a sloped forehead and are taller, where lei's are a bit more slender bodied and their foreheads go straight to their backs....