he needs alot of attention! he is very small and very skinny. he needs beeter food more often.
try frozen blood worm (which isnt great but its good to build up there appetite), very small or chopped up earthworm, black worms, chopped market prawn, mussel and even try hikari sinking carnivor pellets.
make sure every thing is chooped up nice and small, his mouth will be tiny! he is more then likely trying to chew on food thats to large for him and not being able to actaully eat alot.