Needle fish are very skittish. Try some floating plants for it to hide in. You will probably have problems down the road as the oscars outgrow it and the tank. How big is the needle fish?
My oscar are eating everything i throw in the tank. hard to keep a feeder swiming to see if my needle will take it, but dont seem like hes going after them anyway, dont really wanna over feed my oscars. i might try throwing in cricket tommorow. see if it help.