Dario dario are a really mixed bag, just like bettas. Some will take only take live food when some will happily eat dry food, the latter being VERY rare. I find most will eat frozen baby brine shrimp and LOVE frozen mysis shrimp... as long as you don't feed them live foods that is. Bloodworms tend to make Dario dario fatter than they should be. Also, since most dario dario are males, make sure you are buying a female, females can be an all around kind of blueish gray, to looking like a stressed out male.