NutriDiet Fly Larvae 34 grams, Seachem. NutriDiet Fly Larvae is the ideal solution for feeding a natural diet to fresh and saltwater fish. It is perfect for the aquarist seeking variety or an alternative to pelleted foods. Studies have shown that Fly Larvae can be used to condition a variety of fish for breeding. The unique packaging process of NutriDiet Fly Larvae locks in moisture and nutrients making it more palatable and more nutritious than freeze-dried Fly Larvae.