King British Tubifex Treats are suitable for all aquarium fish, plus turtles and terrapins. They are a natural river-dwelling worm, harvested, then freeze-dried immediately to retain flavour and nutritional value. The dried worms into one-centimetre cubes, making them easier to feed to your fish. Tubifex is the type of food that a fish would choose to eat in the wild and provides a welcome treat and protein-rich nutritional supplement to any fish.