Successful rearing of larval stages of aquatic organisms is a challenge for aquarium hobbyists, an aim and tool for aquatic ecologists and ecotoxicologists, and a necessity for the success of the aquaculturist. All these people will agree that the primary problem in any type of larval rearing is that of food. Ideally, one would prefer to feed larvae their natural diet, which is characterized by a wide diversity of nutritious live organisms. Although not a 'natural' food, Artemia have been successfully used by many as food for larval organisms. It is perhaps surprising that such success could be attained with a food from such an unusual (i.e. hypersaline) environment. Some recent experiences suggest that the use of Artemia does not absolutely guarantee success.