The present study was designed to test the effects of type of binder on growth, nutritional physiology, total apparent digestibility, and some elements of the energetic balance of early O. maya juveniles. Two experiments were performed. One was aimed at evaluating the effect of type of binder on growth, nutritional physiology, and energetic balance and the other at knowing the effect of the binder on total apparent digestibility of O. maya. Binder type affected growth and survival of early O. maya juveniles. Octopuses fed alginate-bound crab meat lost weight and died, revealing that this type of binder limits nutrient absorption from the diet. In contrast, when gelatin was used as binder, energetic balance was similar to that obtained in animals fed natural crab, indicating that octopuses can digest gelatin. Apparently, gelatin promotes absorption of nutrients similar to that observed when octopuses were fed pieces of fresh crab. Salivary glands produce enzymes that are used to predigest the food. Results of the present study indicate that octopuses require higher enzyme activity to digest fresh crab than when animals are fed gelatin-bound crab paste, and that intracellular digestion in the digestive gland is similar in animals fed either type of diet. The present study reports, for the first time, differences among binders used for cephalopods' diet. Although no compounded feed formulations are available for cephalopods, it is a necessary step in the search for an adequate compounded feed for this novel species in aquaculture. (c) 2008 Elsevier B.V. All rights reserved.