Abstract
Energy budget calculations, based on published values for changes in biochemical composition and oxygen consumption, have confirmed that metamorphosing bonefish (Albula sp.) larvae from the Gulf of California receive all of their metabolic energy requirements from the breakdown of endogenous reserves. The calculations showed that during metamorphosis, about 80% of the energy was supplied by lipid, and most of the remainder was provided by keratan sulfate glycosaminoglycan. These results support the suggestion that keratan sulfate can function as a storage polysaccharide, a novel function for glycosaminoglycans in vertebrates.