The biochemical composition of the nauplius stages of Tetraclita squamosa rufotincta Pilsbry

The biochemical composition of laboratory-reared nauplius stages of Tetraclita squamosa rufotincta Pilsbry during development is described. The larvae lose weight progressively during development. Proteins contribute most of the energy during development and it is suggested that protein serves as the source of nitrogen and glucose for the formation of chitin. Lipids contribute some energy during the initial stages of development, and later may serve as an energy source for the cyprids. The rise in RNA values is related to the increase in protein metabolism, particularly in the later stages. DNA values increase only during the early stages suggesting that later development is concerned mainly with organization of the cells and the formation of the cyprids. The results are compared with those on the developing embryos of the same species.