Abstract
The ultrastructure of the xanthophores of larval goldfish at various develop-mental stages was examined, with special reference to the appearance and accumulation of lipid particles in the xanthophores. In xanthophores of the hatching larva, numerous pterinosomes were present but no lipid particles were observed.The lipid particles, homogeneously electron-dense and 60-80 mμ in diameter, appeared in the neighborhood of the nuclei of the xanthophores in larvae 5 days after hatching.They formed con-glomerates of varying sizes.The conglomerates of lipid particles increased in size along with the development of the larvae, and a considerable number of lipid particles gradually become distributed freely into the dendritic portion of the xanthophores.The mechanism of accumulation of these lipid particles in the xanthophores is discussed in relation to those of other cell types on which earlier reports have been made.
