Dendritic chromatophores that contained blue pigmentary organelles were found in the bluish parts of the skin of two callionymid species, the mandarin fish, Synchiropus splendidus, and the psychedelic fish, S. picturatus. We named these novel cells “cyanophores” and the organelles “cyanosomes”. In response to various stimulatory cues, the cyanophores responded by the aggregation or dispersion of cyanosomes. In addition to their role in the revelation of bluish hues, these cyanophores may participate in the changes in shades of blue of these gorgeous fish.