TYROSINASE ACTIVITY OF MELANIN AND PTERIDINE GRANULES IN GOLDFISH CHROMATOPHORES

1. 1. The melanin granules within the melanophore and the pteridine granules within the erythrophore in the adult skin of four colored varieties (black moor, red, white and calico) of goldfish, Carassius auratus L were separated by the method of low-speed density gradient centrifugation. 2. 2. It has been demonstrated that the melanin granules are free of tyrosinase activity and probably of pteridine derivatives and that the pteridine granules are the carriers of pteridine derivatives and tyrosinase. 3. 3. The location of tyrosinase has been demonstrated morphologically: (1) the melanization of erythrophores has been induced; (2) further melanization did not occur in the melanophores; (3) no amelanotic melanophores have been observed. © 1969.