The structure of the pigment cells in the turtle Trionyx sinensis.

Abstract

A light and transmission electron microscopic study of the pigment cells (chromatophores) revealed the presence of three types of cells, namely: melanophores, xanthophores or erythrophores, and iridophores. The melanophores contained eumelanin containing organelles, the melanosomes and iridophores showed reflecting platelets, whereas, the xanthophores contained pterinosomes. Quantitatively melanophores appeared in large numbers and were widely distributed, ranging from the skin to many internal viscera, whereas iridophores were few and xanthophores very rare.