ULTRASTRUCTURE AND RESPONSE TO BACKGROUND ILLUMINATION OF MELANOPHORES OF ATLANTIC HAGFISH MYXINE GLUTINOSA L

The melanophores of the Atlantic hagfish, Myxine glutinosa, L. have been investigated by light and electron microscopical methods. Animals have also been illuminated against black or white backgrounds in an attempt to evoke color change. 1. 1. The melanophores have basically the same structure as other investigated melanophores in poikilothermic vertebrates, but differ in two respects: 1.1. (a) they have cytoplasmic tubules, 400-700 Å in diameter, 1.2. (b) they lack an inner membrane as described in Lebistes reticulatus. 2. 2. No color change was observed with the naked eye, nor did microscopy reveal any migration, fading, or other change in the melanophore due to the influence of light. 3. 3. The mortality observed in animals illuminated in white aquaria is discussed. © 1968.