Chromatophores

Abstract

Summary. Chromatophores, the parts concerned with the colour changes in animals, are best developed in the cephalopods, the crustaceans, and the three lower classes of vertebrates, the fishes, amphibians, and reptiles. In the cephalopods chromato‐ phores are really diminutive organs in that each one consists of a central coloured cell which is expanded against its own elasticity by radial muscle fibres. In the crustaceans a cellular complex often with several colours makes up each chromato‐ phore. This expands and contracts slowly and thus changes the tint of the animal. In the vertebrates a coloured background in the skin is exposed to view or covered up by motile black pigment cells whose melanin granules are made to migrate within the containing cell. Most animals show relatively uniform changes of colour, but in a few, as, for instance, flat‐fishes, a pattern may be imitated showing that the central control of the chromatophore system must be somewhat differentiated in the direction in which the musculature is.

Color Changes in Fundulus with Special Reference to the Color Changes of the Iridosomes

“…This may be due to the less favorable condition of the material used in Cambridge, or to the fact that the fish studied at Woods Hole were observed through the summer months, during and after the breeding season. It has been noted by others (Parker;1930), that the color changes of fish called forth during the breeding season by the color of the background are much more pronounced than during the rest of the year. The humoral state of the body is undoubtedly very different during the breeding season, and this may place the iridosomes in a particularly reactive condition.…”

The colour change of the minnow, Phoxinus phoxinus with particular reference to the effect of spinal lesions

“…Research in the field of vertebrate colour changes has been reviewed extensively (Hogben, 1924; Parker, 1930Parker, , 1948Sand, 1935; Waring, 1942Waring, , 1963Fingerman, 1963 Melanophores are the most important chromatophores in the changes of tint in response to background differences in the minnow Phoxinusphoxinus L., (Hewer, 1926). In the minnow there are large macromelanophores and small micromelanophores, each type being both dermal and epidermal in distribution (Healey, 1951).…”