|MadSci Network: Cell Biology|
Chromatophores are not independent, free-living organisms, which might explain why it's been difficult to find info. regarding their diet & lifespan. However, there are also several very different types of chromatophores that exist within a variety of different organisms, which could certainly lead to confusion over their exact function(s), as well.
The most widely known type of chromatophore is the pigment cells of cold-blooded animals, including amphibians, fish, reptiles, crustaceans, and cephalopods, some of which can amazingly change their color by expansion or contraction. An excellent illustration of a Cephalopod Chromatophore (i.e. from octopuses, squids, and cuttlefish) is found in the Tree of Life Web Project.
Chromatophores generally known as melanocytes are also present as pigment cells in warm-blooded mammals and birds, but they cannot alter their pigmentation through expansion or contraction.
Within plant cells, small pigment-bearing organelles known as plastids (e.g. chromoplasts & chloroplasts) can also be referred to as chromatophores.
Finally, even smaller, pigment-bearing, primarily
photosynthetic granules, within certain phototrophic bacteria,
are also known as chromatophores.
I'm not sure whether this info. will actually answer your question or not, but it might at least help to explain the reasons for your confusion. Thanks for the great question,
Jeff Buzby, Ph.D.
CHOC Research Institute
MadSci Cell Biology Network
Try the links in the MadSci Library for more information on Cell Biology.