Biliverdin - in Non-human Animals

In Non-human Animals

Biliverdin is an important component of avian egg shells. There is a significantly higher concentration of biliverdin in blue egg shells than in brown egg shells. Research has shown that the biliverdin of egg shells is produced from the shell gland, rather than from the breakdown of erythrocytes in the blood stream. The presence of biliverdin in egg shells may be an indicator of female fitness, and therefore likely demonstrates evolutionary significance.

Along with its presence in avian egg shells, other studies have also shown that biliverdin is present in the blue-green blood of many marine fish, the blood of tobacco hornworm, the wings of moth and butterfly, the serum and eggs of frogs, and the placenta of dogs. In the garfish (Belone belone) and related species, the bones are bright green because of biliverdin.

Biliverdin is also present in the green blood, muscles, bones, and mucosal lining of skinks of the genus Prasinohaema, found in New Guinea. It is uncertain whether this presence of biliverdin is an ecological or physiological adaptation of any kind. It has been suggested that accumulation of biliverdin might deter harmful infection by Plasmodium malaria parasites, though no statistically significant correlation has been established. The Cambodian frog, Chiromantis samkosensis also exhibits this character along with turquoise bones.