Exposure to sulfur-rich volcanic soil may increase production of pheomelanin, a pigment that gives a reddish tint to the feathers of barn owls living on remote volcanic islands Barn owls (Tyto alba) ...

There are many sulphur (yellow) butterflies in southern Florida and, lucky for us, they are present all year round. The most abundant of the sulphur butterflies are the orange barred sulphur, the ...

Purple bacteria also known as proteobacteria are phototrophic, capable of producing their own food via photosynthesis. They are pigmented with bacteriochlorophyll, together with various carotenoids, ...