Phycoerythrin is a red pigment found in certain algae, particularly in the group known as red algae. It plays a crucial role in photosynthesis by capturing light energy, especially in deep or murky waters where light is limited. This pigment absorbs light in the blue and green wavelengths, allowing the algae to thrive in various aquatic environments. In addition to its role in photosynthesis, phycoerythrin is used in various applications, including fluorescent microscopy and biomedical research. Its bright fluorescence makes it a valuable marker for detecting specific proteins and cells in laboratory settings, enhancing the study of biological processes.