Phycobilins are water-soluble pigments found in certain algae, particularly in the groups known as cyanobacteria and red algae. They play a crucial role in photosynthesis by capturing light energy and transferring it to chlorophyll, allowing these organisms to thrive in various aquatic environments. These pigments are categorized into two main types: phycoerythrin, which absorbs green light and gives red algae their characteristic color, and phycocyanin, which absorbs orange and red light. The presence of phycobilins enables these algae to utilize light wavelengths that are less accessible to other photosynthetic organisms.