Notice the red coloring to the tagged individual; this is from the Alizarin stain previously applied using a plastic bag that was removed just before this picture was taken. Even the green segments that are not obviously red are sufficiently stained to be detected later in the laboratory. After about a week, stained individuals are collected and returned to the laboratory for growth analysis. Each branch can produce a complete new segment each day, so growth of Halimeda can be prolific on a reef.