This vermilion star (Mediaster aequalis) really caught my eye when I noticed it nestled among a cluster of orange social tunicates. Sunlight contains all the visible light we see (red, orange, yellow, green, blue, violet) and appears white, but when sunlight penetrates into the ocean red light is the first to be absorbed with increased depth. The result is that what appears bright red to me (when illuminated by my dive light), appears blackish to other underwater creatures in natural light at that depth, and so it’s interesting that this bright sea star tends to disappear into the reef. The vermilion star can grow to 8 inches (20 cm) across, and has a range from northern Alaska to northern Mexico.
