The scientists discovered the secret while taking pictures of fluorescent coral off of Little Cayman Island for a bioluminescence exhibition at the museum. A glowing green eel made an appearance at the photo shoot. When the team went looking for more on a subsequent expedition to the Bahamas and Solomon Islands, they were not disappointed. Sharks, rays, eels, lizardfish and other species were all glowing.
The team reported 180 species with the capability in the journal PLOS ONE on Jan. 8. Because many of these species also have yellow filters in their eyes that could allow them to see biofluorescence, the scientists suspect the animals are using the glow to stand out and communicate to each other, while remaining hidden from predators.