‘Biological Searchlight’: World’s Largest Glowing Vertebrate May Use Its Light to Hunt Prey
A shark... with headlights?
“`html
Scientists have discovered that the kitefin shark, the world’s largest bioluminescent vertebrate, likely uses its glow in a novel way compared to other deep-sea creatures. Rather than relying solely on its light for camouflage, researchers led by marine biologist Julien Claes believe the shark may deploy its bioluminescence as a hunting tool, similar to a searchlight illuminating the ocean floor.
Most bioluminescent animals in the ocean use their light through counterillumination, a camouflage technique where creatures glow to match the faint light filtering from above, helping them blend in rather than cast a visible shadow. The kitefin shark’s belly does produce this type of light, matching the bluish-green wavelengths found at depths where the species lives. However, the research team found something unexpected: the shark’s glow spreads sideways far more broadly than typical counterilluminating animals, with the strongest effect concentrated around its front.
This unusual light distribution pattern suggests the kitefin shark uses its glow to illuminate prey in the otherwise pitch-black deep ocean. The finding becomes more intriguing when considering the shark’s hunting challenges—it swims at just 13 centimeters per second, making it the slowest shark on record, yet pursues fast-moving prey like lanternsharks and cephalopods. The dual-purpose glow strategy, combining downward camouflage with sideways illumination, could explain how this sluggish predator successfully hunts in the dark depths.
“`
Originally reported by Sciencealert →
About the Author
