Fish
Kitefin Shark
Dalatias licha · also called seal shark
Believed to be the largest known glowing vertebrate on Earth, a kitefin shark lights up its entire underside in the deep sea, erasing its own silhouette to stay hidden from predators watching from below.
Overview
The kitefin shark, Dalatias licha, is a bioluminescent deep-sea shark native to deep ocean habitat recorded across temperate and tropical waters worldwide. Its record-setting status as the largest known luminous vertebrate, effective counter-illumination camouflage, and Vulnerable conservation status make it one of the more scientifically remarkable and conservation-relevant sharks found anywhere in the deep sea.
A giant among glowing animals
While many deep-sea sharks produce their own light on a small scale, the kitefin shark takes the strategy to an unusual extreme for its size, becoming the largest known glowing vertebrate and proving that bioluminescent camouflage can work even for a shark of considerable bulk.
Status
Vulnerable, with populations declining in parts of its range due to bycatch in deep-sea fisheries and limited by the species’ naturally slow reproduction.
Kitefin Shark: common questions
Why is the kitefin shark considered special among glowing animals?
This species is believed to be the largest known vertebrate capable of producing its own light, with light-producing organs covering much of its underside, making it stand out among the many smaller bioluminescent deep-sea sharks.
Why does the kitefin shark glow?
This species uses its glowing underside for counter-illumination, matching the faint light filtering down from the surface to make its silhouette harder for predators below to detect against the brighter water above.
How does the kitefin shark eat prey too large to swallow whole?
This species can capture prey both by suction and by biting and twisting to tear flesh from animals too large to swallow whole, a feeding technique shared with some of its close relatives.
How deep does the kitefin shark live?
This species is typically found at depths ranging from around 200 metres down to over 1,800 metres, well beyond where sunlight penetrates, making it a genuine deep-sea specialist.