The frilled shark, a creature of the deep, is a mysterious inhabitant of the ocean’s depths. Its ancient lineage and unusual physical characteristics offer a glimpse into prehistoric marine life.
Discovering the Frilled Shark
The frilled shark, Chlamydoselachus anguineus, has an eel-like body, dark brown or gray, reaching up to 2 meters, with females generally larger. Its name comes from six pairs of fringed gill slits, the first extending across its throat like a collar. The shark’s head is broad and flattened, with a short, rounded snout. Unlike most sharks, its mouth is at the very front of its head.
Inside its wide mouth are approximately 300 needle-like teeth, arranged in multiple rows. Each tooth is three-pronged and recurved, designed for grasping rather than tearing. This species is a “living fossil” because its primitive traits have remained unchanged for millions of years, with its lineage dating back 80 to 150 million years.
Frilled sharks inhabit outer continental shelves and upper continental slopes across the Atlantic and Pacific Oceans. They are found near the ocean floor at depths from 120 to 1,280 meters, but can be observed as deep as 1,570 meters or, in regions like Japan’s Suruga Bay, as shallow as 50 to 200 meters. Their widespread but patchy distribution includes areas off Norway, Japan, Australia, New Zealand, the US coasts, Chile, and South Africa.
Behavior and Hunting Strategies
Despite its intimidating appearance, the frilled shark is non-aggressive toward humans. Its behavior focuses on hunting and energy conservation in its deep-sea environment. When encountered outside its natural habitat, such as after accidental capture, any snapping or thrashing is a defensive reaction to stress.
This species is an ambush predator, a strategy suited to the dimly lit depths where it resides. It uses its flexible, snake-like body to coil and then lunge forward with quick, sudden strikes at unsuspecting prey. The frilled shark can also use a unique method of creating negative pressure by closing its gill slits, effectively sucking prey into its mouth.
Its diet includes cephalopods like squid and octopus, but also other sharks and bony fish. The shark’s specialized teeth are effective at snagging slippery prey, which it often swallows whole, even if the prey is up to half its own body size. A large, oil-filled liver provides buoyancy, allowing the frilled shark to hover motionless, patiently waiting to strike.
Frilled Sharks and Human Interaction
Encounters between frilled sharks and humans are rare due to the shark’s deep-sea habitat. The first recorded observation in its natural environment did not occur until 2004.
Most human interactions result from accidental catches by deep-sea fishing trawlers, gillnets, or longlines. These sharks are sometimes caught at depths around 700 meters, which aligns with common trawling limits. There are virtually no recorded instances of frilled sharks showing aggression or posing a threat to humans in their natural environment. Any reported injuries to humans have been minor, such as scientists accidentally cutting themselves on the sharp teeth while handling captured specimens during research.