The Angular Roughshark: A Unique Deep-Sea Predator
The angular roughshark is one of the most unusual and mysterious sharks in the ocean. Found in the deep waters of the eastern Atlantic and Mediterranean Sea, this slow-moving shark is known for its odd appearance, elusive nature, and surprising ability to make a noise when caught.
A Distinctive Look
The Angular roughshark (Oxynotus centrina) stands out with its unique, angular body shape that is unlike any other shark. Its body has a distinctive humped, almost pyramid-like appearance due to its high, triangular dorsal fins and compressed, thickset torso. The first dorsal fin, located just behind the head, is particularly tall and prominent, while the second is slightly smaller. These large fins give the shark its sharp-edged, almost boxy profile, which contrasts with the streamlined bodies of most other sharks.
This species also has rough, spiky skin covered in thorn-like dermal denticles, giving it a gritty texture that serves as protection. Its colouration ranges from dark gray to brown, which helps it blend in with the murky depths of the ocean. The shark’s broad, flat head has small eyes, a blunt snout, and a mouth full of sharp, narrow teeth designed for grasping small prey.
Growing to about 1.5 meters (5 feet) in length, the Angular roughshark is a relatively small shark. Its slow, almost sluggish movements match its strange shape.
A Noisy Catch
One of the most fascinating behaviours of the Angular roughshark is the way it makes a sound when it is brought to the surface by fishers. It produces a low, grunting noise, possibly due to the release of air or water from its body. The exact reason for this sound isn’t fully understood, but it’s another quirk that makes this species stand out in the shark world.
Deep-Sea Dweller
The Angular roughshark inhabits deep waters, typically found between 60 and 660 meters (200 to 2,200 feet) below the surface. It prefers the soft, muddy ocean floor, where it moves slowly in search of food. Unlike faster sharks, this species is adapted for a more relaxed lifestyle, using its sluggish movements to surprise its prey.
Diet and Behaviour
This shark's diet consists mainly of bottom-dwelling creatures, such as small fish, squid, and crustaceans. Its sharp, specialized teeth allow it to grasp and crush its food. The Angular roughshark’s slow swimming is perfect for its hunting strategy, for it ambushes, rather than chases, its prey.
Despite its rough exterior and toothy grin, the Angular roughshark poses no threat to humans and is a rare sight due to its deep-sea habitat and rarity.
Conservation Status
Sadly, the Angular roughshark is classified as "Vulnerable" on the International Union for Conservation of Nature (IUCN) Red List. This species faces numerous threats from human activities, particularly deep-sea trawling, which can destroy its habitat and severely impact its food sources. Due to its slow reproductive rate, it is especially sensitive to overfishing and environmental changes.
A Mysterious Shark
Though its strange appearance and ability to "grunt" when caught make the Angular roughshark stand out, much about this species remains a mystery. Ongoing research seeks to understand more about its role in the deep-sea ecosystems and its unique adaptations to life in the depths. As attention to deep-sea conservation grows, protecting species like the Angular roughshark will be essential to maintaining the balance of ocean ecosystems.
