The question of whether sharks prey on anglerfish in the deep ocean depends largely on location and species overlap. Sharks are diverse cartilaginous fish, most of which inhabit sunlit surface waters, while anglerfish live in the pitch-black abyss. This interaction is uncommon, but it does occur due to a few exceptional shark species that have adapted to the deep-sea environment. Anglerfish are not a principal food source for any known shark species, but occasional predation is possible.
Deep-Sea Habitat Separation
The vast majority of shark species, including coastal and pelagic types, live in the epipelagic zone, which extends from the surface down to about 200 meters. This zone is warm, well-lit, and supports high levels of biomass. The main barrier preventing these sharks from encountering anglerfish is the extreme environmental shift that occurs below this layer.
Anglerfish of the suborder Ceratioidei live primarily in the bathypelagic zone, often called the midnight zone, which begins around 1,000 meters and can extend to 4,000 meters. Physical conditions at this depth are punishing, characterized by a constant, chilling temperature near 4°C and hydrostatic pressure that can reach hundreds of atmospheres. Most sharks lack the physiological adaptations necessary to handle this pressure and the metabolic demands of such cold, dark water, effectively separating the two groups.
Shark Species That Hunt the Abyss
A small number of specialized sharks, mostly from the family Somniosidae, are adapted to hunt in or traverse the deep ocean layers where anglerfish live. These sleeper sharks, including the Greenland and Pacific sleeper sharks, possess unique biological traits allowing them to survive in the mesopelagic and bathypelagic zones. Their sluggish movement is enabled by a low-energy lifestyle; the Greenland shark, for instance, cruises at approximately 0.34 meters per second.
These sharks rely on an oversized, oil-filled liver containing low-density squalene for buoyancy, compensating for their lack of a swim bladder. Their tissues also contain high concentrations of compounds like Trimethylamine N-oxide (TMAO) and urea, which stabilize proteins against the cold and immense pressure. Their hunting strategy is opportunistic, relying on scavenging and ambushing slow-moving prey.
Anglerfish as Prey: A Rare Occurrence
Deep-dwelling sharks have the capacity to consume anglerfish, but this fish is an incidental rather than a targeted food source. Anglerfish are ambush predators that drift in the water column, relying on their bioluminescent lure to attract prey, making them stationary and difficult to locate. Furthermore, the low biomass density of the bathypelagic zone means individual anglerfish are rare and widely dispersed, making them an inefficient target for active pursuit.
The body composition of deep-sea anglerfish also makes them a poor caloric reward for a large shark. They have a blobby, non-hydrodynamic structure with a high water content, sometimes up to 95 percent of their body mass, which significantly reduces their nutritional value.
The average size of a deep-sea anglerfish is only about six inches, making them a small meal even for a massive sleeper shark. Predation on anglerfish is therefore categorized as an occasional, opportunistic event when one crosses the path of a deep-sea shark.