The megamouth shark, a creature of the deep sea, remains largely an enigma. Its existence was only confirmed relatively recently, adding a layer of mystery to this rarely observed marine animal. The limited number of encounters with this species contributes to its elusive reputation.
Understanding the Megamouth Shark
The megamouth shark, scientifically known as Megachasma pelagios, has a distinctive appearance with a large, bulbous head and a broad, rounded snout. Its most notable feature is a remarkably wide mouth, which can open to approximately 1.3 meters (4 feet). This shark typically measures between 4 to 5.5 meters (13 to 18 feet) in length, with a reported weight of up to 1,215 kg (2,679 lbs).
This deepwater species inhabits tropical and temperate oceans worldwide, ranging from just below the surface to depths of as much as 1,500 meters (4,920 feet). The first megamouth shark was discovered in 1976 near Hawaii when it became entangled in a United States Navy ship’s sea anchor. Since then, fewer than 300 specimens have been observed or caught globally, highlighting its extreme rarity.
Diet and Feeding Habits
The megamouth shark is classified as a filter feeder, a feeding strategy it shares with only two other shark species: the whale shark and basking shark. Its diet consists primarily of small organisms found in the water column. These include zooplankton such as krill, copepods, shrimp larvae, and small crustaceans like squat lobsters and crab larvae. It also consumes jellyfish.
The shark’s unique method of feeding involves swimming with its mouth open, filtering water to capture its prey. The interior of its gill slits are lined with finger-like structures called gill rakers that effectively trap these small food particles. While it has numerous rows of small teeth, they are not used for biting or tearing, serving instead as vestigial structures. A bright white band on its upper jaw might reflect light, potentially acting as a lure for planktonic prey in the dark depths where it resides.
Human Interactions and Threat Level
Megamouth sharks pose no threat to humans. Their diet, consisting solely of microscopic plankton and small invertebrates, means they have no interest in larger prey, including people. The feeding mechanism of filtering water does not involve hunting or aggressive behaviors.
Encounters between megamouth sharks and humans are exceedingly rare due to the shark’s deep-sea habitat and shy nature. They typically spend their days at depths of several hundred meters and migrate closer to the surface at night, following the vertical movements of their planktonic food source. Most recorded interactions have been accidental, often involving sharks caught as bycatch in fishing nets or observed during scientific research. There are no documented instances of megamouth sharks attacking or harming humans.