The Flapjack Octopus, belonging to the genus Opisthoteuthis, is a deep-sea cephalopod recognizable by its umbrella-like, flattened appearance and gelatinous body texture. It is often affectionately called a “Dumbo Octopus” due to the prominent, ear-like fins above its eyes. Unlike octopuses of shallower waters, the Flapjack Octopus is classified as a cirrate octopus, distinguished by the webbing that joins its eight arms.
Habitat and Ecological Niche
This genus of octopus inhabits the cold, dark waters of the bathyal zone, typically residing on or just above the seafloor, a lifestyle known as benthic. While the precise depth range varies, they are often found between 500 and 1,500 meters, though some sightings have occurred as deep as 2,350 meters. The immense pressure and near-freezing temperatures of this deep-sea environment require specialized biological adaptations.
The Flapjack Octopus possesses a gelatinous body structure, which helps it maintain buoyancy and withstand the crushing pressure of its habitat. It lacks an ink sac, a defensive tool useless in the perpetually dark abyss. Its fins are used for slow, controlled movement, helping it drift and hover near the nutrient-poor seabed where it seeks its meals.
Primary Food Sources
The diet of the Flapjack Octopus is highly specialized, consisting primarily of small, slow-moving invertebrates found in the benthic zone. Analyzing the stomach contents of captured specimens has revealed a menu rich in tiny, soft-bodied organisms that live in the sediment. These prey items are generally not fast enough to escape the octopus’s methodical hunting style.
The staple of its diet includes various small crustaceans and polychaete worms (bristle worms). Crustaceans often consumed include:
- Copepods
- Amphipods
- Mysids
- Tiny shrimp
The octopus targets these small, easily consumed organisms, which provide sufficient nutrition without requiring a high-speed chase or struggle, fitting its deep-ocean environment.
Unique Feeding Strategy
The method the Flapjack Octopus uses to capture and ingest its prey is distinct from the hunting techniques of many shallow-water octopuses. Instead of using a powerful beak to drill into shelled prey, this octopus is adapted to consume soft-bodied organisms whole. Its arms are lined not only with suckers but also with small, finger-like filaments called cirri, which play a role in sensing and moving food.
The extensive webbing between its arms can be spread out like an umbrella, which researchers believe is used to trap or guide tiny organisms toward its mouth. The octopus may also probe the seafloor with its arms or flap its webbed structure to stir up sediment, revealing hidden worms and crustaceans. Once prey is secured, the cirri and suckers work together to transport the small, soft-bodied meal toward the mouth for immediate engulfment, a streamlined, low-energy feeding process well-suited to its deep-sea lifestyle.