Enteroctopus: The Giant Octopus
Southern red octopuses vary in color from bright red to rust and have whitish suckers under their arms. Their mantle is about 20 cm wide and has a rough appearance. The arm length for this species is approximately 60 cm. Each arm has numerous suckers (180 to 210) that occur in two rows, arms also have enlarged suckers closer to the mantle. The total body length from mantle to arm tip, on average, is 1 m. Average body mass of southern red octopuses is approximately 4 kg. The eyes of the adults are highly developed and large, 2.32 to 9.82 mm in diameter.
Hatchlings of the southern red octopus are 14.8 to 21.5 mm in total body length. Arm length ranges from 5.8 to 9.2mm, mantle size is 7 to 9.5 mm in length, and 5.3 to 8.8mm in width. Newly-hatched young are mostly colorless apart from the chromatophores on the mantel and arms. Along the arms the chromatophores are arranged in a linear fashion. On the mantel, the chromatophores are more spaced out.
Habitat & Diet
The Patagonian giant octopus or southern red octopus, Enteroctopus megalocyathus, is limited to the Neotropical region of southern South America. This species is found as far south as the southeastern Pacific coast of Chile, as far north as Rio de la Plata in Argentina, and around the coast of the Falkland Islands.
Southern red octopuses inhabit shallow sub-tidal zones of the Patagonian coast. They live in small caves and crevices at a depth of 5 to 140 m. The area around the den of the animals are usually littered by crab shells and occasionally the shells of bivalve mollusks.
They hunt at night, surviving primarily on shrimp, clams, lobsters, and fish, but have been known to attack and eat sharks as well as birds, using their sharp, beaklike mouths to puncture and tear flesh. They range throughout the temperate waters of the Pacific, from southern California to Alaska, west to the Aleutian Islands and Japan.
Southern red octopuses are motile and solitary creatures that spend most of their time in their dens and only leave to avoid predation, hunt for food, or mate. Unless mating, members of the same species are hostile towards each other and cannibalism can occur. This species exhibits timid behavior and as a result rarely interacts with humans. Southern red octopuses like other cephalopods have an ink sac that is used to avoid predators. They also have chromatophores that allow them to change their color to avoid predators by blending in with their environment. The chromatophores are also used to communicate with other members of this species over territory and mating.
Lifespan of southern red octopuses is primarily determined by when this species mates. The average lifespan of this species in the wild is similar to that of Enteroctopus dofleini, giant Pacific octopus, that live 3 to 5 years. Because southern red octopuses are cultured in captivity for food, the maximum lifespan of this species is never fully achieved in captivity.
Sourced From/More Information: Article 1: https://animaldiversity.org/accounts/Enteroctopus_megalocyathus/ Article 2 & Images: https://www.nationalgeographic.com/animals/invertebrates/facts/giant-pacific-octopus Images: https://inverts.wallawalla.edu/Mollusca/Cephalopoda/Enteroctopus_dofleini.html