Giant Pacific Octopus

Lore & Background

The giant Pacific octopus was first described in 1910 by Gerhard Wülker of Leipzig University in Über Japanische Cephalopoden. The specific name dofleini was chosen in honor of German scientist Franz Theodor Doflein. It was moved to genus Enteroctopus by Eric Hochberg in 1998. Adults usually weigh around 15 kg (33 lb), with an arm span up to 4.3 m (14 ft). The largest individual weighed in at 600 lb (270 kg), with a radial span of 32 ft (9.8 m). The largest suckers are about 6.4 cm (2.5 in) and can support 16 kg (35 lb) each. E. dofleini preys on shrimp, crabs, scallops, abalones, cockles, snails, clams, lobsters, fish, squid, other octopuses, and has been observed to catch spiny dogfish up to 1.2 m (4 ft) in captivity, with evidence of preying on small sharks in the wild. In May 2012, a wild giant Pacific octopus was photographed attacking and drowning a seagull. Predators include marine mammals such as harbor seals, sea otters, and sperm whales, as well as Pacific sleeper sharks. The octopus is also a significant source of protein for human consumption, with about 3.3 million tonnes commercially fished annually. It is parasitized by the mesozoan Dicyemodeca anthinocephalum, which lives in its renal appendages. E. dofleini move through open water using jet propulsion and crawl on the seafloor using their arms. They remain stationary or in hiding 94% of the time. They are den dwellers, and their dens range across depth and substratum type including caves, holes beneath rock, and trash on the ocean floor. The giant Pacific octopus has a lifespan of three to five years, reaching sexual maturity at one to two years of age. Females lay between 120,000 and 400,000 eggs, which are intensively cared for exclusively by the female, who dies soon after hatching. Hatchlings are about the size of a grain of rice, and their growth rate is rapid, starting from 0.03 g and growing to 20–40 kg at adulthood.

In Their Own Story

The current swept gently through the kelp forest as the octopus drifted, its mantle pulsing rhythmically. It paused before a cluster of barnacles, its skin instantly shifting from pale grey to a mottled brown, erasing its silhouette against the rock. A hermit crab scuttled nearby, unaware that it was being watched by three eyes and eight arms. With a sudden, fluid motion, the octopus lunged, enveloping the crab in a cloud of ink and a firm embrace. It retreated to its den, dragging its prize into the shadows, where the only light came from the bioluminescent dance of plankton filtering through the water.

Reader's Guide

The giant Pacific octopus is found in coastal North Pacific waters from Baja California north to Alaska and across to the Russian Far East, south to the East China Sea, Yellow Sea, Sea of Japan, Japan's Pacific east coast, and around the Korean Peninsula. It inhabits depths from the intertidal zone down to 2,000 m (6,600 ft), preferring colder, oxygen- and nutrient-rich waters. It is the largest octopus species. Its diet includes shrimp, crabs, scallops, abalones, cockles, snails, clams, lobsters, fish, squid, other octopuses, and occasionally small sharks and birds. It is preyed upon by harbor seals, sea otters, sperm whales, Pacific sleeper sharks, and humans. The octopus is a den dweller, often using caves, holes under rocks, or trash on the ocean floor. It is capable of jet propulsion and crawling. Its lifespan is three to five years. The conservation status according to the IUCN Red List is not addressed in the source article.

Did You Know?

• The giant Pacific octopus is the largest octopus species on earth.
• The largest individual on record weighed 600 lb (270 kg) with a radial span of 32 ft (9.8 m).
• A female giant Pacific octopus can lay between 120,000 and 400,000 eggs.
• The octopus has been observed preying on spiny dogfish sharks and even seagulls.