#alloposidae

[herpsandbirds]

Seven-arm Octopus (Haliphron atlanticus), family Alloposidae, Salish Sea off the coast of WA, USA

This is one of the largest octopus species, with an estimated total length of 3.5 meters (11 feet) and a mass of 75 kg (165 lb)

This octopus does have 8 arms, but the hectocotylus (a specially modified arm used in egg fertilization) is coiled in a sac beneath the right eye, and is not easily seen.

This species is rarely seen by humans.

photographs by Eric Askilsrud (scuba.eric_⁠)

[uncharismatic-fauna]

Uncharismatic Fact of the Day

How many arms does the seven-arm octopus have? Despite it's name, this species (like all octopi) has eight! The eighth 'arm' is actually modified appendage called a hectocotylus that males use to fertilize the eggs of females. The hectocotylus is typically keept coiled in a sac under the males' right eye, making it easy to overlook when counting their arms.

(Image: A female seven-arm octopus (Haliphron atlanticus) by the Schmidt Ocean Institute)

If you send me proof that you’ve made a donation to UNRWA or another organization benefiting Palestinians, I’ll make art of any animal of your choosing.

[herpsandbirds]

Seven-arm Octopus (Haliphron atlanticus), family Alloposidae, off the West Coast of the United States

This is one of the largest octopus species, with an estimated total length of 3.5 meters (11 feet) and a mass of 75 kg (165 lb)

This octopus does have 8 arms, but the hectocotylus (a specially modified arm used in egg fertilization) is coiled in a sac beneath the right eye, and is not easily seen.

This species is rarely seen by humans.

During a research expedition with the remotely operated vehicle (ROV) Ventana in Monterey Bay last month, Senior Scientist Steven Haddock and researchers from MBARI’s Biodiversity and Biooptics Team happened upon a rare sight approximately 700 meters (2,300 feet) deep: a seven-arm octopus (Haliphron atlanticus). This sighting marked just our fourth observation of this species in nearly four decades of ocean exploration. Using a 4K camera specially developed by MBARI engineers for deep-sea exploration, the team collected detailed observations of the animal’s appearance and behavior. This extraordinary octopus was clutching a crimson red helmet jelly (Periphylla periphylla). Previous research by Haddock and MBARI collaborator Henk-Jan Hoving first revealed that this large deep-sea octopus feeds on gelatinous animals. This new sighting underscores the complexity of deep-sea food webs and their surprising connections.

video: MBARI (Monterey Bay Aquarium Research Institute)

[herpsandbirds]

Seven-arm Octopus (Haliphron atlanticus), family Alloposidae, in the deep sea of the coast of southern California, USA

This is one of the largest octopus species, with an estimated total length of 3.5 meters (11 feet) and a mass of 75 kg (165 lb)

This octopus does have 8 arms, but the hectocotylus (a specially modified arm used in egg fertilization) is coiled in a sac beneath the right eye, and is not easily seen.

This species is rarely seen by humans.

photographs via: Schmidt Ocean Institute