Seven-armed octopus

Appearance

The seven-arm octopus is so named because in males, the hectocotylus is coiled in a sac beneath the right eye. Due to this species' thick, gelatinous tissue, the arm is easily overlooked, giving the appearance of just seven arms. However, like other octopuses, it actually has eight.

Distribution

The type specimen of ''H. atlanticus'' was collected in the Atlantic Ocean at . It is deposited at the University of Copenhagen Zoological Museum.

Since then, several specimens have been caught throughout the Atlantic, as far as the Azores archipelago and near South Georgia Island.

In 2002, a single specimen of giant proportions was caught by fishermen trawling at a depth of 920 m off the eastern Chatham Rise, New Zealand. This specimen, the largest of this species and of all octopuses, was the first validated record of ''Haliphron'' from the South Pacific. It had a mantle length of 0.69 m , a total length of 2.90 m , and a weight of 61.0 kg , although it was incomplete.

Habitat

Isotopic, photographic and video evidence have shown complex interactions between ''H.atlanticus'' and jellyfish and other gelatinous zooplankton, from feeding to protection, respectively.