Females of Haliphron atlanticus are very large, reaching 400 mm ML or a total length up to 2m (Nesis, 1982). Body tissues are gelatinous; the mantle is short and broad and the head wide; the eyes are large and the short arms have a deep web. The funnel is embedded in head tissue. Males are much smaller than females but are relatively large (ca. 300 mm total length) for an argonautoid. The hectocotylus develops in an inconspicuous sac in front of the right eye which gives the male the appearance of having only seven arms. The hectocotylus detaches at mating. Females brood their eggs, which are attached to the oral side of the arm bases near the mouth (Young, 1995).
This species is widely distributed from tropical to high latitudes and occupies meso- to bathypelagic depths. It is commonly associated with slopes of land masses. The habitat of this octopod is unusual. It has been captured in bottom trawls and videotaped swimming within centimeters of the ocean floor (brooding female) suggesting a benthopelagic habitat along the slope. However, it has also been taken from the open ocean thousands of meters from the ocean floor and hundreds of miles from the nearest slope.
– from Tree of Life web project on haliphron atlanticus:
Also, animations of the beast swimming in its deep sea void: http://www.mnh.si.edu/cephs/young92/cephs6.html
Alabaster pale, blood drained white,
gelatinous mayonaise flesh
held together by tissue mesh,
drifting alone above stygian sludge.