Invertebrates
Bigfin Squid
Magnapinna · also called long-armed squid
Trailing ten impossibly long arms bent at sharp right angles beneath a small, unassuming body, a bigfin squid drifts through the deep sea in a posture unlike anything else known to science, rarely observed except through the cameras of deep-diving submersibles.
Overview
The bigfin squid, genus Magnapinna, is a long-armed deep-sea cephalopod native to deep ocean habitat recorded across every major ocean basin. Its extraordinarily long, right-angled arms, rarely observed natural behaviour, and status as one of the most visually striking deep-sea video subjects make it one of the most enigmatic cephalopods found anywhere in the ocean.
An arm posture unlike any other cephalopod
While many deep-sea squid have unusual body proportions, the bigfin squid’s habit of holding its extraordinarily long arms bent sharply at a right angle remains one of the most distinctive and least understood postures documented in any cephalopod, captured only rarely on deep-sea camera footage.
Status
Not Evaluated, with population trends almost entirely unknown given how rarely this genus has ever been directly observed.
Bigfin Squid: common questions
Why is the bigfin squid so unusual looking?
This genus has ten arms of remarkably similar length, each far longer relative to its body than the arms of most other squid species, and holds them bent at a sharp right angle partway along their length, a posture not seen in most other cephalopods.
How does the bigfin squid catch its food?
Some researchers believe this genus may drift with its long arms trailing below it like fishing lines, brushing along the seafloor or through the water column to detect prey, though its exact feeding behaviour remains poorly documented.
Why is so little known about the bigfin squid?
This genus is rarely observed directly, with most scientific knowledge coming from footage captured by deep-sea submersibles and remotely operated vehicles, since intact specimens are almost never recovered for direct study.
Is the bigfin squid's body as large as its arms suggest?
No, this genus has a relatively small, gelatinous main body compared with the extraordinary length of its trailing arms, which make up the vast majority of the animal's overall length.