Bigfin squid are among the ocean’s most enigmatic and visually striking inhabitants, dwelling in the dark, crushing depths of the deep sea. Their unique appearance and the mystery surrounding their lives captivate scientists and the public, making their true dimensions a subject of widespread fascination.
Understanding Their True Dimensions
The bigfin squid (genus Magnapinna) is renowned for its extraordinary length, primarily due to its elongated arm and tentacle filaments. While the main body, or mantle, typically measures 30 to 60 centimeters (11.8 to 23.6 inches), their total length can be vastly greater. The longest observed bigfin squid reached 6.4 meters (21 feet), with its arms and tentacles accounting for 6.1 meters (20 feet) of that length. Their appendages can be up to 20 times longer than their mantle. Estimates suggest some specimens could exceed 8 meters (25 feet), with projections up to 12 meters (40 feet).
Unraveling Deep-Sea Measurement
Accurately measuring deep-sea creatures like the bigfin squid presents significant scientific hurdles. Researchers primarily rely on advanced technology such as Remotely Operated Vehicles (ROVs) and submersibles to capture rare video footage. These vehicles often employ specialized techniques, such as parallel lasers, to provide a scale for measurement from the video. Scientists might also estimate size by comparing the squid to objects of known dimensions present in the footage.
Despite these tools, challenges persist in the deep-sea environment. The extreme pressure, perpetual darkness, and limited observation time make it difficult to obtain clear, full views of a living specimen. The bigfin squid’s elusive nature and its tendency to remain partially obscured further complicate efforts. Consequently, most reported measurements are estimates derived from visual data, rather than direct physical measurements.
The Illusion of Immense Proportions
The perception of the bigfin squid’s large size stems largely from its unique body plan, which creates a visual effect. Unlike many other squid species, the bigfin squid possesses disproportionately long and thin arm and tentacle filaments. These appendages extend far beyond its relatively small mantle, often described as having “elbows” due to their distinctive bends. These filaments are held perpendicular to the body, contributing to their unusual appearance.
These spaghetti-like filaments trail for many meters, creating an optical illusion of large overall size. This contrasts sharply with other squid where arms are typically shorter and more robust in proportion to the main body. The perceived size of the bigfin squid is thus primarily a function of these extended, slender appendages, rather than a massive body mass or bulky mantle.
A Glimpse into Their Mysterious Lives
Bigfin squid inhabit the depths of the global ocean, including abyssal and hadal zones, making them the deepest-dwelling squid known. They have been documented at depths reaching 6,212 meters (20,381 feet). Sightings of these creatures are rare, with only about a dozen confirmed observations worldwide. Little is known about their feeding behavior, but scientists speculate they may use their long, sticky filaments, which are covered in microscopic suckers, to passively trap prey that drifts into them or to trawl the seafloor.