How big are giant squids?

The Giant Squid (Architeuthis dux) and its colossal cousins, the Colossal Squid (Mesonychoteuthis hamiltoni), occupy a realm that remains largely unexplored by humans.

However, separating fact from fiction when it comes to the size of giant squids has proven to be a daunting task. Exaggerated reports and misinterpretations have clouded our understanding of these creatures, leaving us to question the true extent of their dimensions.

Unknown Giants

Giant squids (Architeuthis dux) live up to their name: one the largest verifiable giant squid ever recorded and confirmed by scientists was almost 43 feet (13 meters) long, and may have weighed nearly a ton. Despite their immense size, giant squids remain elusive creatures, rarely seen by humans. Most of what we know about these deep-sea giants comes from dead carcasses that washed up on beaches or were found by fishermen.

The elusiveness of the Architeuthis dux stems from a combination of factors deeply rooted in its biology and habitat. One of the primary reasons for its elusive nature is its preferred habitat in the deep ocean. This deep-sea environment, often beyond the reach of human exploration, makes direct observation and study of the giant squid challenging.

Giant squids are predominantly solitary creatures that inhabit vast expanses of the ocean, roaming at depths ranging from hundreds to thousands of meters. Their solitary lifestyle and vast range make encounters with these creatures rare and unpredictable. Giant squids are also highly adept at avoiding detection. They possess keen senses, including large eyes adapted to low-light conditions, which allow them to navigate the dark depths with precision while remaining vigilant for potential threats.

But in 2006, a groundbreaking discovery captivated the world: scientists from Japan’s National Science Museum filmed a giant squid for the first time. For the first time, people around the world were able to witness a living, breathing giant squid, unlocking new possibilities for scientific research and exploration.

Anatomy and Adaptations

At first glance, the giant squid may appear to have a simple body structure, but upon closer inspection, it reveals a remarkable array of adaptations that enable it to thrive in the dark depths of the ocean.

Arms

The giant squid boasts eight muscular arms, each adorned with rows of suckers lined with sharp, tooth-like structures. These suckers serve multiple functions, allowing the squid to grasp and manipulate prey with remarkable precision. The arms are also capable of regenerating if damaged, ensuring the squid maintains its hunting prowess.

At the center of the arms lies the squid’s beak, a sharp and powerful structure used for tearing and consuming prey. Once the prey is subdued, the arms guide it towards the beak, where it is efficiently processed into smaller, digestible pieces. This process is facilitated by the radula, a tongue-like organ covered in rows of teeth, located within the beak.

Tentacles

While the arms of the giant squid are formidable, it is the two elongated feeding tentacles that truly set it apart. These tentacles can extend up to 33 feet (10 meters) in length, doubling the total span of the squid. At the tips of these tentacles are hundreds of powerful, sharp-toothed suckers, capable of grasping prey from a considerable distance.

The feeding tentacles are deployed with remarkable speed and precision, shooting out to ensnare unsuspecting prey. Once captured, the prey is swiftly brought within reach of the arms and beak for consumption. This dual-armed approach allows the giant squid to overcome even the most elusive of prey in the dark depths of the ocean.

Eyes and Head

One of the most striking features of the giant squid is its eyes, which are the size of dinner plates—the largest in the animal kingdom. At almost 1 foot (30 centimeters) in diameter, these enormous eyes absorb more light than their smaller counterparts, allowing the squid to detect bioluminescent prey or potential predators lurking in the darkness. The squid’s complex brain, although tiny compared to its massive body, is shaped like a donut, with its esophagus running through the “donut hole.” This unique structure enables the squid to efficiently process food, grinding it into tiny bits before digestion.

Body and Funnel

The main part of the giant squid’s body, known as the mantle, houses all of its basic organs. Positioned on the body’s underside is the funnel, a multipurpose tool that the squid uses for various functions. By pumping water and other fluids through the funnel, the squid can exhale, expel waste, lay eggs, squirt ink, and propel itself through the water using jet propulsion. This ingenious adaptation allows the giant squid to navigate its underwater world with precision and agility.

Adaptations for Survival

In addition to its physical adaptations, the giant squid has evolved a range of behaviors that enhance its chances of survival in the deep ocean. With its ability to change skin color and texture in the blink of an eye, the squid can camouflage itself against its surroundings, avoiding detection by predators and prey alike. Furthermore, its rapid movements and powerful tentacles enable it to capture and subdue prey with remarkable efficiency, ensuring a steady supply of food in the harsh environment of the deep sea.

How Big and Strong are Giant Squids?

There are widespread reports of specimens exceeding staggering lengths of 18 meters (59 feet), but scientific documentation of such giants has been notably absent in recent times, despite the availability of hundreds of specimens for study.

Among the reported behemoths, the “Thimble Tickle specimen” documented by Verrill in 1880, measuring a reported 55 feet (16.76 meters), is often cited as the largest ever recorded. Similarly, a specimen described by Kirk in 1888, measuring 55 feet 2 inches (16.81 meters) or even 57 feet (17.37 meters), has stirred curiosity due to its peculiar proportions. However, it is now believed that these extraordinary lengths may have been the result of significant elongation of the feeding tentacles or inaccurate measurement techniques.

Drawing from a comprehensive dataset spanning 40 years and comprising over 50 giant squid specimens, giant squids span an average total length at maturity of 11 meters (36 feet), with a rare maximum length reaching 14–15 meters (46–49 feet).

When considering mantle length, there are reports of a maximum of 225 centimeters (7.38 feet) for females, to 279 centimeters (9.15 feet), albeit subject to scrutiny. The inclusion of head and arms but excluding tentacles rarely exceeds 5 meters (16 feet).

In terms of weight, the maximum for females is 275 kilograms (606 pounds) and for males 150 kilograms (330 pounds), with a potential maximum weight of up to 500 kilograms (1,100 pounds).

Notably, the giant squid possesses some of the largest eyes in the animal kingdom, rivaled only by its distant relative, the colossal squid. Historical accounts of “dinner plate–sized” eyes find support in modern measurements, with accepted diameters exceeding 27 centimeters (11 inches) and pupils reaching 9 centimeters (3.5 inches).

The Colossal Cousins

The colossal squid, known scientifically as Mesonychoteuthis hamiltoni, is the largest member of its family, the Cranchiidae, which includes glass squids. With its massive body and formidable appendages, the colossal squid cuts an imposing figure in the depths of the Southern Ocean. Unlike its more elusive relative, the giant squid, the colossal squid boasts a unique anatomy that sets it apart from other cephalopods.

One of the most striking features of the colossal squid is its eyes, which are the largest of any known creature. With an estimated diameter of 27–30 cm (11–12 in), these colossal orbs enable the squid to peer into the darkness of the deep sea with unparalleled clarity. Equipped with such impressive visual acuity, the colossal squid is able to spot prey and potential predators from great distances, giving it a significant advantage in the harsh environment of the ocean depths.

The colossal squid lives up to its name in more ways than one, boasting dimensions that rival even those of its giant counterpart. While the exact size of the colossal squid remains a subject of debate among scientists, specimens have been documented reaching lengths of up to 45 feet (14 meters) and weighing over half a ton.

More Than One Species of Giant Squid

While scientists have made significant strides in understanding these enigmatic creatures, many questions remain unanswered. One of the greatest mysteries surrounding giant squids is their taxonomic classification. Are there multiple species of giant squids, each with its own unique traits, or is there just one species swimming in the depths of the ocean? The answer to this question has profound implications for our understanding of giant squid diversity and evolution.

Despite their immense size, giant squids belong to the taxonomic order Oegopsina, which includes hundreds of other squid species. Within this order, giant squids are classified in the genus Architeuthis, derived from the Greek words for “chief squid.” Some researchers propose that there may be as many as 8 species within the genus Architeuthis, each adapted to its own unique ecological niche. However, due to the scarcity of specimens available for study, there is still much debate among scientists about the true diversity of giant squids.