Through the enduring process of evolution, the Humboldt squid has ended up with several fascinating adaptations that have led to its success in the ocean.

Nervous System- Neurological axons in Humboldt squid can be up to 1 mm in length. This comparably huge axon allows the neurological signals to work very fast ( Much like how a larger cable conducts more electricity, a larger axon will elicit increased conduction in the Humboldt squid’s brain. The evolution of larger axons in its brain has allowed for an increased action potential. This translates to D. gigas being able to do things like fleeing from predators or catching prey even faster. With this incredible adaptation the Red Devil can become a smarter and faster predator of the animal world.

Vertical Daily Migration- As revealed in several studies using electronic tagging, D. gigas spend the majority of their day in deep waters greater than 250 meters. This is approximately what scientists have named the hypoxic zone, where levels of oxygen are very low (Gilly et al. 2006).  When daylight fades, the squids rise together into higher oxygen saturated areas and feed upon unsuspecting prey such as lanternfish. What is truly interesting is that the Humboldt squid is doing most of its foraging in this Hypoxic zone where there is less than 5% oxygen levels. D. gigas has adapted its physiology to suppress oxygen consumption up to 90% and slow metabolism during its descent into the hypoxic zone. The exact physiological and biochemical adaptations remain a mystery and further research into this incredible evolutionary path is needed.

Tentacles- Each of the Humboldt squid’s tentacles are lined with suckers designed to grab and hold on to their prey. This adaptation is used primarily for hunting and subduing other animals in order for consumption. Humboldt squid are constantly eating, they live for on average a year and grow to up to five feet in length. D. gigas grows at an astonishing rate throughout their relatively short life. Their tentacles have adapted to assist this high growth rate by facilitating the catching of various animals.

Beak- After being entangled within the web of tentacles, D. gigas has an equally fearsome beak structure designed especially for ripping apart and swallowing flesh. This beak is made out of very hard calcium carbonate and positioned for efficient feeding potential. Paired with the long, muscular tentacles, these adaptations make Dosidicus gigas into a fearsome marine predator.

Chromatophores- The ability to camouflage oneself is a very useful adaptation in the wild. This skill can both help catch meals and keep from becoming one. The Humboldt squid have pigment-containing organelles called chromatophores that allow it to change color rapidly. This color change brought on by the chromatophores can be used to hide from predators and prey, or be used as a means of communication between squid ( Humboldts have most notably been seen to undergo metachrosis (changing colors by the expansion of pigment cells) when hunting or stressed (  As we can see from this video, metachrosis in Dosidicus gigas can definitely be brought on by a stress response.

Eye- Dosidicus gigas has a very interesting adaptations in their eye(video). They have exceptional underwater vision, which has allowed them to become a fearsome predator. Much like other squid, Dosidicus gigas has an eye like a camera that is characterized by having a spherical lens that focuses an image onto the squid’s retina (Sweeney et al., 2007). The Humboldt squid is a Coleoid and this group has an eye with the ability to form images in a variety of light conditions. They have ocular adaptations that include a variable pupil aperture that helps the eye respond so quickly to different surroundings (McCormick and Cohen, 2011).  The Humboldt squid’s eye is comparatively very large because of its increased size. With this larger eye comes an equally large retina and pupil structures that allow for increased light and a better quality image.

A suitable description of D. gigas comes from a very prominent figure in their study, William Gilly. “I find their adaptability and their perfection in dealing with anything nature throws at them to be a remarkable feature. They’re able to explore and take advantage of new environments that are compromised in any way.”

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