Fish and Squid | Polar Unbound


The colossal squid, sometimes called the Antarctic squid, is thought to be the largest
species of squid in the world. Relatively little is known about this species and what is known
has been gleaned from only a few specimens. Analysis of the smaller, immature specimens
estimate that they can grow as large as 40 feet long and weigh around 1,700 pounds. The squid’s arms are lined with sharp hooks to aid with capturing prey. Further, the colossal squid has the largest eyes in the animal kingdom, measuring 12 to 16 inches across. These eyes are thought to be used for predator detection rather than for hunting due to the fact that it ingests around an ounce of food a day. It’s small food intake is due to its relatively slow metabolism.

The colossal squid is thought to range at a depth of around 7,200 feet, though immature specimens can only reach depths of 3,200 feet. Juveniles are preyed upon by many types of animals, including sperm whales and southern elephant seals. However, only sperm whales and sleeper sharks are capable of taking down an adult.


Mackerel icefish belong to a group of “white-blooded” fishes—fishes that can survive without red oxygen carrying pigment hemoglobin in their blood cells. Thus, their blood isn’t necessarily “white,” but colorless.  They can largely be found around Iles Kerguelen, Heard and McDonald Islands and South Georgia. They are a significant food source for seals, marine birds and other larger fish. 


The Antarctic toothfish and the Patagonian toothfish can be found in the Antarctic region. While the Antarctic toothfish is found at high altitudes closer to the Antarctic continent, the Patagonian toothfish is largely found in subantarctic waters—particularly around island shelves and submarine banks. 

FUN FACT: The Antarctic toothfish, unlike the Patagonian toothfish, has antifreeze proteins within its blood and tissues as the seawater is below the tissue’s normal freezing point. 


Antarctic cods, an abundant fish, aren’t actually true cods. Antarctic cods are another Antarctic fish whose blood contains antifreeze as a way to prevent it from freezing in the frigid temperatures.