User:Chris7M/Mesonychoteuthis hamiltoni

Vision
Unlike swordfish and other large pelagic species, the colossal squid (along with the giant squid) has eyes that are nearly 2–3 times the diameter of their deepsea counterparts. Further research suggests that colossal squid are able to see bioluminescence generated by large predators that disrupt plankton when they move. The colossal squid's eyes glow in the dark via long rectangularly shaped light-producing photophores located next to the lens on the front of both eyeballs. Symbiotic bacteria reside within these photophores and luminesce through chemical reaction. It is hypothesized that the colossal squid's eyes can detect predator movement beyond 120 m, which is the upper limit of the sperm whale's sonar range.

Feeding
Little is known about their behavior, but it is believed to feed on prey such as chaetognatha, large fish such as the Patagonian toothfish, and smaller squid in the deep ocean using bioluminescence. A recent study by Remeslo, Yakushev and Laptikhovsky revealed that Antarctic toothfish make up a significant part of the colossal squid's diet; of the 8,000 toothfish brought aboard trawlers between 2011 and 2014, seventy-one showed clear signs of attack by colossal squid. A study in Prydz Bay region of Antarctica found squid remains in a female colossal squid's stomach, suggesting the possibility of cannibalism within this species.