Instant Guide

Why giant squids have enormous eyes

The tentacled invertebrate boasts the largest eyes of any known animal — a trait scientists are crediting to an age-old, deep-sea foe

The disproportionately large eyes of the giant squid have long been one of the creature's more confounding attributes. And now, researchers are positing that the unusually large eyeballs are an evolutionary response to one of the invertebrate's most long-standing enemies — the fearsome sperm whale. Read on: 

How large are these eyes?
The squid's eyes can be the size of basketballs — larger than those of any known animal — and the creature itself can grow up to 46 feet long and weigh as much as five adult men. Similarly sized animals, such as whales and swordfish, have eyeballs that max out at just 3 inches in diameter.

And what did researchers discover?
That the eyes are not only unusually large, but surprisingly precise. A new study, published in the journal Current Biology, explains that the colossal squid's eyes are capable of taking in much more light than the eyes of other large sea creatures. The team thinks this may be an evolutionary response to the squid's main predator, the sperm whale.

Why is that?
Giant squids, which typically live a dim existence 2,000 feet under the ocean's surface, comprise three-fourths of the sperm whale's diet. The sperm whale uses loud clicks, or sonar, to find prey, and the squid is deaf. The theory goes that a squid with superior light-collecting eyes is able to detect faint bioluminescence from tiny plankton disrupted by approaching whales, "and use its jet propulsion to make a quick escape," says Nell Greenfieldboyce at NPR. The bigger its eyes, the more likely a squid is to survive and pass along its genes — which, over many, many generations, resulted in today's squids with enormous eyes.

Sources: Fox News, NPR, The State Column, Wired 

Recommended

Can the U.S. stop Chinese cyberattacks?
A picture of a computer with code and a Chinese flag in the background
Today's big question

Can the U.S. stop Chinese cyberattacks?

China plans to land astronaut on the moon by 2030, official says
Chinese astronauts Gui Haichao, Jing Haipeng and Zhu Yangzhu
race to the moon

China plans to land astronaut on the moon by 2030, official says

South Korean man facing prison time after opening airplane door in midair
An Asiana Airlines flight that had its emergency door opened midair.
Problems in the Sky

South Korean man facing prison time after opening airplane door in midair

Recep Tayyip Erdogan wins reelection in Turkey
Turkish President Recep Tayyip Erdogan.
Emerging Victorious

Recep Tayyip Erdogan wins reelection in Turkey

Most Popular

Disney hits back against DeSantis
Entranceway to Walt Disney World.
Feature

Disney hits back against DeSantis

What the shifting religious landscape means for American politics
Ballot box
Talking point

What the shifting religious landscape means for American politics

Censoring ideas and rewriting history
Copies of banned books from various states and school systems.
Briefing

Censoring ideas and rewriting history