In the depth of the sea there are luring lights and twinkling eyestext_fields
New York: Squids that live hundreds of metres underwater are born with two identical eyes—does that mean they have something special about them?
Yes, indeed, says a report in The Guardian. Their mismatched eyes focus on two different worlds: one turn to the surface of the ocean while the other scan the sunless dark of the depth, according to the report.
Despite having identical eyes, squid’s left eyeball grows faster forming ‘a long tube’ that often comes with ‘a bright yellow lens’.
The huge sensitive eye helps the animal look for silhouettes of food or enemies that float overhead.
The left eyeball, which is half the diameter of the other, helps it scan ‘flashes of glowing animals against the dark waters below’.
Jon Ablett, senior curator of molluscs at the Natural History Museum in London said the animal’s eyes help it ‘exploit and inhabit’ two different environments.
The squid that scientists caught around the Atlantic islands of Ascension and Saint Helena, reportedly, proved its name, jewel squid, true.
When an ultraviolet torch shined on it, the animal’s body ‘twinkled all over in ruby red spots’.
“When you get within about 15cm suddenly everything glows red, and the closer you go, the stronger the colour is,” says James Maclaine, senior curator of fish at the Natural History Museum, was quoted as saying.
Squid’s red dots, according to the report, are light-emitting organs called photophores that glows blue when they swim underwater. They don’t glow red as there are no UV light out there in the depth.
The cockeye squid (Histioteuthis heteropsis) may also use photophores to disguise their silhouette just as animals use their big yellow eyes.
More important, they use these bioluminescent lights as a means to communicate or attract mates.