Bizarre squid’s mismatched eyes help it survive in deep-sea, dark habitat
Bizarre deep-sea squid Histioteuthis heteropsis’ mismatched eyes help the marine creature survive in its cold and dark habitat, according to a new research.
Deep-sea dweller Histioteuthis heteropsis has been puzzling biologists since it was discovered more than a century ago because its bulging left eye is big and yellow, whereas its right eye is significantly smaller and clear.
In the 1970s, squid biologist Richard Young hypothesized that the squid’s larger eye detects dim sunlight, helping it in spotting prey swimming overhead. But, it proved to be very difficult to be studied because of its remote habitat, which can be as many as 3,300 feet deep.
Duke biologist Katie Thomas, who led the new study, said, “They are freaky and weird looking—you want to know what is going on with their eyeballs.”
Thomas and her colleagues watched three decades’ worth of video footage captured by remotely operated vehicles off the California coast. They found more than 150 instances in which the bizarre squid was captured on video and they used that information to measure the orientation of the creature’s body and eyes.
They found that the animal swims diagonally, with its bigger left eye constantly facing upward and the smaller right eye facing downward. With the help of computer simulations of visual sensitivity, they determined that the larger eye significantly enhances visual capability when detecting creatures illuminated by the dim sunlight coming from above.
The findings of the new study published in the journal Philosophical Transactions B on Monday, Feb. 13, 2017.