Navigation Links
Giant squids' giant eyes: The better to see hungry whales with

It's no surprise that giant and colossal squid are big, but it's their eyes that are the real standouts when it comes to size, with diameters measuring two or three times that of any other animal. Now, researchers reporting online on March 15 in Current Biology, a Cell Press publication, have used complex computations to explain those massive peepers. Giant squids' 10-inch eyes allow them to see very large and hungry sperm whales from a distance in the pitch darkness of their deep-sea home.

According to the researchers' calculations, animals living underwater would have no use for such large eyes if the goal were to see an average object, such as prey smaller than themselves. That's why even the eyes of large whales aren't much more than 3.5 inches across.

"For seeing in dim light, a large eye is better than a small eye, simply because it picks up more light," said Dan-Eric Nilsson of Lund University. "But for animals that live in the sea or in lakes, the optical properties of water will severely restrict how far away things can be seen.

"Through complex computations we have found that for animals living in water, it does not pay to make eyes much bigger than an orange. Making eyes larger than that will only marginally improve vision, but eyes are expensive to build and maintain."

For Nilsson's team, that begged the question of why giant squid bother with their giant eyes. Using a mathematical model of underwater vision, they tested the benefits of very large eyes for a broad range of tasks under various light conditions. Those efforts showed that very large eyes aren't much better than smaller ones unless one wants to see something that is itself very big, like a whale.

Giant squid may also be unique in that they are powerful enough to escape a sperm whale once they've spotted one, Nilsson says. But how can giant squid see a sperm whale at depths beyond daylight's reach?

"The answer is bioluminescencelight produced by small gelatinous animals when they are disturbed by the whale moving through the water," Nilsson says. "It is well known that bioluminescence can reveal submarines at night, and diving sperm whales will become visible for the same reason."

The findings may also explain the large eyes of prehistoric ichthyosaurs, giant marine reptiles that looked something like dolphins, the researchers say. Although ichthyosaurs lived long before whales came along, they would have had to contend with giant predatory pliosaurs.

The new model can also be used to predict how far other animals can see underwater. "It is a powerful tool for understanding vision," Nilsson says.

Contact: Elisabeth (Lisa) Lyons
Cell Press

Related biology news :

1. 1,000 tags reveal mysteries of giant bluefin tuna
2. Conservation International gets support from Dreamworks Animation to protect giant pandas
3. Discovery of giant roaming deep sea protist provides new perspective on animal evolution
4. Doubling a gene in corn results in giant biomass
5. Tall tale of giant stingray circles the globe
6. Doubling a gene in corn results in giant biomass
7. Scientists rebuild giant moa using ancient DNA
8. Report documents the risks of giant invasive snakes in the US
9. Canopy giants and miniature fungi among 250 new species discovered in Kews 250th anniversary year
10. Microorganism may provide key to combating giant salvinia throughout Louisiana
11. Giant panda genome reveals new insights into the bears bamboo diet
Post Your Comments:
Related Image:
Giant squids' giant eyes: The better to see hungry whales with
(Date:3/31/2016)... , March 31, 2016  Genomics firm Nabsys has ... CEO, Barrett Bready , M.D., who returned to ... the original technical leadership team, including Chief Technology Officer, ... Product Development, Steve Nurnberg and Vice President of Software ... the company. Dr. Bready served as CEO ...
(Date:3/23/2016)... , March 23, 2016 ... Interesse erhöhter Sicherheit Gesichts- und Stimmerkennung mit ... Inc. (NASDAQ: MESG ), ein ... dass das Unternehmen mit SpeechPro zusammenarbeitet, um ... der Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, im ...
(Date:3/22/2016)... , PROVO and ... Newborn Screening Ontario (NSO), which operates the highest sample ... molecular testing, and Tute Genomics and UNIConnect, leaders in ... respectively, today announced the launch of a project to ... (NGS) testing panel. NSO has been ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Ky. , June 23, 2016 ... two Phase 1 clinical trials of its complement ... placebo-controlled, single and multiple ascending dose studies designed ... pharmacodynamics (PD) of subcutaneous injection in healthy adult ... subcutaneously (SC) either as a single dose (ranging ...
(Date:6/23/2016)... 23, 2016 On Wednesday, June 22, ... down 0.22%; the Dow Jones Industrial Average edged 0.27% lower ... 2,085.45, down 0.17%. has initiated coverage on the following ... Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals Inc. (NASDAQ: ... BIND ). Learn more about these stocks by accessing ...
(Date:6/23/2016)... ... June 23, 2016 , ... Velocity Products, a division of ... and optimized exclusively for Okuma CNC machining centers at The International Manufacturing Technology ... among several companies with expertise in toolholding, cutting tools, machining dynamics and distribution, ...
(Date:6/22/2016)... , June 22, 2016 Cell Applications, ... allow them to produce up to one billion ... lot within one week. These high-quality, consistent stem ... preparing cells and spend more time doing meaningful, ... a proprietary, high-volume manufacturing process that produces affordable, ...
Breaking Biology Technology: