Mollusks watch with eyes of rock
A lined chiton near Whidbey Island, Washington, was photographed about 50 feet below the surface.
April 15th, 2011
08:30 AM ET

Mollusks watch with eyes of rock

In the past month, we've seen eagle rays and mako sharks jumping aboard boats. Now it turns out mollusks may be watching us ... with eyes made of rock.

Daniel Speiser, a researcher at the University of California, Santa Barbara, collected chitons, 3-inch-long mollusks, from the Florida Keys and gave them vision tests during his graduate studies at Duke University in North Carolina.

Scientists had long known that chitons had primitive eyes, but it was thought they could only detect changes in light.

"Turns out they can see objects, though probably not well," Speiser said in a news release from the Santa Barbara school.

"Not well" means their vision is about 1,000 times weaker than that of humans, said Sönke Johnsen, associate professor of biology at Duke, who cooperated with Speiser in the research.

Still, that vision may be something to marvel at because chitons' eyes have lenses made of aragonite, a type of rock. According to the researchers, the chiton is the first creature found to have eyes not made of calcite.

Making lenses of aragonite may have been easy for the mollusks as their shells are made of the same material. And Speiser says the chitons likely evolved with eyes so they can spot predators.

While the chitons don't  have 20/20 vision, they do have a lot of eyes. Hundreds of the lenses cover their eight-sectioned shells, with light-sensitive clusters under each lens.

The study is published in Current Biology.

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Filed under: Animals • Nature
soundoff (80 Responses)
  1. BEZZY

    That's nasty...

    April 15, 2011 at 12:49 pm | Report abuse |
  2. YesWeDoCare

    @Jason – What the heck does this post have to do with Politics? 😉

    My bad. I just mentioned God, and again, tongue in cheek. However; having said that, bringing God into a subject about animals, mollusks etc. is maybe not totally on topic but it does kind of relate. We, humans and "creatures" are not here because a mathematician says so. But yeah, let's leave God out of it.

    And totally agree, again my bad, the Bible doesn't play into this thread or discussion at all. Sorry for going in that direction. Was just using a "book" to help illustrate my point about a "God". But apparently, shouldn't have gone to either one.

    Ok, I'm back on board. It's a friggin' mollusk and as JT rightfully said "it's a very pretty photograph".

    April 15, 2011 at 12:53 pm | Report abuse |
  3. Hugh

    To the author: many primitive eyes are made from calcite, but these are certainly not the only animals that don't have calcite. our eyes are made from proteins, not calcite. it may be the first creature with eyes made from carbonates that are not calcite, but that is different.

    April 15, 2011 at 1:32 pm | Report abuse |
  4. Dim Mak

    Man (Which according to atheists are just advanced chimps) are close to being able to create black holes in a lab as well as fusion (power of the sun). It's not far fetched to think a creator made everything. I disagree with organized religion's assessment on lots of things, but my brain tells me that it's possible for our existence to be planned out. The idea that God is some dummy floating on a cloud is kind of narrow minded and insulting. God is knowledge. I respectfully disagree with your magical "poof out of nothing" theory.

    April 15, 2011 at 1:48 pm | Report abuse |
  5. YesWeDoCare

    @Dim Mak,

    I'm confused. Not sure if your comment was directed to me or not. And if it was, I would politely ask that you address it to me using my s/n. Again, I'm confused. I thought we were on the same wavelength, maybe not?

    Anyways, I read my comments again. If you are commenting that I was saying "proof out of nothing", I don't really think I was. The point I was trying to make is that to comprehend the universe is next to impossible – "At Least To Me". That's the key wording – "At Least To Me". I don't think a set of mathematical equations can do justice to something as complex as the universe. Is that "proof out of nothing"?

    I'm a ex-electrical engineer. My whole career was spent on math, equations and proving theories. I was trained to think analytically and that everything is quantifiable. But, for ME, all of that analytical, logical thinking goes out the door when it comes to the universe and the planet we live on. There has to be a Creator. But does that mean we are supposed to figure out how the Creator created by using mathematical equations?

    Perhaps, as I am saying above, the problem is ME. I am a trained electrical engineer not a physicist or scientist. I know zero about black holes or fusion. So, clearly there are other's that are far, far more intelligent than me. Therefore, I must admit, what I think probably has no merit. Especially, if it is deemed by smarter people than me, as "proof out of nothing".

    And if your comment wasn't addressed to me then man, I'm really, really, confused.

    April 15, 2011 at 3:43 pm | Report abuse |
  6. Dim Mak

    @YesWeDoCare: I wasn't addressing you it was a general statement.

    April 15, 2011 at 3:51 pm | Report abuse |
  7. jason van atta

    Absolutely amazing. changes my perception of mollusks in every form...changes my perception of the possibilities for many other primitive critters and how they may perceive the world... I actually always just picked these guys off with my knife and never knew they could see me coming! far out..........

    April 15, 2011 at 6:06 pm | Report abuse |
  8. Timmay!


    April 15, 2011 at 8:58 pm | Report abuse |
  9. Neil

    lol @Bible Clown. Sharia Mollusk Law being enforced in Republican bathtubs – ha ha!

    April 16, 2011 at 12:22 am | Report abuse |
  10. swoopy009

    why have eyes to see a predator coming if you cant move to escape it?

    April 16, 2011 at 2:32 am | Report abuse |
    • Anon

      They can clamp down on the rock when they see a predator.

      April 17, 2011 at 1:44 pm | Report abuse |
  11. skrilla Gorilla

    I'm gay

    April 16, 2011 at 7:52 am | Report abuse |
  12. Kor

    God sparked the big bang and started evolution once the earth was ready for life to begin some 4 billion years ago. The earth being only 10k years old is a stupid crock

    April 16, 2011 at 7:32 pm | Report abuse |
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