Thursday, January 22, 2015

The Shrimp that Can See Where UV Been.

Written by Kara Jew



What fearsome creatures come to mind when you think of ocean dwellers? There are a ton of creatures like the great white shark, box jellyfish, blue-ringed octopus, or stingray that would make you think twice about stepping foot in the ocean. However, there’s one particular marine organism that may evade your thoughts; one that keeps me awake at night: Odontodactylus scyllarus, or more commonly known as the Peacock Mantis Shrimp.























You may take a look at the mantis shrimp and laugh, because you might think that there’s no way that this shrimp could be menacing. It looks like a cartoon character with its psychedelically colored carapace and oddly shaped eyeballs. But as the saying goes, “don’t judge a book by its cover”. This mantis shrimp can pack a violent punch that can break through glass. When the mantis shrimp produces a punch a cavitation bubble forms aids in the destruction of the target. The formation does not cause the damage, but rather the collapse of the bubble. As the bubble pops tiny bolts of extremely violent energy are released in the form of heat, light, and sound can be produced. Fun fact: the temperature released from a cavitation bubble can reach up to 15,000 K!




More on cavitation bubbles with Hank Green from SciShow. 


Mantis Shrimp club doing what it was designed to do. The action begins at 1:00.




What is more remarkable about the mantis shrimp than its ability to knock you out is its ability to see things you can’t. Humans have been cursed with trichromatic vision meaning that we cannot see wavelengths beyond the red-blue-green spectrum. Contrastingly, mantis shrimp have been known to possess dodeca-chromatic color space. Can you guess what that means? They have 20 receptor types, 12 of these photoreceptors are dedicated to detecting color. Does that mean these mantis shrimp have the capability to see 9 colors unimaginable to the human mind? Unfortunately, that doesn’t seem to be the case. When compared with the human eye the mantis shrimp eye works in an unconventional manner.









The mantis shrimp compound eye is segmented into three regions: the dorsal hemisphere, ventral hemisphere, and the mid-band. Within the mid-band are 6 distinct rows of ommatidia that have different functions; rows 1-4 are dedicated to color processing, and rows 5-6 are involved in the detection of circular or linear polarized light. In each ommatidum, light will pass through the cornea and crystalline cones. These cones converge light on to the tip of the rhabdom, a receptive structure formed by a group of 8 photoreceptive cells. It has recently been found that one of these photoreceptors, retinular cell 8 (R8), is sensitive to 5 discrete wavelengths in the UV range. (310, 320, 330, 340, and 380 nm).

Mantis shrimp eye

Section of a mantis shrimp eye.



So, the question is, how are these crustaceans capable of detecting UV wavelengths?  A study found that there are specific and distinct visual and filtering pigments within the eye of the mantis shrimp (Bok et al., 2014). The mid-band contained two UV visual pigments that expressed maximum absorption at 334 nm and 383 nm; however, the presence of these two pigments were not enough to explain the intricately tuned sensitivity of the photoreceptors to UV wavelengths. In an attempt to further investigate this phenomenon, they simply subjected the eye to fluorescence at a visible wavelength (375 nm) they observed something quite fascinating.

A: Mantis shrimp illuminated with white light  B: Mantis shrimp eye illuminated with 375 nm UV light  (dPR: dorsal periphery; MB:midband; vPR: ventral periphery)  C: Cross-section through the eye with 365 epi-illumination.  Note the distinct fluorescence emissions: blue, cyan, and green  (CC:crystalline cone)  D: Cross-section across the CC layer; MB rows 3-6 display blue, cyan, and green fluoresce
A: Mantis shrimp illuminated with white light
B: Mantis shrimp eye illuminated with 375 nm UV light
(dPR: dorsal periphery; MB:midband; vPR: ventral periphery)
C: Cross-section through the eye with 365 epi-illumination.
(R: retina; Co: cornea; CC:crystalline cone)
Note the distinct fluorescence emissions: blue, cyan, and green in MB rows 3-6
D: Cross-section across the CC layer
Note the distinct fluorescence emissions: blue, cyan, and green in MB rows 3-6 & red in MB 1-2
Bok et al., 2014 




As seen in the picture above, illumination of the eye resulted in a compelling fluorescence pattern that contained 3 distinct fluorophore emissions in the mid-band (as can be seen in B-D: blue, cyan, and green).  It must also be noted that these emission patterns overlapped the pseudopupil, a dark streak in the eye that indicates the direction that the mantis shrimp is looking, which suggest that these fluorescent pigments are covering the optical path of the ommatidia (as seen in A-B). Analysis of the crystalline cones indicated that there are 4 unmistakable UV-absorbing pigments: rows 1-2, 3, 4, and 5-6 contained pigments that could be absorb maximally at 334, 372, 375, and 308 nm, respectively. (as seen in D). These UV-absorbing pigments acted as filtering pigments for the two previously noted visual pigments that could absorb maximally at 340 and 383 nm.  These UV-absorbing pigments are believed to be mycosporine-like amino acids (MAAs) which are referred to as “nature’s sunscreen”. MAAs are not synthesized by eukaryotic organisms, but the mechanism by which the mantis shrimp obtains these molecules are relatively unknown. It has been suggested that mantis shrimp consume organisms that produce their own MAAs and modify the molecules into filter pigments.


                                                                                                  
 Ze Frank sums up the life of the mantis shrimp.






If you ever cross paths with these inanely, clown-colored shrimp just remember to pick on someone your own size, because mantis shrimp can definitely give you a “bone-splitting” sucker punch.




References:

Bok, M.J., M.L. Porter, A.R. Place, and T.W. Cronin. 2014. Biological sunscreens tune polychromatic ultraviolet vision in mantis shrimp. Current Biology 24:1636-1642.

Marshall, J. and K. Arikawa. 2014. Unconventional colour vision. Current Biology 24:1150-1154.

Thoen, H.H.,  M.J. How, T. Chiou, and J. Marshall. 2014. A different form of color vision in mantis shrimp. Science 343:411-413.



Images:

http://blogs.discovermagazine.com/d-brief/2014/01/23/mantis-shrimps-bizarre-eyesight-finally-figured-out/


http://thedancingrest.com/2014/09/17/the-peacock-mantis-shrimp/

https://student.societyforscience.org/article/shrimp-packs-punch 

http://thedancingrest.com/2014/09/17/the-peacock-mantis-shrimp/




8 comments:

  1. Honey badger has nothing on the mantis shrimp... nice post Kara!

    ReplyDelete
  2. I love mantis shrimp! His eyeballs look like little burgers

    ReplyDelete
  3. Healing from HIV-AIDS, i never though dr.camala who could ever get my HIV-AIDS cured with his healing spell, i have tried almost everything but i couldn't find any solution on my disease, despite all these happening to me, i always spend alot to buy a HIV drugs from hospital and taking some several medications but no relieve, until one day i was just browsing on the internet when i come across a great post of !Michelle! who truly said that she was been diagnose with HIV and was healed that very week through the help of these great powerful healing spell doctor, sometime i really wonder why people called him Papa camala, i never knew it was all because of the great and perfect work that he has been doing that is causing all this. so i quickly contacted him, and he ask me some few questions and he said a thing i will never forget that anyone who contacted him is ! always getting his or her healing in just 6 hours after doing all he ask you, so i was amazed all the time i heard that from him, so i did all things only to see that at the very day which he said i will be healed, all the strength that has left me before rush back and i becomes very strong and healthy, this disease almost kills my life all because of me, so i will to hospital to give the final test to the disease and the doctor said i am HIV negative, i am very amazed and happy about the healing dr.camala gave to me from the ancient part of Africa, you can email him now for your own healing too at: dr.camalahivadscure@yahoo.com or WhatsApp him +2349055637784 thank you sir for healing me from HIV, i am Doris Carter.

    ReplyDelete
  4. I was cured from my herpes Disease. after suffering since 4years ago. but when i contact doc onokun on the internet. he gave me a Natural cure that ended my suffering after using it for two weeks. i went to check myself on the hospital and i was tested negative. I can't more happier but to say thank you sir and i use this medium to say to everyone don't waste any time to contact this powerful herbal Dr,onokun On any Kind of Disease he is Ready to help you. You can reach him through his email: dronokunherbalcure@gmail.com

    ReplyDelete
  5. I Want To Appreciate Dr.OYAGU for his great deeds, I Was Diagnosed With type 2 Herpes Virus Last year,And i Was Looking For Solution To Be Cured Luckily I Saw Testimonies On How Dr.OYAGU Cure Herpes Virus I Decided To Contact Dr.OYAGU I Contacted Him He Prepared A Herbal Medicine Portion And Sent It To Me,I Started The Herbal Medicine For My Health.He Gave Me Step By Step Instructions On How To Apply It, When I Applied It As Instructed, I Was Cured Of This Deadly Herpes Within 2 weeks, I Am Now Herpes Negative.My Brother And Sister I No That There Are So Many People That Have The Same Herpes Virus Please contact Dr OYAGU To Help You Too,And Help Me To Thank Dr.OYAGU For Cure Me, I’m Cured By Dr. OYAGU Herbal Medicine,His Contact Email:oyaguherbalhome@gmail.com

    Or Cell Whatsapp Number +2348101755322 thank you

    ReplyDelete
  6. I'm 61 years old, I contracted hpv in 2011' I has be taking lot treatment for it and embarrassed some months ago the wart stated coming out seriously, I used lot recommendation because there was lot warts around my anus and was so . but today I'm totally happy I got the virus eliminated by using natural treatment from Dr Onokun herbal center after his treatment I got cured. all the warts went away' seriously believed Dr Onokun he have the cure for human papillomavirus because he has eliminated hpv been in my body since 2011, Dr Onokun make it possible for me. Here is Dr Onokun email: dronokunherbalcure@gmail.com or website: https:// Dronokunherbalcure.wordpress.com/ page at: https://www.facebook.com/naturaltreatme    

    ReplyDelete
  7. I has suffered for Human papillomavirus HPV) for 2years, I was given some tablets at the hospital but I refused to take it, They said I have to be on it for life so I don't want take a drugs everyday for life. No point in taking medicine everyday when u won't get cure from it and I was advice to seek for natural herbal cure, after some time I found dr onokun is the most trustful herbalist that have herbs to cure wicked symptom's,I emailed dr onokun, for 2weeks been his patient he cured my (HPV) with his herbal. I only used his natural herbs for two weeks it was 100% cure. I'm not (HPV) patient anymore. I'm happy about it i finally got cured out of this mess been in my body for 2years. I also recommend you if you're living with (HPV) or herpes symptoms i also want you to be free contact dr onokun with the email attach to my post. Dronokunherbalcure@gmail.com

    ReplyDelete
  8. This is another testimony on how Chief Dr Lucky cured my HIV disease. Do you need a cure for your HIV disease? Do you want to be cured from your cancer disease? Or you want to be free from any type of disease. Kindly visit his website https://chiefdrluckyherbaltherapy.wordpress.com/ . He just cured my HIV disease and I’m very grateful to him, he is the only herbalist that can cure you.  
    WhatsApp number : +2348132777335 
    Via Email : chiefdrlucky@gmail.com
    Thank you all for reading,
    God bless"

    ReplyDelete