• ArtsandLectures twitter avatar
    We hope you can join us as we elevate our spirits with joyful gospel music and holiday classics in a roof-raising m… https://t.co/AQYVHMJA7X
    15 hours 51 min ago
  • UCSBgauchos twitter avatar
    Winners of Seven Straight Games, 8-2 UCSB Travels to USC Sunday https://t.co/f3If3ejwYk
    16 hours 53 min ago
  • UCSBgauchos twitter avatar
    Winners of Six Straight Games, 8-2 UCSB Travels to USC Sunday https://t.co/f3If3ejwYk
    17 hours 11 min ago
  • UCSBLibrary twitter avatar
    ICYMI. Our friends at UCLA have invited Gauchos to their late night study this finals week at @UCLA_Powell and… https://t.co/7SvvhUJzFa
    18 hours 5 min ago
  • UCSB_GradPost twitter avatar
    National Institute of Justice's Research Assistantship Program https://t.co/BaaQUhAad7 #UCSB #ucsbgradpost
    18 hours 9 min ago
  • ucsantabarbara twitter avatar
    More recognition for #UCSB faculty members. Three professors have been named fellows of the Institute of Electrical… https://t.co/7l3QI51qtl
    18 hours 29 min ago
  • UCSB_GradPost twitter avatar
    Applications open for Litfin Performing Arts Scholarship https://t.co/xZyxvpIZbC #UCSB #ucsbgradpost
    18 hours 44 min ago
  • UCSB_GradPost twitter avatar
    Apply now for L’Oréal's Women in Science program https://t.co/pjkjML2eSh #UCSB #ucsbgradpost
    19 hours 20 min ago
  • UCSB_GradPost twitter avatar
    Postdoc opportunity at UCSF Center for Health and Community https://t.co/Ab49ZFuOLw #UCSB #ucsbgradpost
    19 hours 56 min ago
  • UCSB_GradPost twitter avatar
    UCHRI offers new grant to support digital humanities projects https://t.co/wtR3VTQRgA #UCSB #ucsbgradpost
    19 hours 57 min ago
  • UCSBgauchos twitter avatar
    Gauchos Travel to No. 17 Oregon State Saturday; Host LMU Monday Afternoon https://t.co/N37Uleh56p
    20 hours 19 min ago
  • UCSB_GradPost twitter avatar
    Resources and updates on the Thomas fire https://t.co/ZkdITGqNhu #UCSB #ucsbgradpost
    21 hours 2 min ago
  • brenucsb twitter avatar
    .@UniOfYork scientists used sea water and scrap metal to develop a technology that could help capture more than 850… https://t.co/EHNrbCwa6K
    21 hours 42 min ago

Seeing Without Eyes

A new study demonstrates that an octopus’s skin possesses the same cellular mechanism for detecting light as its eyes do
Wednesday, May 20, 2015 - 15:00
Santa Barbara, CA
Octopus skin can sense light even without input from the eyes or brain.

OctopusHiRescropped.jpg

Octopus hatchling

A California two-spot octopus hatchling.

Figure 1.jpg

Chromatophores in their contracted state (left) and at maximum expansion (right).

 

Todd Oakley and Desmond Ramirez.jpg

Oakley and Ramirez

Todd Oakley, left, and Desmond Ramirez

Photo Credit: 

Sonia Fernandez

The octopus has a unique ability. It can change the color, pattern and even texture of its skin not only for purposes of camouflage but also as a means of communication. The most intelligent, most mobile and largest of all mollusks, these cephalopods use their almost humanlike eyes to send signals to pigmented organs in their skin called chromatophores, which expand and contract to alter their appearance.

A new study by UCSB scientists has found that the skin of the California two-spot octopus (Octopus bimaculoides) can sense light even without input from the central nervous system. The animal does so by using the same family of light-sensitive proteins called opsins found in its eyes — a process not previously described for cephalopods. The researchers’ findings appear in the Journal of Experimental Biology.

“Octopus skin doesn’t sense light in the same amount of detail as the animal does when it uses its eyes and brain,” said lead author Desmond Ramirez, a doctoral student in the Department of Ecology, Evolution and Marine Biology (EEMB). “But it can sense an increase or change in light. Its skin is not detecting contrast and edge but rather brightness.”

As part of the experiment, Ramirez shone white light on the tissue, which caused the chromatophores to expand and change color. When the light was turned off, the chromatophores relaxed and the skin returned to its original hue. This process, Ramirez noted, suggests that light sensors are connected to the chromatophores and that this enables a response without input from the brain or eyes. He and his co-author, Todd Oakley, an EEMB professor, dubbed the process Light-Activated Chromatophore Expansion (LACE).

In order to record the skin’s sensitivity across the spectrum, Ramirez exposed octopus skin to different wavelengths of light from violet to orange and found that chromatophore response time was quickest under blue light. Molecular experiments to determine which proteins were expressed in the skin followed. Ramirez found rhodopsin — usually produced in the eye — in the sensory neurons on the tissue’s surface.

According to Oakley, this new research suggests an evolutionary adaptation. “We’ve discovered new components of this really complex behavior of octopus camouflage,” said Oakley, who calls cephalopods the rock stars of the invertebrate world.

“It looks like the existing cellular mechanism for light detection in octopus eyes, which has been around for quite some time, has been co-opted for light sensing in the animal’s skin and used for LACE,” he explained. “So instead of completely inventing new things, LACE puts parts together in new ways and combinations.”

Octopuses are not the only marine mollusks whose skin can sense light, but scientists don’t know yet whether the skin of those other animals contains the light-sensitive opsins. If they do, Ramirez wants to understand how these two groups are related.“Do they all come from the same ancestral source or did they evolve multiple times?” he asked. “What kind of behaviors do the different groups share and what kind of behaviors does the skin sensing light underlie?”

Ramirez and Oakley are conducting new experiments that will seek to answer those questions and more.

Contact Info: 

Julie Cohen
julie.cohen@ucsb.edu
(805) 893-7220

Topics: