Navigation Links
Mid-ocean creatures control light to avoid becoming snacks
Date:11/10/2011

DURHAM, NC -- If you're a snack-sized squid or octopus living in the ocean zone where the last bit of daylight gives way, having some control over your reflection could be a matter of life and death.

Most predators cruising 600 to 1,000 meters below the surface spot the silhouette of their prey against the light background above them. But others use searchlights mounted on their heads.

Being transparent and a little bit reflective is a good defense against the silhouette-spotters, but it would be deadly against the "headlight fish," says Duke postdoctoral researcher Sarah Zylinski.

Transparency is the default state of both Japetella heathi, a bulbous, short-armed, 3-inch octopus, and Onychoteuthis banksii, a 5-inch squid found at these depths. Viewed from below against the light background, these animals are as invisible as they can be. Their eyes and guts, which are impossible to make clear, are instead reflective. But when hit with a flash of bluish light like that produced by headlight fish, they turn on skin pigments, called chromatophores, to become red in the blink of an eye.

During ship-board experiments over the Peru-Chile trench in 2010, Zylinski shined blue-filtered LED light on specimens of both creatures to watch them rapidly go from clear to opaque. When the light was removed, they immediately reverted to transparent. On a second research cruise in 2011 in the Sea of Cortez, Zylinski measured the reflectivity of the octopuses and found they reflected twice as much light in their transparent state as in the opaque state.

Zylinski experimented with 15 to 20 different species of cephalopod pulled up from the deep by the research ships, but only these two responded to the blue light. "I went through several things I thought would stimulate behaviors," she says. Shallow-water cephalopods (squid, ocotopi and cuttlefish) will change their body patterns for a shadow or shape passing overhead, but these deeper water animals don't, Zylinski says. The animals could be seen tracking the movements of probes around them, but it was only the light that made them switch on the their pigments.

Zylinski next would like to investigate the link between transparency and habitat depth for the Japetella octopus. "Smaller young animals are found higher in the water column and have fewer chromatophores, so they are more reliant on transparency, which makes sense because there won't be predators using searchlights there," Zylinski says. But the mature adults have a higher density of chromatophores making them potentially more opaque and they can be found in deeper waters (below 800 meters) where bioluminescence becomes the dominant light source.


'/>"/>

Contact: Karl Leif Bates
karl.bates@duke.edu
919-681-8054
Duke University
Source:Eurekalert  

Related biology news :

1. Researchers discover source of essential nutrients for mid-ocean algae
2. Snakes, salamanders and other creatures thrive in areas with higher deer populations
3. Sea creatures sex protein provides new insight into diabetes
4. Marine scientists return with rare creatures from the deep
5. Coastal creatures may have reduced ability to fight off infections in acidified oceans
6. Peacekeeping creatures help maintain woodland diversity
7. Run-off, emissions deliver double whammy to coastal marine creatures, UGA study finds
8. Hidden infections crucial to understanding, controlling disease outbreaks
9. bioMETRX, Inc. Signs Deal To Acquire Controlling Interest in Biometric Solutions, LLC
10. Can genetic information be controlled by light?
11. Genes that control cell death fingered in age-related hearing loss
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Mid-ocean creatures control light to avoid becoming snacks
(Date:3/23/2016)... 23, 2016 ... Gesichts- und Stimmerkennung mit Passwörtern     ... MESG ), ein führender Anbieter digitaler ... mit SpeechPro zusammenarbeitet, um erstmals dessen Biometrietechnologie ... die Möglichkeit angeboten, im Rahmen mobiler Apps ...
(Date:3/18/2016)... 18, 2016 --> ... ICT, Manned & Unmanned Vehicles, Physical infrastructure and Perimeter Surveillance ... in the border security market and the continuing migration crisis ... Europe has led visiongain to publish this ... --> defence & security companies in the ...
(Date:3/14/2016)... 14, 2016 NXTD ) ("NXT-ID" or ... market, announces the airing of a new series of commercials ... of March 21 st .  The commercials will air on ... Squawk on the Street show. --> NXTD ) ... mobile commerce market, announces the airing of a new series ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... April 29, 2016 Elekta is ... update to its industry-leading treatment planning software, is available ... Monaco version 5.11 provides significant performance ... calculation speeds up to four times faster than in ... the industry,s gold standard Monte Carlo ...
(Date:4/28/2016)... ... April 28, 2016 , ... Next week on May ... its first-in-class technologies for tissue stem cell counting and expansion to gene-editing scientists ... Reprogramming & CRISPR-based Genome Engineering in Burlington, Massachusetts. , The attention of most ...
(Date:4/27/2016)... ... April 27, 2016 , ... Shimadzu ... at the Spring 2016 Marijuana Business Conference and Expo. Shimadzu’s high-performance instruments enable ... metals, and more. Expo attendees can stop by booth 1021 to learn how ...
(Date:4/27/2016)... SILVER SPRING, Md. and RESEARCH ... -- United Therapeutics Corporation (NASDAQ: UTHR ) announced ... Co-Chief Executive Officer, of United Therapeutics will provide an ... Deutsche Bank 41 st Annual Health Care Conference. ... May 5, 2016, at 10:00 a.m. Eastern Time, and ...
Breaking Biology Technology: