Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stealth camouflage at night

13.03.2007
MBL study confirms cephalopods use rapid adaptive camouflage at night

Cuttlefish are well-known masters of disguise who use highly developed camouflage tactics to blend in almost instantaneously with their surroundings. These relatives of octopuses and squid are part of a class of animals called cephalopods and are found in marine habitats worldwide. Cephalopods use camouflage to change their appearance with a speed and diversity unparalleled in the animal kingdom, however there is no documentation to date that they use their diverse camouflage repertoire at night.

In a paper published in the April 2007 issue of The American Naturalist, MBL (Marine Biological Laboratory) Senior Scientist Roger Hanlon and his colleagues report, for the first time, that giant Australian cuttlefish employ night camouflage to adapt quickly to a variety of microhabitats on temperate rock reefs. The research sheds light on the animal's remarkable visual system and nighttime predator/prey interactions.

While it's known that some marine fish and invertebrates use night camouflage as an anti-predator tactic, most camouflage studies are based on observations taken during daytime or dusk because videotaping behavioral data at night can be technically difficult. According to Hanlon, many animals perform some type of nocturnal color change, but the biological explanations behind the phenomenon have received scant attention in the science world. "The scarcity of studies on visual predator/prey interactions at night constitutes a major gap in sensory and behavioral ecology," he says.

Using a Remotely Operated Vehicle (ROV) equipped with a video camera, Hanlon and his team observed the giant Australian cuttlefish, Sepia apama, on their southern Australian spawning grounds over the course of a week. They observed that only 3% of cuttlefish were camouflaged during the day, during peak spawning periods. However, at dusk, the animals settled to the bottom and 86% of them quickly adapted their body patterns to blend in with habitats from sea grass to rocky reefs.

"The fact that we observed multiple camouflage pattern types, each effective in different microhabitats, provides two important insights into visual predator/prey interactions at night," says Hanlon. "First, it provides the first behavioral evidence that cuttlefish have fine-tuned night vision. We know that in daytime they use visual information of their immediate surrounds to choose their camouflage pattern, and these new data demonstrate that they can fine-tune their camouflage patterns in concert with different visuals surrounds of each microhabitat at night. Curiously, the visual mechanism for night vision is largely unknown for cephalopods. Second, such fine-tuned camouflaged patterning implies strongly that fish predator vision at night is keen as well."

Visual predation at night is an unstudied phenomenon in the marine world, notes Hanlon. "From the perspective of a behavioral ecologist, we are ignorant of perhaps half of what goes on each daily cycle. There is a large ocean frontier out there yet to be studied."

Gina Hebert | EurekAlert!
Further information:
http://www.MBL.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>