On the open sand plains of the Caribbean seafloor, where soft-bodied animals are routinely exposed to predators, camouflage can be key to survival. Perhaps no group of animals is quite as adept at blending in with its surroundings as cephalopods, who along with relatives the cuttlefish and squid, have evolved a unique skin system that can instantaneously change their appearance.
In the February 2010 issue of The Biological Bulletin, MBL Senior Scientist and cephalopod expert Roger Hanlon and his colleagues report the exceptional camouflage capabilities of the Atlantic longarm octopus, Macrotritopus defilippi, whose strategy for avoiding predators includes expertly disguising itself as a flounder. While Hanlon and others have documented two other species of octopuses imitating flounder in Indonesian waters, this is the first report of flounder mimicry by an Atlantic octopus, and only the fourth convincing case of mimicry for cephalopods.
Comparing still photographs and video footage from five Caribbean locations collected over the last decade, Hanlon and co-authors, MBL graduate students Anya Watson and Alexandra Barbosa, observed uncanny similarities between the small and delicate octopus and the peacock flounder, Bothus lunatus, one of the most common sand dwellers in the Caribbean. They compared not only coloration, which in each animal resembled the sandy seafloor, but swimming speed and form.
Just like flounder, the octopuses contoured their bodies to hug the wavy seafloor, tapering their arms behind them. They also swam with the same fits and starts as flounder at the same speeds. Interestingly, the octopuses mimicked flounder only when swimming, when movement would compromise their camouflage. How well the animals blended in with their background differed. The octopus showed more highly controlled and rapid skin patterning than the flounder, whose camouflage was slower and less precise.
“We were equally impressed with the remarkable camouflage of this small octopus species even when it was stationary yet entirely exposed on top of the open sand,” says Hanlon. “The apparent match in pattern, color, brightness, and even 3-dimensional skin texture was noteworthy even when compared to other changeable cephalopods. They also demonstrated an unusual form of disruptive camouflage.”
So why do Atlantic longarm octopuses choose to imitate flounder as a way to avoid the threat of predators? More study of cephalopod mimicry is needed, but a possible explanation, according to Hanlon and his team, could be that predators who could easily take a bite out of the small, soft octopus might find a rigid flatfish like the flounder too much of a mouthful and avoid them.
This research was supported by grants from the Sholley Foundation, Office of Naval Research, Our World-Underwater Scholarship Society, and Fundacao para a Ciencia e a Tecnologia, Portugal.
For a copy of the paper, please contact Carol Schachinger at firstname.lastname@example.org.
Published since 1897 by the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, The Biological Bulletin is one of America's oldest, peer-reviewed scientific journals. It publishes outstanding experimental research on the full range of biological topics and organisms, from the fields of Neuroscience, Behavior, Physiology, Ecology, Evolution, Development, Reproduction, Cell Biology, Biomechanics, Symbiosis, and Systematics; and it especially invites articles about those novel phenomena and contexts characteristic of intersecting fields. The electronic version, Biological Bulletin Online, contains the full content of each issue, including all figures and tables, beginning with the February 2001 issue. PDF files of the entire archive from 1897-2000 are also available.
The MBL is a leading international, independent, nonprofit institution dedicated to discovery and to improving the human condition through creative research and education in the biological, biomedical and environmental sciences. Founded in 1888 as the Marine Biological Laboratory, the MBL is the oldest private marine laboratory in the Americas. For more information, visit www.MBL.edu.
Gina Hebert | EurekAlert!
Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology
Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
23.11.2017 | Information Technology
23.11.2017 | Physics and Astronomy
23.11.2017 | Life Sciences