Neurobiologists from the University of Zurich have discovered that this camouflage mechanism actually started out as sunscreen to protect the fish against DNA damaging shortwave solar radiation at embryonic stages.
Zebrafish with different pigmentation and camouflage. The bottom animal is on a light subsurface. The top animal is blind, thus incapable of discerning the lightness of the subsurface and
Picture: Stephan Neuhauss / UZH
Camouflage among zebrafish larvae. The left-hand larva is exposed to bright light and has little pigmentation; the right-hand larva against a dark subsurface is more heavily pigmented.
Picture: Stephan Neuhauss / UZH
For diurnal animals like zebrafish embryos, which grow up in shallow pools and are practically see-through, exposure to the sun constitutes a major problem since ultraviolet (UV) radiation damages DNA.
Neurobiologists Stephan Neuhauss and Kaspar Müller from the Institute of Molecular Biology at the University of Zurich set about investigating which mechanisms zebrafish embryos use to protect themselves against the aggressive UV radiation. Interestingly, the two scientists reveal in their article recently published in the journal PLOS ONE, the UV-protection mechanism also doubles as camouflage.
Sunscreen already from day two
For their study, the scientists examined zebrafish embryos, the skin cells of which already possess pigments known as melanosomes from the second day after fertilization – even before their eyes have developed. “In strong solar radiation, the pigments spread along predetermined paths within the cells, after which the zebrafish embryo appears darker,” explains Neuhauss. As the researchers discovered, this distribution process of dark pigments in the presence of intense light always takes place, regardless of whether the embryo is on a light or dark subsurface. Surprisingly, the embryos display a noticeable change from the third day after fertilization: They adapt to the subsurface. According to Neuhauss, this is because the embryos can see from day three and have eyes with UV-sensitive photoreceptors in the retina. From this moment on, they are able to discern whether they are on a light or dark subsurface and can adapt and thus camouflage themselves accordingly. As long as the animal is in the embryonic stage and see-through, however, the benefits of UV protection prevail.When the skin is no longer transparent and does not require protection against aggressive radiation, the selective distribution of the pigments within the skin cells is predominantly used for camouflage purposes. And with good reason: Being able to adapt to a lighter or darker subsurface and camouflage yourself reduces the chance of being spotted and eaten. “The original UV protection turns into a camouflage mechanism – a striking example of the secondary use of an existing capability,” Neuhauss concludes.
Kaspar P. Müller, Stephan C. F. Neuhauss, Sunscreen for Fish: Co-option of UV light protection for camouflage. PLOS ONE. January 29, 2014. Link: http://dx.plos.org/10.1371/journal.pone.0087372
Bettina Jakob | Universität Zürich
The first genome of a coral reef fish
29.09.2016 | King Abdullah University of Science and Technology
New switch decides between genome repair and death of cells
27.09.2016 | University of Cologne - Universität zu Köln
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
28.09.2016 | Event News
27.09.2016 | Event News
23.09.2016 | Event News
29.09.2016 | Life Sciences
29.09.2016 | Medical Engineering
29.09.2016 | Physics and Astronomy