Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Zebrafish use sunscreen also for camouflage

Zebrafish embryos camouflage themselves against predators by adapting to the surface.

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:

Bettina Jakob | Universität Zürich
Further information:

More articles from Life Sciences:

nachricht ‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie

nachricht Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>