Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Large caps this spring's must-have for water fleas

03.05.2010
It remains one of the unresolved mysteries of the animal world: why do females change the way they look each season while males look the same all year round?

Researchers at the University of Gothenburg, Sweden, who have been studying fashion trends for water fleas have found some of the answers.

What can millimetre-long water fleas from twenty small lakes in the Munkedal district of south-west Sweden have to say about animals' winter and summer fashions? A lot, as it happens. The water flea is, in fact, one of the world's trendiest crustaceans.

New accessories
Water fleas have the ability to change their appearance to suit their surroundings and the season. This may involve, for example, donning new accessories: water fleas can grow long antennae, a larger back hump or a new "cap" of varying sizes. Researchers at the Department of Zoology at the University of Gothenburg who studied water fleas in the Örekilsälven river basin believe these accessories to be the water fleas' way of reducing the risk of being caught and eaten.
Different trends
What's remarkable is that water fleas in different lakes follow different trends. For example, high up in the Örekilsälven water system, the females have been wearing small round caps teamed with fairly large bodies, while their counterparts further down in the system have gone the other way - larger caps but smaller bodies.
Fashion for protection
Hans Lord, researcher at the Department of Zoology, offers an explanation in his thesis. A large cap protects the water fleas from small invertebrate predators, as it makes it harder for these predators to catch and hang on to them. Smaller bodies, in turn, are the water fleas' way of adapting to predatory fish, which rely on their sight to locate their prey. The combination of a small body and a large cap is a compromise: the smaller body reduces the risk of being spotted by a fish, while the large cap (which is transparent and therefore invisible to the fish) offers protection from invertebrate predators.
Males not trendy
The males, on the other hand, don't seem at all bothered by current trends.
This may be to do with reproduction: given that the females carry the offspring, a dead female is a greater loss than a dead male. It is therefore more worthwhile for the females to invest in a look that will protect them against predators. Another explanation is that the males are driven by their need to find females to mate with as quickly as possible - and that swimming up to a female whilst wearing a large cap and long antennae requires too much energy, takes too long and entails a risk that other males will get there first.
Extravagant for summer
This also explains why the fashions are more extravagant in the summer than the winter. "When the water's cold, it's more difficult to move through, which makes it extra-hard to swim with accessories," says Lord, researcher at the Department of Zoology and expert in fashion trends for water fleas. "This is one of the explanations for why we find water fleas with extreme looks during the summer only, when the water is warm, but not during the rest of the year. Another explanation is that the summer brings more invertebrate predators."
The thesis Morphological antipredator adaptations in water fleas has
been defended at the Department of Zoology. Download the thesis from:
http://gupea.ub.gu.se/dspace/handle/2077/21030
Contact:
Hans Lord, Department of Zoology, University of Gothenburg
+46(0)31 174 940
hans.lord@zool.gu.se

Helena Aaberg | idw
Further information:
http://www.gu.se/
http://gupea.ub.gu.se/dspace/handle/2077/21030

Further reports about: Gothenburg Large Hadron Collider Zoology water fleas

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>