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 Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>