Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Finally, Male Water Fleas Exposed

08.12.2005


Male water fleas that scientists have never seen have made their debut in a University at Buffalo laboratory, providing biologists with their first glimpse of these elusive organisms.


This male water flea of Bosmina genus debuted in a UB lab.



The UB research, published last month in Proceedings of the Royal Society: Biological Sciences, opens a new window on the biological diversity of several species of water fleas, including those in the genus Daphnia and the genus Bosmina, that play major roles in freshwater food webs.

It also demonstrates that pesticides that mimic the hormone used in the UB experiments may have much broader effects than initially believed, and could damage populations of fish and other organisms higher up in the food chain.


"Most freshwater fish eat water fleas at some point in their lives," said Derek J. Taylor, Ph.D., associate professor of biological sciences in UB’s College of Arts and Sciences and co-author on the paper. "They are an important food source for fish."

Water fleas are nearly microscopic organisms with transparent bodies. Found in lakes, ponds and other bodies of fresh water, they are crustaceans like lobsters and not insects, as their name suggests.

"People use water fleas as aquatic ’coal-mine canaries,’" said Taylor. "They are good indicators of environmental change."

In stable environments, female water fleas generally reproduce asexually, essentially cloning themselves and resulting in populations of females that are practically impossible to tell apart.

Water flea populations grow much faster when they reproduce asexually than when they do so sexually, Taylor explained.

He added that the practice of rarely producing males has likely been conserved for 100 million years or more in a large group of freshwater crustaceans.

In the UB experiments, four distantly related species of water fleas were exposed to methyl farnesoate (MF), a crustacean juvenile hormone that is known to determine sex in some species that regularly produce males.

The researchers found that the MF exposure caused the production of males in different families of water fleas, despite the fact that they were only distantly related to each other and despite the fact that laboratory conditions were designed to be unfavorable to the production of males.

"Because the same MF hormone affects a broad range of crustaceans, any insecticide that mimics MF also may affect a large number of species in freshwater communities," said Taylor.

"In other words, MF-based insecticides are not insect-specific, and if you affect a non-target species that’s a major player in these freshwater food webs, then it will affect things higher up the food chain," he said.

The increased production of males after exposure to these insecticides could reduce water flea populations significantly, adversely affecting freshwater fish populations, he said.

The induction of males in the lab comes at an important time, Taylor explained, since the Daphnia genome is expected to be published next year. Taylor is a member of the consortium based at Indiana University that is working on the genome.

"Breeding studies with both males and females often are necessary to identify candidate genes responsible for certain genetic traits," Taylor said. "If we want to understand, for example, the genetic basis for why some clones of Daphnia from lakes are more resistant to pollution, then having males could help to find the genes in the genome."

Male water fleas, Taylor explained, are assigned more readily to a species than are females, but males are only rarely produced and for many species, have never been seen.

"We need to know the species identities in order to understand how freshwater communities are changing over time, as a response to climate change, pollution or invasive species," said Taylor. "We’re hoping that by studying the biology of the rare males, we can learn more about species diversity and freshwater ecosystem changes."

The male-inducing tool now will be used to understand water flea species diversity on a global scale.

Co-authors on the paper are Keonho Kim, doctoral candidate in the UB Department of Biological Sciences, and Alexey A. Kotov, Ph.D., scientist at the A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences in Moscow.

The research was supported by a grant from the National Science Foundation, "Partnership for Enhancing Expertise in Taxonomy."

The University at Buffalo is a premier research-intensive public university, the largest and most comprehensive campus in the State University of New York.

Ellen Goldbaum | EurekAlert!
Further information:
http://www.buffalo.edu

More articles from Life Sciences:

nachricht New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | 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: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

New drug reduces transplant and mortality rates significantly in patients with hepatitis C

29.05.2017 | Statistics

VideoLinks
B2B-VideoLinks
More VideoLinks >>>