Featured Research

from universities, journals, and other organizations

Finally, Male Water Fleas Exposed

Date:
December 7, 2005
Source:
University at Buffalo
Summary:
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. The 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.

This male water flea of Bosmina genus debuted in a UB lab.
Credit: Image courtesy of University at Buffalo

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.

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.


Story Source:

The above story is based on materials provided by University at Buffalo. Note: Materials may be edited for content and length.


Cite This Page:

University at Buffalo. "Finally, Male Water Fleas Exposed." ScienceDaily. ScienceDaily, 7 December 2005. <www.sciencedaily.com/releases/2005/12/051206162424.htm>.
University at Buffalo. (2005, December 7). Finally, Male Water Fleas Exposed. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2005/12/051206162424.htm
University at Buffalo. "Finally, Male Water Fleas Exposed." ScienceDaily. www.sciencedaily.com/releases/2005/12/051206162424.htm (accessed September 20, 2014).

Share This



More Plants & Animals News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins