Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Global warming changes balance between parasite and host in fish -- new study

05.12.2011
Worms infecting fish grow 4 times faster at higher temperatures and manipulate the behavior of fish

Parasitic worms that infect fish, and have a devastating effect on fish reproduction, grow four times faster at higher temperatures – providing some of the first evidence that global warming affects the interactions between parasites and their hosts.

The study from the University of Leicester revealed that global warming had the potential to change the balance between parasite and host - with potentially serious implications for fish populations.

The researchers from the University of Leicester's Department of Biology also observed behavioural change in infected fish – suggesting parasites may manipulate host behaviour to make them seek out warmer temperatures.

And they discovered that whilst parasites grew faster in higher temperatures, the host's growth rate slowed.

"What we witnessed was that fish infected with the largest worms showed a preference for warmer water, suggesting that these parasites also manipulate the behaviour of host fish in ways that benefit the parasites by maximizing their growth rates," said Dr Iain Barber of the Department of Biology at the University of Leicester, who carried out the study with doctoral student Vicki Macnab.

The research, supported by funding from the Biotechnology and Biological Sciences Research Council (BBSRC) and the Centre for Environment, Fisheries and Aquaculture Science (Cefas), has been published today in the influential journal Global Change Biology.

Vicki said: "The research shows a dramatic effect of increased environmental temperatures on the growth rates of parasites in fish hosts. The size these parasites attain in their fish hosts determines how severely fish reproduction is affected, so our results suggest that parasite will have a more serious effect on fish reproduction if temperatures rise. In addition, our paper documents behavioural changes in infected fish that suggests the parasites are manipulating host behaviour to make them seek out warmer temperatures, creating a positive feedback mechanism to exacerbate the effects of global warming.

"This research shows that global warming could shift the balance between parasites and their hosts with potentially serious implications for fish populations."

The scientists found that parasitic worms infecting stickleback fish grew four times faster in experimentally infected sticklebacks raised at 20°C than when raised at 15°C.

In contrast, the fish grew more slowly at the higher temperature, suggesting that fish parasites cope with higher temperatures much better than the fish they infect.

Dr Barber said: "The results are important because the size these parasites attain in their fish hosts also determines their infectivity to fish-eating birds like kingfishers and herons – the next hosts in the parasite's life cycle – and also the number of parasite eggs that they will go on to produce. Bigger larval parasites in the fish go on to become larger adult worms in birds, which produce more eggs.

"After the 8 weeks of the study, all of the worms infecting the fish held at 20C were ready to infect fish-eating birds, whereas none of those held at the lower temperature had reached a size at which they were ready to be transmitted."

In a follow up study, the authors also showed that fish infected with the largest worms showed a preference for warmer water, suggesting that these parasites also manipulate the behaviour of host fish in ways that benefit the parasites and maximize their growth rates.

The results provide some of the first evidence that increasing environmental temperatures can lead to a shift in the delicate balance that exists between co-evolved hosts and parasites, increasing the speed with which parasites complete their life cycles that could lead to an increase in the overall level of parasitism in natural animal populations.

For more information, please contact:

Dr Iain Barber
Head of Department
Department of Biology
College of Medicine, Biological Sciences and Psychology
University of Leicester
Tel: +44(0)116 252 3462
email: ib50@le.ac.uk
Reference: Macnab, V. & Barber, I. (2011) Some (worms) like it hot: fish parasites grow faster in warmer water, and alter host thermal preferences. Global Change Biology in press. DOI: 10.1111/j.1365-2486.2011.02595.x

http://doi.wiley.com/10.1111/j.1365-2486.2011.02595.x

Affiliations: Vicki Macnab is a PhD student funded by the BBSRC and Cefas; Dr. Iain Barber is senior lecturer and Head of the Department of Biology at the University of Leicester.

About the BBSRC

BBSRC invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.

Funded by Government, and with an annual budget of around £445M, we support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.

For more information about BBSRC, our science and our impact see: http://www.bbsrc.ac.uk

About Cefas

Cefas is an internationally renowned scientific research and advisory establishment. Operating as an executive agency of the Department for Environment, Food and Rural Affairs (Defra), it has been investigating marine and aquatic environments since 1902. It has two main laboratories, in Lowestoft and Weymouth, and works out of a number of port offices around the English coastline.

Cefas works alongside government and other agencies, both in the UK and internationally, to play a vital role in securing healthy marine and freshwater environments for everyone's well-being, health and prosperity. For more about its work and range of applied marine science, visit: www.cefas.defra.gov.uk

About the Journal

Global Change Biology exists to promote understanding of the interface between all aspects of current environmental change that affects a substantial part of the globe and biological systems. Studies must concern biological systems, regardless of whether they are aquatic or terrestrial, and managed or natural environments. Both biological responses and feedbacks to change are included, and may be considered at any level of organization from molecular to biome. Studies may employ theoretical, modeling, analytical, experimental, observational, and historical approaches and should be exploratory rather than confirmatory. GCB publishes primary research articles, technical advances, research reviews, commentaries and letters.

Journal URL: http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2486

Dr. Iain Barber | EurekAlert!
Further information:
http://www.le.ac.uk

More articles from Ecology, The Environment and Conservation:

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>