Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Leading lampreys to slaughter: Pheromone for scourge of Great Lakes identified

04.10.2005


For the rats of Hamelin, it was the Pied Piper’s tune. For the destructive sea lamprey of the Great Lakes, it’s a chemical attractant, or pheromone, released by lamprey larvae living in streambeds. Following the pheromone trail, adults are drawn to streams favorable for spawning. Researchers have long wanted to identify the pheromone so it could be synthesized and used to control the sea lamprey, which laid waste to Great Lakes fisheries of lake trout and other species in the mid-20th century. Now, a team of University of Minnesota researchers has identified the three major components of the pheromone and synthesized the principal one, a novel steroid akin to a shark steroid that possesses anticancer activity. This is the first migratory attractant to be identified in any fish. The work is the cover story for the November issue of Nature Chemical Biology and will be published online in the journal Sunday, Oct. 2.



The lamprey is one of the earliest relics of vertebrate evolution, dating back nearly 400 million years, before the evolution of jaws and bony skeletons. The species parasitizes other fish by attaching with their circular, toothy mouths and sucking the body juices. A single lamprey will feed for about a year, consuming on average 40 pounds of fish. In the Great Lakes, their prey have been commercially valuable species like lake trout and whitefish.

Currently, the Great Lakes Fishery Commission (GLFC) controls lamprey by means of a poison that kills lamprey larvae in streambeds. It also kills every invertebrate it comes in contact with, and sometimes fish. The lampricide is tanker-trucked to streams, some of them in populated areas, in an expensive, labor-intensive and unpopular undertaking. The GLFC is eager to use a synthetic form of the newly found pheromone to replace the poison by luring lamprey to traps and sterilizing the males, the researchers said. Using the pheromone would be environmentally friendly and less expensive.


"The GLFC has the goal of controlling lamprey with a new and better technique by 2010. This could be it," said Peter Sorensen, a professor of fisheries, wildlife and conservation biology who led the study with chemistry professor Thomas Hoye. "Also, lamprey are important to native peoples on the West Coast, who value it for food. This pheromone could help restore lamprey runs by attracting lamprey to suitable spawning beds."

When they stop feeding, lamprey seek out streams for spawning by following the pheromone trails. After arriving at the spawning grounds, a sex pheromone -- which was identified by Weiming Li, an earlier doctoral student of Sorensen -- attracts the females to males. After spawning, which takes a few weeks, the adults die.

It has taken Sorensen and his colleagues about 15 years to find, isolate and purify the pheromone so that Hoye and his colleagues could identify and synthesize it. The key component is a steroid with potency so great that lampreys would smell a single gram dissolved in 10 billion liters of water, enough to fill 5,000 Olympic-sized swimming pools. This level of potency tops that of all other fish attractants, including those of salmon.

To find the pheromone, the researchers extracted 8,000 liters of water from tanks holding 35,000 larvae. The yield was less than a milligram, or 35 millionths of an ounce. Much of the work in isolating and purifying the pheromone was performed by Sorensen’s graduate student Jared Fine, while Vadims Dvornikovs, Christopher Jeffrey and Feng Shao in Hoye’s lab were integral to synthesizing the key component, called PADS. The chemical structure of PADS is very similar to that of squalamine, a compound made by the "dogfish" shark. Squalamine has been reported to work against cancer by inhibiting the growth of blood vessels that feed tumors but not other blood vessels. The other two components of the pheromone are a second steroid and an already known, lamprey-specific bile acid derivative.

Until the pheromone can be synthesized in bulk, extracts of water from larval lamprey nurseries are being used to trap adults on an experimental basis in Michigan streams.

"Using these extracts has been shown to work," said Sorensen. "Capture rates are up six-fold." Most lamprey traps have been simple, rather ineffective devices, but now the attractants have opened up many new possibilities for attracting lampreys safely, easily and inexpensively into streams, where they might be captured. In theory, the cue could attract lampreys from many locations for miles around and could work for as long as several months.

The work was supported by GLFC, the University of Minnesota Agricultural Experiment Station and the National Institutes of Health.

Deane Morrison | EurekAlert!
Further information:
http://www.umn.edu

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>