Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Killer Catfish? Venomous Species Surprisingly Common

14.12.2009
Name all the venomous animals you can think of and you probably come up with snakes, spiders, bees, wasps and perhaps poisonous frogs. But catfish?

A new study by University of Michigan graduate student Jeremy Wright finds that at least 1,250 and possibly more than 1,600 species of catfish may be venomous---far more than previously believed. The research is described in a paper published online Dec. 4 in the open access journal BMC Evolutionary Biology.

Lest anyone have concerns about attacks of killer catfish, rest assured that, at least in North America, these finned fatales use their venom mainly to defend themselves against predatory fish, though they can inflict a painful sting that many fishermen have suffered. In other parts of the world, some catfish do have extremely toxic venoms that can be deadly to humans.

Scientists have focused a great deal of attention of venom produced by snakes and spiders, but venomous fish had been largely neglected, said Wright, who used histological and toxicological techniques, as well as previous studies of evolutionary relationships among catfish species, to catalog the presence of venom glands and investigate their biological effects.

Catfish venom glands are found alongside sharp, bony spines on the edges of the dorsal and pectoral fins, and these spines can be locked into place when the catfish is threatened. When a spine jabs a potential predator, the membrane surrounding the venom gland cells is torn, releasing venom into the wound. In his paper, Wright describes how catfish venoms poison nerves and break down red blood cells, producing such effects as severe pain, reduced blood flow, muscle spasms and respiratory distress. However, because none of the species he examined produces more than three distinct toxins in its venom, each species probably displays only a subset of the whole repertoire of effects.

The main dangers to humans who tangle with North American catfish come not from the initial sting and inflammation, but from secondary bacterial and fungal infections that can be introduced through the puncture wound or when pieces of the spine and other tissue break off in the wound, Wright said. "In such cases, complications associated with these infections and foreign bodies can last several months."

On the evolutionary side, Wright's analyses point to at least two independent origins of catfish venom glands. In addition, the toxic proteins show strong similarities with, and might be derived from, previously characterized toxins found in catfish skin secretions.

Those toxins in catfish skin secretions have been shown to accelerate wound healing in humans, so it's possible that the proteins from their venom glands could have similar properties. Probably not very likely, given the known effects of these venoms on humans, but perhaps worth investigating, Wright said.

"I'm currently working to isolate particular toxins and determine their chemical structures and the genes responsible for their production," he said. "It's a very poorly-studied area, with little in the way of scientific literature to draw on, and my studies are just getting off the ground. So at this point it remains to be seen whether they'll have any therapeutic value, though it's worth pointing out that toxins from the venoms of other organisms---snakes, cone snails and scorpions, for example---have all been put to pharmaceutical and therapeutic use."

Further examination of the chemical composition of the venoms also will provide valuable insight into the mechanisms and potential selective factors driving venom evolution in fishes, Wright said.

Wright received financial support from the U-M Museum of Zoology and the U-M Rackham Graduate School.

More information:
Jeremy Wright: http://www.eeb.lsa.umich.edu/eeb/people/grads/jjwright.html
BMC Evolutionary Biology: http://www.biomedcentral.com/bmcevolbiol/

Nancy Ross-Flanigan | Newswise Science News
Further information:
http://umich.edu/news/index.html?Releases/2009/Dec09/venom

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>