Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Invasive lionfish likely safe to eat after all

01.08.2014

Scientists have learned that recent fears of invasive lionfish causing fish poisoning may be unfounded. If so, current efforts to control lionfish by fishing derbies and targeted fisheries may remain the best way to control the invasion. And there's a simple way to know for sure whether a lionfish is toxic: test it after it's been cooked.

Pacific lionfish were first reported off the coast of Florida in the 1980s, and have been gaining swiftly in number ever since. They're now found in marine habitats throughout the tropical and subtropical Western Atlantic, Caribbean and Gulf of Mexico, threatening native fishes with their voracious appetites and unchecked population growth.


This is an invasive lionfish speared and placed on ice, ready to be filleted and cooked.

Credit: Christie Wilcox, Hawaii Institute of Marine Biology, UH SOEST.

Targeted removal is the only management strategy that seems to help, and many hope to establish a food fishery to increase the fishing pressure on these ravenous predators. Such a strategy is in jeopardy, though, because the FDA added the lionfishes Pterois volitans and Pterois miles to their ciguatera watch list, a catalog of species that may contain the potentially fatal foodborne toxin, citing evidence that lionfish have positively tested for ciguatera. As of July 2014, though, there are no known cases of ciguatera from eating lionfish.

A new study published in Environmental Biology of Fishes may have an explanation for that. Lead author Christie Wilcox of the University of Hawaii thinks there may be a different reason that so many lionfish are coming up positive on ciguatoxin tests: venom proteins might act as ciguatoxin mimics.

"We already know lionfish produce bioactive compounds—just ask anyone who has ever been stung," she said. "We just don't know a whole lot about what those compounds are or whether they occur outside of the venomous spines."

Ciguatera fish poisoning is a foodborne illness caused by eating certain reef fish whose flesh contains ciguatoxins, small lipid toxins originally produced by single-celled dinoflagellates that live on or near the reef. The toxins themselves are colorless, odorless and tasteless, and cannot be destroyed or removed through any normal process of fish preparation, thus accurate testing is the only way to ensure food is safe to consume. Most current test methods are unable to actually detect the toxin compounds, and instead, focus on what the toxins do to cells to determine if a fish is contaminated.

It struck Wilcox that, at the cellular level, lionfish venom might be difficult to distinguish from ciguatoxins because they have similar activities. She took muscle, skin, spine and liver tissue from invasive lionfish and used antibodies against stonefish venom to detect the presence of venom proteins—and found them. "Lionfish express venom-like proteins throughout their bodies," she said. "We don't know exactly what these proteins are or what they're doing, but we know they're there."

Because tissues for ciguatoxin testing undergo preparation in the laboratory to concentrate the toxins, Wilcox further tested whether these proteins made it through common lipid extraction methods used in ciguatoxin testing. Though the amount was reduced, they could still be detected. "These proteins could be making their way into ciguatoxin test dishes," said Wilcox, "and if they are, there's a chance they're messing up our tests."

The presence of these proteins in your fillets is nothing to worry about, though, says Wilcox. "Unlike ciguatoxin, lionfish venom degrades with at room temperature, let alone with heat, so you have nothing to fear from a lionfish dinner."

The negative impact of false positives is the real issue, says co-author Mark Hixon. "Just the fear and rumor of ciguatera is enough to close a fishery, and that's the last thing we need as we try to encourage people to fight lionfish explosion by eating the invader."

Wilcox is quick to note that the work does not prove that lionfish are perfectly safe. "No one is debating that lionfish could be ciguatoxic," says Wilcox. "But there's no reason to think they're any more ciguatoxic that groupers or other smaller predators in an area. If they're popping positive more often than species with the same diet, that indicates there's something fishy going on."

Wilcox hopes that the research will urge researchers to carefully examine their testing protocols to ensure that the proteins she discovered in lionfish tissues don't lead to unwarranted fear of lionfish consumption. "The first, easy step is to cook or boil lionfish samples prior to ciguatoxin testing. Heat degrades the venom proteins, ensuring they don't cause any problems."

###

Christie L. Wilcox and Mark A. Hixon, 2014. False positive tests for ciguatera may derail efforts to control invasive lionfish, Environmental Biology of Fishes, doi: 10.1007/s10641-014-0313-0.

The School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa was established by the Board of Regents of the University of Hawai'i in 1988 in recognition of the need to realign and further strengthen the excellent education and research resources available within the University. SOEST brings together four academic departments, three research institutes, several federal cooperative programs, and support facilities of the highest quality in the nation to meet challenges in the ocean, earth and planetary sciences and technologies.

Marcie Grabowski | Eurek Alert!
Further information:
http://www.hawaii.edu

Further reports about: Biology Environmental Fishes Hawaii Lionfish Wilcox eat fishery invasive proteins species toxins venom

More articles from Health and Medicine:

nachricht New leukemia treatment offers hope
23.09.2016 | King Abdullah University of Science and Technology

nachricht Alzheimer’s: Cellular Mechanism Provides Explanation Model for Declining Memory Performance
21.09.2016 | Deutsches Zentrum für Neurodegenerative Erkrankungen e.V. (DZNE)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>