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 Correct connections are crucial
26.06.2017 | Charité - Universitätsmedizin Berlin

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>