Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientist Reports New Species of Giant Amazonian Fish

16.10.2013
Discovery highlights hazards of relocating animals among habitats

A new species of the giant fish arapaima has been discovered from the central Amazon in Brazil, raising questions about what other species remain to be discovered and highlighting the potential for ecological problems when animals are relocated from their native habitats.


These arapaima, which were photographed in a public aquarium in the Ukraine, appear to be the new species recently described by Dr. Donald Stewart of SUNY-ESF. They clearly show the elongated sensory cavity as a dark bar on the lower side of the head, a feature that is known only for A. leptosoma.

“Everybody for 160 years had been saying there’s only one kind of arapaima. But we know now there are various species, including some not previously recognized. Each of these unstudied giant fishes needs conservation assessment,” said Dr. Donald Stewart of the SUNY College of Environmental Science and Forestry (ESF), who made the discovery.

The discovery was reported in a paper Stewart recently published in the journal “Copeia.”

For two centuries, arapaima have been among the most important commercial fishes in freshwaters of the Amazon. “Arapaima have high economic, cultural and scientific value, but their diversity has been overlooked for too long,” Stewart said.

Four species of arapaima were recognized in the mid-1800s, but in 1868, Albert Günther, a scientist at the British Museum of Natural History, published an opinion that those were all one species, Arapaima gigas. Over time, Günther’s view became the prevailing wisdom.

“Until this year, no taxonomist has questioned Günther’s opinion about these iconic fishes,” Stewart wrote.

That lack of inquiry changed, however, when Stewart began studying the genus in Guyana and Brazil. “If you’re going to do conservation biology, you have to be sure about the taxonomy of the animals being studied,” he said. “If each study area has a different species, then results from one area should not be applied to manage populations in the next area.”

Delving into scientific literature from the 19th century and examining original specimens preserved at the National Museum of Natural History in Paris, Stewart concluded that all four of those originally described species were, in fact, distinct. Stewart re-described one of those original species (in a paper published in the March issue of “Copeia”) and summarized status of the other three species. Stewart’s most recent discovery came when he examined preserved arapaima at the Instituto Nacional de Pesquisas da Amazônia in Manaus, Brazil. This new description brings the total number of species to five.

The recently identified specimen was collected in 2001 near the confluence of the Solimões and Purus rivers in Amazonas State, Brazil. It is distinguished from all other arapaima by several characteristics, including the shape of sensory cavities on the head, a sheath that covers part of the dorsal fin and a distinctive color pattern. Its scientific name, A. leptosoma, is in reference to its slender body.

“Failure to recognize that there are multiple species has consequences that are far reaching,” Stewart said. “For example, there is a growing aquaculture industry for arapaima, so they are being moved about and stocked in ponds for rearing. Eventually pond-reared fishes escape and, once freed, the ecological effects are irreversible. A species that is endangered in its native habitat may become an invasive species in another habitat. The bottom line is that we shouldn't be moving these large, predatory fishes around until the species and their natural distributions are better known. Given the uncertainties, precaution is needed.”

There is also the problem that arapaima are the most historically overexploited fishes of the Amazon Basin, having been subjected to intense and largely uncontrolled fishing pressure for at least a century. “Abundances of arapaima in large expanses of their natural habitat today are near-zero, largely as a consequence of overfishing,” said Dr. Leandro Castello, an authority on arapaima in Brazil. “The likely impacts of this magnitude of overfishing on species diversity are not good.”

Stewart said the newly discovered species is on display in a public aquarium in the Ukraine, where it was identified as Arapaima gigas, the single name that has been applied to all arapaima for the past 140 years. It thus appears this new species already is being cultured and exported from South America, but under the wrong name.

Stewart’s work was supported by ESF and the National Geographic Society.

Claire B. Dunn | Newswise
Further information:
http://www.esf.edu

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>