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 Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory

nachricht ‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

Im Focus: A transistor of graphene nanoribbons

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."

Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

Making fuel out of thick air

08.12.2017 | Life Sciences

Rules for superconductivity mirrored in 'excitonic insulator'

08.12.2017 | Information Technology

Smartphone case offers blood glucose monitoring on the go

08.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>