Researchers have discovered a new species of giant fish arapaima in the central Amazon waters of Brazil.
The finding made scientists wonder what species remain undiscovered in the area and highlighted the potential harm that can come about when species are removed from their natural habitat, a SUNY College of Environmental Science and Forestry (ESF) news release reported.
"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," Doctor Donald Stewart of the SUNY-ESF, who made the discovery, said.
Arapaima have been a staple of the Amazon fishing industry for about 200 years.
"Arapaima have high economic, cultural and scientific value, but their diversity has been overlooked for too long," Stewart said.
In the mid 1800's four species of arapaima were identified. In 1868 a scientist named Albert Günther made the claim that there was really only one species of arapaima, and his view became the leading opinion.
"Until this year, no taxonomist has questioned Günther's opinion about these iconic fishes," Stewart wrote. "If you're going to do conservation biology, you have to be sure about the taxonomy of the animals being studied. If each study area has a different species, then results from one area should not be applied to manage populations in the next area."
After studying preserved specimens at the National Museum of Natural History in Paris, Stewart found the four originally distinguished Arapaima were in fact different species. The researcher also found an additional species at the Instituto Nacional de Pesquisas da Amazônia in Manaus, Brazil.
The new species has a uniquely shaped sensory cavity on its head, a different color pattern, and an additional sheath covering a section of its dorsal fin.
"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."
The Arapaima have been grossly overfished in the Amazon for centuries.
"Abundances of arapaima in large expanses of their natural habitat today are near-zero, largely as a consequence of overfishing," Doctor Leandro Castello, an authority on arapaima in Brazil, said. "The likely impacts of this magnitude of overfishing on species diversity are not good."
