New Species of Giant Fish Discovered in Brazil

Researchers have discovered a new species of a giant fish from Brazil .

The researchers from SUNY college of Environmental Science and Forestry (ESF) discovered a new species of arapaima, the largest fish in South America as it grows to a length of more than 2 meters. Arapaimas have high cultural, scientific and economic value but the diversity of these fish have been overlooked for centuries.

Native to the Amazon River in Brazil, the commercial fishing of arapaima has been banned by the Brazilian government due to its near extinction. This new discovery highlights the ecological problems that can crop up when animals are relocated from their native habitats.

 "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," Dr. Donald Stewart of the SUNY College of Environmental Science and Forestry (ESF), who made the discovery, said in a press statement.

In the mid 1800s only four species of arapaima were known. But in 1869 a scientist at the British Museum of Natural History, Albert Gunther, highlighted the fact that all those were from one species called Arapaima gigas.  Since then there have been no further findings.

But things changed when Stewart started studying the genus of the fish from 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."

By examining specimens at the National Museum of Natural History in Paris and by referring to literature from the 19^th century, Stewart concluded that all four of the originally described species were in fact different. He went about re-describing one of the specie and provided a summary of the remaining three species. He concluded this by examining the preserved arapaima at the Instituto Nacional de Pesquisas da Amazônia in Manaus, Brazil.  This new finding presents a total of five species.

The recently discovered specimen was collected in 2001 from the Amazonas state river. It was different from all other arapaima not just in the shape of the sensory cavities on its head but also the sheath that blankets a part of the dorsal fin. Based on its slender body, the newly discovered giant fish is called A.leptosoma.

"Failure to recognize that there are multiple species has consequences that are far reaching," Stewart said

The newly discovered specie is on display at the public aquarium in Ukraine and earlier it was identified as Arapaima gigas.

Dr. Leandro Castello, an authority on arapaima in Brazil concluded saying, "Abundances of arapaima in large expanses of their natural habitat today are near-zero, largely as a consequence of overfishing. The likely impacts of this magnitude of overfishing on species diversity are not good."

The findings were published in Copiea earlier this year.