New varieties of South American darter fish have been documented in the Brazilian region of Apuí. But deforestation in the area means they could soon become extinct
Two recently described Amazonian fish species may already be doomed to extinction.
When Murilo Pastana at the Smithsonian National Museum of Natural History in Washington DC set out with a group of colleagues looking for fish in the less explored regions of the Amazon River basin, he didn’t know what they would find. A few days into the 2015 expedition, Pastana pulled a net from the water and was surprised to see small vibrant orange fish in the plastic net. The combination of long reddish fins and a dark spot in front of the fish’s tail was unlike anything he had seen before.
“We quickly realized this fish was different,” says Pastana. “We were so excited, like little children.”
The 3cm long fish, now called Poecilocharax callipterus, was plucked from a stream in the Brazilian region of Apuí. The researchers then scoured the surrounding area to see if the fish lived elsewhere. It was then that they found a second previously undescribed species of fish among the tangled tree roots of a muddy stream. “I said, ‘Wait! There are two of them, ”says Pastana.
Unlike the orange fish they had previously found, this new specimen shared the subtle yellow-brown coloration of other fish species in the area. Once a lab analysis confirmed the new species, the team named the 2-centimeter-long fish Poecilocharax rhizophilus for his apparent love (“ fil “) Of roots (“ riz “).
Genetic analyzes have since verified that both fish belong to the genus Poecilocharax, a subgroup of small freshwater fish known as South American dates. The species are the first additions to the genus since 1965.
In 2016 Pastana and her colleagues returned to carry out another in-depth research, which confirmed what she feared: P. callipterus it was limited to a single watercourse with approximately 4 square kilometers of habitat. P. rhizophile it was in a slightly less severe position, with a range of about 50 square kilometers.
In the six years since that exhibition, the forest that houses the two species of fish has been razed to make room for livestock, crops and gold mining, which decimate native flora and fauna.
thinks Pastana P. rhizophile it is probably still resisting, but fears that even a small amount of human development may have destroyed the limited habitat of P. callipterus.
“Sometimes, when we get to a region, it’s on fire because they have to clear the forest for livestock,” he says.
Pastana hopes this discovery will spur legal protections for fish, but admits it will be an uphill battle. He thinks that the bigger, the brighter P. callipterus he can find a home among aquarium enthusiasts, who could at least support the species even if his native home is destroyed. “It’s not the best … but maybe that’s one way this species will survive,” she says.
Journal reference: Zoological journal of the Linnea Society DOI: DOI: 10.1093 / zoolinnean / zlac026
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