Fish that can survive out of water found in Bolivia

By Yolanda Salazar
La Paz, Jul 14 (EFE).- A new fish species discovered by Bolivian researcher Heinz Arno Drawert can survive out of water for hours at a stretch thanks to an ability to alter its respiration.
Drawert first spotted the Moema juanderibaensis (its scientific name) during the 1990s in Santa Rosa del Sara, a community in the eastern province of Santa Cruz.
But, he told EFE, it was only in 2018 that he was able to embark on a thorough study of the Moema juanderibaensis and other members of the Rivulidae family in Bolivia under the auspices of the Noel Kempff Mercado Museum of Natural History in Santa Cruz city.
Last year, Drawert published his findings in Neotropical Ichthyology, a Brazilian scientific journal.
The Moema juanderibaensis is a brightly colored fish that inhabits temporary bodies of water, known in eastern Bolivia as “curichis,” Drawert said.
Like other members of the Rivulidae family, the Moema juanderibaensis lay their eggs in the muddy bottom of swamps and puddles.
When the water disappears, the adult fish eventually die, but the eggs can survive for up to three years, hatching when the water returns, Drawert said.
“Their eggs can withstand drought and they bury their eggs at the bottom of the puddle, inside the mud or the earth, and they leave them there and the puddle can dry up, but nothing happens to the eggs,” he explained.
Drawert has observed that adult fish “voluntarily” leave the water to perch on leaves or plants for up to four hours, usually because they feel threatened by the presence of predators below the surface.
And while outside the water, the Moema juanderibaensis breathes through its skin – in the manner of amphibians – rather than using its gills, the scientist said.
Despite their adaptability, the forest-dwelling fish are “very sensitive to change in their habitat,” Drawert said, adding that neither the adults nor the eggs can survive when trees are chopped down.
“The last 20 to 30 years there has been an enormous expansion of forest-cutting, a great part of the habitat no longer exists, we can easily say that 60-70 percent of their natural habitat disappeared,” he said.
EFE ysm/dr