The river looked calm, yet locals swore it once swallowed canoes without leaving a ripple. Deep in the Ecuadorian Amazon, the Santiago River hid behind its murky surface like a wild trickster. Few outsiders dared to explore its most remote stretches, and those who tried came back with stories of currents that tugged at their boats and shadows that moved beneath them. Still, the river kept its mysteries sealed for generations until a small Indigenous community revealed something unexpected. The people of Kaputna uncovered a hidden world filled with fish species that scientists never imagined were living there. The truth was stranger and richer than anyone guessed.
The River that Hid from the World
The Shuar community of Kaputna lives in a place with no roads, no shops and no quick way to reach the outside world. Their settlement sits along the Santiago River, which many people saw as difficult and risky to explore. Local legend said the river swallowed canoes, and residents believed its fast water needed to be respected. Reaching Kaputna means a long bus ride, a bumpy ride in a truck and a tense journey in a wooden canoe powered by a small motor. The heat hits hard, the currents twist sharply and fallen trees slide past the boat like giant spears.
But the people of Kaputna know the river better than anyone. Their fishermen read the water like others read maps. They recognise every sharp turn and rocky patch. They grew up watching the behaviour of fish beneath the brown water, even when no one else could see a single thing below. For years, researchers said the Santiago basin was one of the least known areas in the Amazon. That changed when the Kaputna community agreed to help reveal the river’s secrets.
The Discovery that Shocked Scientists
In 2021, researchers invited Kaputna fishermen to help study the fish of the Santiago River. The community’s knowledge impressed the scientists almost immediately. The locals collected specimens, recorded details through a mobile app and shared observations that came from a lifetime on the water. Working together, they documented an amazing 144 species in an area of just 21 square kilometres.
The team found 77 species never before recorded in the wider region. They also discovered five species that had never been found in Ecuador. One of these was an armoured fish called Peckoltia relictum. Experts had no clue it lived anywhere inside Ecuador. Another catfish with bold black stripes may even be a new species to science, although researchers are still analysing it. DNA tests helped confirm the identity of the most unusual specimens and corrected early assumptions. In one case, scientists first thought they had found a completely new species but later learned it had been described years earlier.
Kaputna residents weighed the fish, measured them and stitched labels to the preserved samples. They turned a small room into a simple laboratory and took on tasks usually handled inside large research centres. Several locals admitted they never expected to do scientific work. One fisherman said he always sensed that the river held something important to share. Researchers later said the project showed a meaningful shift in recognising the essential role of Indigenous contributors. The Kaputna team did far more than assist. Their knowledge shaped the entire study.
A Window Into a Changing Amazon
Scientists have warned for years that freshwater fish in the Amazon face major threats. Habitat loss, mining pollution and changes to river health have caused freshwater fish numbers to drop sharply around the world. Reports show global migratory freshwater fish populations have fallen by more than 80 percent over the last fifty years, with the steepest decline happening in Latin America. Even with these challenges, the Amazon still holds the greatest variety of freshwater fish on Earth, and experts believe thousands more species remain undiscovered.
This is why the Kaputna discoveries matter so much. They do more than introduce new species. They highlight how much the Amazon still hides. They show how Indigenous wisdom can work with scientific research to protect wildlife and support communities. Many families in the region depend on fish for food, so understanding the river is crucial for their future. The Kaputna community proved that conservation is strongest when local people help lead the work.
The Man Who Saw the Future
One fisherman, Germán Narankas, shared that he once saw visions during a traditional ayahuasca ritual. He believed he would someday take part in a project that involved the river. Years later he joined the scientific team and became a co author of the study. He felt proud when he saw his name in the published paper. The experience affected him so deeply that he returned to high school in 2025. He hopes to study biology and continue exploring the Santiago River.
The river still hides many secrets. Upstream, clear green waters in the Yaupi tributary reveal rocks and flickers of silver fish. Locals say some stretches remain dangerous even today. Yet thanks to the Kaputna community, the world now knows that the Santiago River is not empty at all. It is one of the richest freshwater habitats ever recorded, and its wonders are only beginning to surface.
