Scientists stunned as catfish climb waterfalls in first-ever sighting

A remarkable display of nature’s resilience was captured on camera where thousands of bumblebee catfish (Rhyacoglanis paranensis) were seen climbing waterfalls in southern Brazil.

This marks the first documented case of this rare species. The exceptional event captured on video and detailed in a new peer-reviewed study has stunned scientists and provided unprecedented insights into the mysterious lives of these little-known fish.

The incident was noticed by Brazil's Environmental Military Policy first when they observed an unusual gathering of fish near their headquarters in Mato Grosso do Sul State in November 2024.

Later, researchers were called, and they witnessed thousands of small, orange, and black catfish gathered at the base of a waterfall, slowly climbing the rocky walls over a 20-hour period.

Before this, this species had never been seen in such large numbers or climbing waterfalls.

Upon observing the timings, the study suggests that the fish were migrating upriver to reproduce.

While most were bumblebee catfish, a few individuals from three other fish species were also spotted climbing.

The video shows the catfish were seen wiggling vertically up near vertical rock faces, even in the dark of night.

These species are poorly studied as they are very rare to witness. It makes this incident a breakthrough in ichthyology (fish science).

Small fish have an unpredictable nature, due to which it's hard to study their migration patterns as it is very brief.

The findings showcase the hidden behavior of South America’s diverse freshwater ecosystems.