Shellear Fish: The Remarkable Climbers of Luvilombo Falls

The shellear fish (Parakneria thysi), a species native to the Democratic Republic of Congo, has recently gained attention for its extraordinary ability to climb waterfalls. This behavior was first observed by Auguste Chocha Manda, a researcher at the Université de Lubumbashi, who documented the phenomenon at Luvilombo Falls over 17 years ago. However, it wasn't until recent studies led by Pacifique Kiwele Mutambala and Emmanuel Vreven that this climbing behavior was filmed and scientifically documented for the first time.

NPRFor 50 years, there have been rumours of these fish climbing waterfalls. Scientists just filmed them doing it for the first time

Mutambala's research, conducted during the rainy seasons of 2018 and 2020, revealed that only smaller shellear fish, measuring a couple of inches long or less, successfully ascend the 50-foot rock face. Larger fish are believed to be too heavy to climb effectively. The fish utilize their pelvic fins for support and their pectoral fins, equipped with tiny hook-like projections, to grip the rock surface. Their climbing technique involves lateral undulations, akin to swimming, allowing them to navigate the vertical terrain. The entire ascent can take approximately ten hours, with the fish frequently pausing to rest and recover energy.

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The climbing behavior of the shellear fish is thought to be part of a migratory pattern, potentially aimed at accessing better feeding grounds or avoiding predators upstream. This migration is critical for maintaining the genetic connectivity between upstream and downstream populations. However, human activities, such as water diversion for irrigation and illegal fishing practices, pose significant threats to their habitat. Vreven emphasizes that without a consistent water supply, the survival of the shellear fish is jeopardized.

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The findings of Mutambala and his colleagues highlight the importance of protecting the Luvilombo Falls ecosystem. Migratory fish like the shellear are at a higher risk of endangerment compared to non-migratory species. The researchers advocate for recognizing the falls as a natural monument or an ecosystem of national interest to ensure the conservation of this unique species and its habitat.

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The research team has underscored the need for further studies to understand the ecological implications of the shellear's climbing behavior. They assert that protecting the waterfalls is essential for the biodiversity of the region, as the loss of this habitat could lead to the decline of the shellear population.

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• “The ability of shellears to climb waterfalls has been known anecdotally for over 50 years,” — Pacifique Kiwele Mutambala, Researcher

For 50 years, there have been rumours of these fish climbing waterfalls. Scientists just filmed them doing it for the first time

• “Migratory fish are several times more at risk of endangerment or extinction than fish that don't migrate,” — Steven Cooke, Fish Ecologist

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• “there are no fish.” — Emmanuel Vreven, Ichthyologist

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The shellear fish's climbing behavior not only fascinates researchers but also serves as a critical reminder of the delicate balance within aquatic ecosystems. As studies continue, the hope is that increased awareness and conservation efforts will help protect these remarkable fish and their unique habitat at Luvilombo Falls.

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