Shellear Fish Climbs 15-Metre Waterfalls in Congo

Scientists have recently documented a remarkable behaviour of the shellear fish, a small freshwater species capable of climbing vertical waterfalls up to 15 metres high in the Democratic Republic of Congo. This discovery highlights the extraordinary adaptability of aquatic species in extreme environments and has drawn attention to the ecological uniqueness of the Congo Basin.

About Shellear Fish

The shellear fish, scientifically known as “Parakneria thysi”, is a freshwater species found in the upper Congo Basin, particularly around the Luvilombo Falls on the Luvilombo River. It belongs to the benthopelagic category, meaning it inhabits both the bottom and mid-water layers of freshwater ecosystems. These fish are relatively small, typically measuring between 37 mm and 48 mm, though they can grow up to approximately 96 mm in length.

Unique Climbing Adaptations

What makes the shellear fish exceptional is its ability to scale steep waterfalls. This feat is enabled by specialised physical adaptations, including tiny hook-like projections on pads located on their pectoral and pelvic fins. Additionally, hypertrophied muscles provide the strength required to support their body weight against strong water currents. These features allow the fish to maintain grip and gradually move upwards along wet rock surfaces.

Reasons Behind Waterfall Climbing

Researchers suggest that this climbing behaviour is driven by survival needs. By moving upstream, the fish can access habitats with reduced competition and fewer predators. Such environments may also offer better breeding conditions and improved availability of resources, enhancing their chances of survival.

Important Facts for Exams

• Shellear fish is scientifically known as “Parakneria thysi”.
• Found in the upper Congo Basin, especially Luvilombo Falls.
• Capable of climbing waterfalls up to 15 metres high.
• Adaptations include hook-like fin projections and strong muscles.

Threats and Conservation Concerns

Despite its unique abilities, the shellear fish faces significant human-induced threats. Illegal fishing practices, particularly the use of fine-mesh mosquito nets, pose a major risk as they easily capture these small fish. Additionally, water extraction for irrigation has led to reduced water levels in the Luvilombo River in certain years, threatening the species’ habitat and survival.