Stories of climbing fishes in the Luvilombo River in the Democratic Republic of the Congo have been around for a long time. Yet until now, no one had documented or scientifically proven this astonishing behaviour. When the water level is right, a small natural wonder can be observed at the Luvilombo waterfall, which is around 15 metres high: Smaller individuals of the species Parakneria thysi work their way up the steep rocks bit by bit. In doing so, they can even overcome overhanging sections! Once they reach a flatter spot, it’s time for a break. No wonder: the ascent can take more than nine hours and requires an enormous amount of energy. But how do the animals manage it at all? Researchers have discovered that the animals’ pelvic and pectoral fins are equipped with numerous tiny hooks, which act as small climbing aids and give the fish a grip on the wet rock. Why they go to such lengths is not yet fully understood. Perhaps they find more food further upstream. Perhaps they also escape predators lurking further down the river.
