Bumblebee on the rocks: Massive aggregation, migratory and climbing behaviour of a small Neotropical catfish

Rhyacoglanis are small catfish species of the family Pseudopimelodidae, Siluriformes, commonly known as bumblebee catfishes. Despite their broad distribution, the species are rare, and little is known about their biology and behaviour. Here, we report, for the first time, a remarkable massive aggregation and migratory and climbing behaviour of Rhyacoglanis paranensis. These findings highlight the importance of field observations in understanding small migratory fishes' ecological role and conservation needs, particularly in the context of potential threats posed by habitat fragmentation and river damming.