Individual movement behaviour and habitat use of a small-sized cypriniform (Telestes muticellus) in a mountain stream

Knowledge about the biology and ecology of species is fundamental for their management and conservation. Despite this, many fish species and life stages are understudied, and there is a great need for research efforts to understand their ecology. Italian riffle dace (Telestes muticellus; order Cypriniformes) is a small-sized (< 15 cm) stream fish native to the Italian peninsula. There is a scarcity of research on its ecology and behaviour. In this study, we explored the movement ecology of Telestes muticellus in a Mediterranean mountain stream in Northern Italy using passive integrated transponder (PIT) telemetry. Over 15 months, 267 fish were located 2–27 times. Most fish remained stationary, while a few roamed over several hundreds of meters. Fish covered a larger linear range during spring and autumn than during other seasons. T. muticellus showed a strong preference for pools, and this preference was strongest during summer. We observed no differences in habitat use and movements between day and night, and fish size had no major effect. Within pools, many T. muticellus displayed remarkably small home ranges (median 8 m2). Fish increased their linear ranges over a period of flood events, indicating that high-flow events may be important for the downstream and upstream dispersal of T. muticellus in small mountain streams.