Italian riffle dace

biology_ecology

A total of 98 tagged fish were monitored and studied for their apparent survival and movements; 24 in the intermittent reach and 74 in the perennial reach (Tab. 1). There were no differences in lengths between fish from the intermittent and perennial reach groups for 2022 (Mann-Whitney U = 135, W = 631, p - value = 0.90) and 2023 (Mann-Whitney U = 261, W = 1164, p - value = 0.33). Over 2 yr, 21 from 24 fish present in the intermittent reach, successfully migrated upstream and were tracked in the perennial reach during the dry periods (Fig. 2). Two fish were not detected following the dry-up process, and one pit tag was found in the dry riverbed of the intermittent section. These three fish, one in the year 2022 and two in the year 2023, were considered mortalities. In the perennial group, before the onset of the dry periods, 74 fish, comprising 32 in the year 2022 and 34 in the year 2023, were tracked and confirmed to be alive. However, after drying, ten tags that disappeared were likely associated with mortality events, with one mortality in 2022 and nine in 2023. Differences in apparent survival were not observed between the intermittent and perennial fish groups in both 2022 (Fi

Navigating the drought: upstream migration of a small-sized Cypriniformes (Telestes muticellus) in response to drying in a partially intermittent mountain stream