Spawning strategies in cypriniform fishes in a lowland river invaded by non-indigenous European barbel Barbus barbus

<jats:title>Abstract</jats:title><jats:p>Spawning strategies of lowland river fishes include single spawning, where reproduction generally occurs in early spring to provide 0+ fish with an extended growth season through the summer, but with a high risk of stochastic mortality events occurring, such as early summer floods. This risk can be reduced by multiple or protracted spawning strategies, where 0+ fish are produced over an extended period, often into mid-summer, but with the trade-off being a shorter growth season. The spawning strategies of cypriniform fish were explored in the River Teme, a spate river in Western England, which has non-indigenous European barbel <jats:italic>Barbus barbus</jats:italic> present. Sampling 0+ fish in spring and summer and across three spawning periods, <jats:italic>B. barbus</jats:italic>, chub <jats:italic>Squalius cephalus</jats:italic> and minnow <jats:italic>Phoxinus phoxinus</jats:italic> always revealed multiple spawning events, with 0+ fish of &lt; 20 mm present in samples collected from June to August. Fish below 20 mm in August remained relatively small by the end of their growth season (October). For dace <jats:italic>Leuciscus leuciscus</jats:italic>, only single spawning events were evident, but with 0+ dace always being relatively large. Therefore, multiple spawning appears to be a common strategy that provides resilience in 0+ fish against stochastic mortality events in lowland rivers.</jats:p>