Trait-Based Prediction of Conservation Status of North American Small-Bodied Minnows (Leuciscidae) and Darters (Percidae)

With the rapid decline of aquatic biodiversity, conservation tools such as captive breeding for reintroduction are becoming more common. A major challenge, however, lies in determining which species should be prioritized for such efforts. One effective method is to assess species' life history and ecological traits, which are often associated with extinction risk and can provide critical insights for guiding species prioritization. In this study, we assessed all small-bodied minnow and darter species in North America (i.e., Canada, the United States and Mexico) to determine if life history and ecological traits could predict their conservation status. We analysed 13 life history and ecological traits in relation to the IUCN conservation status for 220 species of minnow and 183 species of darters. For minnows, traits such as substrate, climatic zone, diet, feeding location, total length and maximum water temperature were associated with a higher risk of being threatened. For darters, the traits associated with an increased risk of being threatened were climatic zone and total length. Taken together, this study identifies key life history and ecological traits that influence the conservation status of small-bodied fishes and provides actionable insights for prioritizing species for captive breeding programmes. These findings can guide conservation practitioners in developing species-specific, proactive recovery strategies to prioritize species at risk and enhance conservation efforts before they become threatened in the wild.