Nearly one‐third of extant freshwater fish species, which account for over 50% of global fish diversity, are at risk of extinction. Despite their crucial ecological and socioeconomic importance, the extinction of freshwater fishes remains under‐researched on a global scale. This is a comprehensive assessment of taxonomic, spatial, and temporal patterns of freshwater fish extinctions while identifying key extinction drivers and driver synergies. Using data from the International Union for Conservation of Nature Red List, 89 extinct freshwater fish and 11 extinct in the wild were analyzed. Taxonomic statistical analysis revealed the disproportionate impact on Cyprinidae, Leuciscidae, and Salmonidae. Estimated globally for the period 1851–2016, the modern extinction rate for freshwater fishes stands at 33.47 extinctions per million species‐years (E/MSY), more than 100 times greater than the natural background extinction rate of 0.33 E/MSY. Extinction rates, when calculated per continent using the number of extinct species and the total number of species per continent, indicated that North America has the highest extinction rate (225.60 E/MSY), followed by Europe (220.26 E/MSY) and Asia (34.62 E/MSY). Although Africa is less affected, it still shows a 42‐fold increase over the background rate. Bayesian modeling, reflecting cumulative species extinctions, indicated a strong association of North America and Asia with species loss (37 and 34 extinctions, respectively), a moderate one for Europe (20 extinctions) and a weak association of Africa (eight extinctions). Natural system modification, pollution, and invasive species emerged as the primary extinction drivers, often acting synergistically. Temporal trends indicate an acceleration in extinctions since the mid‐20th century. This study highlights that, despite recent increases in conservation efforts, freshwater fish extinctions continue to rise, indicating the urgent need for integrated conservation strategies. Without immediate action, many species currently at risk may soon follow the same trajectory of extinction as the 100 extinct freshwater fishes of this study.

The European Union of Aquarium Curators (EUAC) boasts a membership of 150 dedicated individuals, standing as a vital cornerstone within the European public aquarium community. Since 2004, the EUAC Conservation Fund has granted over a quarter of a million euros to approximately 50 conservation projects spanning the globe. These initiatives, diverse in nature and scale, have yielded tangible impacts on local populations and their focal species. This paper delves into the outcomes of these conservation endeavors and proposes enhancements to ensure that the funding is unequivocally channeled towards conservation efforts. One resounding observation gleaned from the array of projects spotlighted in this study is the profound community engagement that emerges, irrespective of the final project outcomes. These endeavors serve as a catalyst for local communities, shedding light on subjects that would otherwise remain shrouded in obscurity. Furthermore, the EUAC-backed projects illuminate the expansive reach of public aquarium initiatives, transcending the confines of acrylic tank walls and institutional boundaries to resonate globally, heightening local awareness about the imperative to safeguard biodiversity. These findings underscore a prospective trajectory for both the EUAC and the public aquaria it comprises: an intensified advocacy and collaboration with legislative bodies to fortify in situ conservation measures. In essence, it is imperative that the public comprehends the pivotal role played by aquaria in preserving a multitude of species and acknowledges that their visits directly contribute to funding projects aimed at safeguarding species within their natural habitats.

Alien fish invasions are causing devastating impacts on native freshwater fauna; thus, rigorous, non-invasive and cost-effective biomonitoring of lotic and lentic freshwaters to design and implement appropriate prevention and control measures is now a priority. In this study, we used a species-specific qPCR eDNA assay to monitor two of the most invasive fish species (Gambusia holbrooki and Pseudorasbora parva) in 15 river basins of Greece and validated these results with conventional fish sampling as well as existing field sampling data. Our monitoring provided new records of invasive species indicating basins for rigorous future monitoring and possible eradication attempts. The eDNA proved more sensitive as a detection tool (56% detection rate) compared to conventional electrofishing (50% detection rate) for G. holbrooki. In contrast, it proved less sensitive for detecting P. parva (38% accuracy) compared to electrofishing (44% accuracy), as evident by the two locations where the eDNA failed to detect the target species. Our study illustrates the potential of the eDNA method for regular, standardised monitoring of riverine habitats for invasive fish species by local managers for early detection. Finally, we discuss the application of eDNA in management interventions for identifying invasive species’ hotspots for management prioritisation, for early detection of invaders and for the monitoring of eradication/control actions.

DNA barcodes (COI) of Troglocobitis starostini, endemic to a single site in Turkmenistan, were analysed and put into the taxonomic context of the large group of nemacheilid loaches known from Western and Central Asia. All applied phylogenetic tree-based analyses place the species into the genus Paracobitis. This finding supports previous morphological studies. While the exact position of Troglocobitis starostini within Paracobitis was not resolved unambiguously, it was constantly recovered within Paracobitis, irrespective of the tree reconstruction method applied. With a minimum interspecific K2P distance of 7.19% P. persa was the closest hit in our dataset, which comprised a total of ten species of Paracobitis, which showed an average interspecific K2P distance of 5.43% (range 2.78–9.44%).

Freshwater biodiversity is under immense pressure globally, with invasive species among the primary drivers of extinction risk. We tested whether urban aquatic habitats can serve as refugia for threatened freshwater fish from invasive species' pressure, focussing on the translocation of a critically endangered killifish (Corfu killifish, Valencia letourneuxi ) to a spring‐fed peri‐urban pond in northwestern Greece. Urban habitat suitability was assessed using the REVIVE‐POLIS feasibility analysis tool, which incorporates conventional ecological criteria (water and biological quality, species‐specific habitat requirements, and invasive species pressure) alongside urban‐specific criteria including hydrological stability, food web structure and surrounding land use. The tool supported the suitability of the release site and indicated its utility in urban conservation planning. The translocation involved a two‐stage transfer of a total of 84 adult killifish spawners into the recipient pond across 2021 and 2022, corresponding to an estimated introduction density of 1.12 translocated inds m ⁻² . Post‐release monitoring in 2022 utilizing electrofishing confirmed establishment at the release site (density 0.83 inds m ⁻² ), as evidenced by the presence of larvae and juveniles. Subsequent monitoring in 2024 and 2025 using underwater cameras recorded cohorts of approximately 30 individuals (density 0.71 inds m ⁻² ). These spanned multiple age classes on both occasions, suggesting persistence and recruitment for ≥3 years after the initial release. As a single‐site case study, these findings should be interpreted cautiously; nevertheless, they indicate that carefully selected and managed urban aquatic refugia may complement conventional approaches for threatened fishes exposed to invasive species, provided key constraints (biosecurity, habitat area and long‐term viability) are addressed. Practical implication . This study delivers a user‐ready feasibility assessment tool that helps practitioners identify urban aquatic habitats suitable as refugia for threatened fish, provides methodological guidance for designing, implementing, and monitoring threatened‐fish translocations, and shows that where invasive‐species eradication is unfeasible, well‐managed urban refugia can complement or in some contexts, substitute for conventional in situ translocations.