2026/06/08 by Bruna S. Santos, Luis M. da Costa, Maria Judite Alves +1 · 1 voice
Environmental Science · #Amphibian and Reptile Biology #Fish Ecology and Management Studies #Species Distribution and Climate Change
paper · doi:10.3897/nhcm.3.186661
openalex publication_date 2026/06/08 · openalex created_date 2026/06/09 · openalex updated_date 2026/07/22
Freshwater fish are amongst the most threatened species globally, a situation that is particularly acute in the Iberian Peninsula and Portugal. Natural History Collections (NHCs) are biodiversity data sources with unparalleled taxonomic, geographic and temporal scope. These collections are essential for modern scientific research and the conservation of species; however, the accession of voucher specimens has faced a steep decline in the last decades. As part of an ongoing effort to review the Portuguese vertebrate collections in the national NHCs, freshwater fish data from major museums and some smaller collections have been gathered and analysed to assess the coverage and representation of the species known from Portuguese inland waters. Overall, the collections do not fully represent the country’s freshwater biodiversity, neither at a taxonomic, geographic or temporal level. Nearly 97% of the species are found in the national NHCs (64 out of 66), but close to 40% of taxa are represented by less than 50 specimens and nearly 70% from less than 50 lots. From a geographic standpoint, the collections cover less than 40% of Portuguese territory and one fifth of species has less than 10% of their known range represented in the assessed institutions. Additionally, 60% of native species are threatened with extinction, but they represent only one quarter of all extant specimens. We draw attention to the risks of incomplete coverage, especially when dealing with such sensitive ecosystems as freshwater.