Morocco′s aquatic biodiversity remains insufficiently studied, especially in terms of invertebrates, with numerous gaps persisting, even in protected areas. This study combines our research with existing studies to provide a comprehensive list that encompasses both old and new faunistic and distributional records of three orders of aquatic insects (Ephemeroptera, Plecoptera and Trichoptera) in Tazekka National Park, located in the Eastern Middle Atlas Mountains.

We provide an annotated list of 33 species, 23 of which were identified from 1400 specimens collected seasonally between the summer of 2018 and 2019 at 19 sampling sites. The remaining 10 species were identified from the literature sources and were not captured during this study. These 33 species belong to 31 genera and 21 families, comprising 9 species of Ephemeroptera, 14 species of Plecoptera, and 10 species of Trichoptera. The most interesting faunistic novelties consist of the capture of Epeorus cf. torrentium Eaton, 1881 (Ephemeroptera), Micrasema moestum Hagen, 1868 (Trichoptera), and Brachyptera auberti Consiglo, 1957, and Leuctra geniculata (Stephens, 1836) (Plecoptera), which are new records for the Middle Atlas.

Furthermore, this work provided the first data on the Ephemeroptera of the Tazekka National Park. Additionally, 9 species of Plecoptera and Trichoptera were newly captured in this park.

A chorological analysis revealed that most species are predominantly Mediterranean 61%, while those with a wider distribution occur in the Palearctic constitute the remaining 39%. In terms of endemism, 80% of the species recorded are endemic in the broad sense, with 44% classified as Ibero-Maghrebian, 31% endemic to the Maghreb, and 25% strictly Moroccan endemics.