Recent research in various Moroccan areas allowed an update and a revision of the Moroccan Ephemeroptera checklist. In this case, 54 species are now listed, belonging to 10 families and 26 genera. The distribution of all studied species is discussed, as well as their biogeographical affinities. Moroccan Mayflies are characterized by a clear dominance of Mediterranean elements with a strong rate of endemism (33.4%).

Baetis rifensissp. nov. is the first representative of the Baetis fuscatus group to be described from the Maghreb. It was collected from streams in the Rif region of northern Morocco. All species of the B. fuscatus group are morphologically very similar, with slight differences in colour. Thus, in addition to morphological description, species delimitation based on genetic evidence was carried out. The new species was compared with other members of the B. fuscatus group from the Palaearctic region.

We describe a new species of Prosopistoma collected in the High Atlas Mountains of Morocco. Prosopistoma maroccanumsp. nov. appears to be morphologically more similar to the European highly endangered P. pennigerum (Müller, 1785) than to the other Maghrebian species, P. alaini Bojkova & Soldán, 2015. A gene tree including the few available barcode sequences of Palearctic Prosopistoma specimens is provided. Possible affinities with West African species are also discussed.

In recent decades there has been a significant increase in the presence of plastics in the environment, particularly in the marine environment, due to its great applicability in all fields of life. The effects of chronic ingestion of contaminated microplastics are still unknown, but several studies suggest that there is a potential gateway to the trophic network, especially when these plastics support other pollutants harmful to human life and act as a vehicle of entry into the organisms, making them more bioavailable. For this reason, the present work aims to evaluate the adsorption capacity that microplastics have for different metals depending on the physicochemical conditions of the aquatic environments (exposure time, pH, salinity). To do this, two types of microplastics were selected (polypropylene and polyethylene), and a group of two essential metals (Cu, Zn) and two toxic ones (Cd, Pb) were evaluated. Virgin pellets of both, polyethylene and polypropylene, were able to adsorb metals (Cu, Cd, Pb, Zn) in the aquatic environment, although the adsorption was low in most of the cases. Only minor differences were found in the adsorption capacity of the two studied materials. The exposure time showed an important effect regarding the adsorption capabilities of pellets, showing different adsorption rates for different metals. However, all studied metals showed the same behaviour in relation to pH and salinity, increasing the adsorption percentages as pH increase, and decreasing the adsorption percentages when salinity increase for lower salinities.