First Record of the Duck Leech Theromyzon tessulatum (Hirudinea: Glossiphoniidae) in Morocco Reveals a Regionally Unique Genetic Lineage

Despite Morocco's location at the intersection of major biogeographic regions and its rich variety of ecosystems, the diversity and distribution of its leech fauna are still insufficiently studied. Recent field surveys in northern Morocco have led to the discovery of the duck leech Theromyzon tessulatum (O. F. Müller, 1774), providing the first evidence of its occurrence in the country and an additional record for North Africa. This finding is supported by both morphological data and COI DNA barcoding, which revealed a unique haplotype in Morocco. Further faunistic and hydrobiological studies could result in the discovery of the species elsewhere in Morocco and North Africa.