Diplozoidae are common monogenean ectoparasites of cyprinoid fish, with the genus Paradiplozoon being the most diversified. Despite recent studies on Diplozoidae from Europe, Africa and Asia, the diversity, distribution and phylogeny of this parasite group appears to be still underestimated in the Middle East. The objective of this study was to investigate the diversity, endemism and host specificity of diplozoids parasitizing cyprinoid fish from the Middle East, considering this region as an important historical interchange of fish fauna, and to elucidate the phylogenetic position of Middle Eastern Paradiplozoon species within Diplozoidae. Four Paradiplozoon species were collected from 48 out of 94 investigated cyprinoid species. Three known species, Paradiplozoon homoion, Paradiplozoon bliccae and Paradiplozoon bingolensis, were recorded on new cyprinoid host species, and a new species, Paradiplozoon koubkovae n. sp., was recorded on Luciobarbus capito and Capoeta capoeta from the Caspian Sea basin in Iran and Turkey. Paradiplozoon bliccae, exhibiting a wide host range in the Middle East, expressed both morphological and genetic intraspecific variabilities. The four Paradiplozoon species collected in the Middle East were placed in divergent clades, showing the rich evolutionary history of diplozoid parasites in the Middle East. Our study also revealed that two lineages of African diplozoids have a Middle Eastern origin. We stress the importance of applying an integrative approach combining morphological, ecological and molecular methods to reveal the real diversity of diplozoids.

• Keywords
• Cyprinoidei, evolutionary history, host specificity, parasite fauna, phylogeography,
• MeSH
• Biological Evolution MeSH
• Cyprinidae * MeSH
• Phylogeny MeSH
• Trematoda * genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Turkey epidemiology   MeSH

The Diplozoidae are monogenean parasites of mainly cyprinoid fishes with a unique life cycle, whereby two larvae undergo anastomosis and fuse into a single cross-shaped specimen. Paradiplozoon is the most species rich and widespread genus of the family, with a distribution range covering Eurasia and Africa; however, some areas remain underexplored and their diplozoid fauna is uncertain. In the present study, the Paradiplozoon diversity was investigated in the peri-Mediterranean region, which has the highest levels of cyprinoid diversity and endemism in Europe. A total of 36 endemic cyprinoid species were sampled from sites in north-west Africa and the southern European peninsulas and investigated for the presence of diplozoid parasites. Of five Paradiplozoon species collected, three were identified as new to science: Paradiplozoon moroccoensis n. sp. from the Moroccan endemic Luciobarbus lepineyi; Paradiplozoon ibericus n. sp. from Iberian endemic cyprinids and leuciscids and Paradiplozoon helleni n. sp. from the Greek endemic Scardinius acarnicus and Tropidophoxinellus hellenicus (descriptions provided herein). In addition, new host records for P. homoion and P. megan are presented, with the former being most prevalent in the investigated region. Phylogenetic analysis supported paraphyly of the genus Paradiplozoon, and suggests the need for a careful taxonomic re-evaluation of this genus. Furthermore, the results showed that endemic Paradiplozoon of the peri-Mediterranean do not form a monophyletic group, suggesting multiple origins of this parasite groups in different peri-Mediterranean regions.

• Keywords
• Africa, Cyprinoidei, Europe, Paradiplozoon, Phylogeny, Species diversity,
• MeSH
• Biodiversity MeSH
• Cyprinidae parasitology   MeSH
• Phylogeny * MeSH
• Trematode Infections parasitology   veterinary   MeSH
• Life Cycle Stages MeSH
• Trematoda classification   growth & development   isolation & purification   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Africa, Northern MeSH
• Mediterranean Region MeSH