Cryptic diversity, characterized by morphologically similar but genetically distinct species, poses significant challenges to traditional taxonomic methods. Within monogeneans parasitizing northwest African barbels, this complexity hampers species identification, limiting our understanding of diversity, distribution and evolutionary relationships. Supported by previously published genetic data, we morphologically delineate herein 9 Gyrodactylus species from Morocco. Newly described species include G. agnesei sp. nov. and G. benhoussai sp. nov. from Luciobarbus rabatensis, with the latter also found on Carasobarbus fritschii, and both G. deburonae sp. nov. and G. marruecosi sp. nov. from L. massaensis. Additionally, G. diakini sp. nov. and G. louiziae sp. nov. were identified from L. rifensis and L. yahyaouii, respectively. Pterocapoeta maroccana harboured G. pterocapoetai sp. nov., morphologically resembling G. shigoleyae sp. nov. from sympatric L. zayanensis. We also examined taxonomical discrepancies between Gyrodactylus species from L. ksibi and L. pallaryi, evaluated the status of previously described G. nyingiae and described G. qninbai sp. nov. from L. ksibi. Our findings highlight the conservative morphology in northwest African Gyrodactylus, characterized by an ancestral median ridge in the ventral bar membrane, similar to that found in species from Eurasia. Subtle phenotypic features, like bifurcations in dorsal bars and proportions of marginal hooks, serve as diagnostic traits. We further evidenced a potential host-switching event from northwest African to Iberian hosts, correlating with the region's geological history and cyprinid dispersal events during intermittent closures of the Strait of Gibraltar. These insights illuminate the complex evolutionary processes driving gyrodactylid diversification in the West Mediterranean.

• Klíčová slova
• Morocco, Southwest Mediterranean, cyprinids, gyrodactylids, monogenea,
• MeSH
• Cyprinidae * parazitologie   MeSH
• fylogeneze MeSH
• infekce červy třídy Trematoda * veterinární   parazitologie   epidemiologie   MeSH
• nemoci ryb * parazitologie   epidemiologie   MeSH
• Trematoda * klasifikace   anatomie a histologie   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Maroko epidemiologie   MeSH

Monogenea (Platyhelminthes), mainly gill and fin ectoparasites of fish, are often recognized as host specific and morphologically and ecologically diverse. These parasites exhibit high species diversity at the level of host species or individual fish specimens. Using case studies, especially those widely performed in Dactylogyrus parasitizing cyprinoid fish, this article presents current knowledge on the ecology and evolution of congeneric gill monogeneans. The important aspects of the ecology of congeneric monogeneans are highlighted, in particular: host specificity expressed at several host levels (from strict specificity to phylogenetic specificity), microhabitat specificity expressed by restricted positions on fish gills to facilitate intraspecific mating, and the link between microhabitat preference and morphological adaptation (i.e., sclerotized structures of the haptor) or reproductive isolation. From the evolutionary perspective, this study focused on the processes of the speciation and diversification of congeneric monogeneans, highlighting the role of host switch as the most prominent coevolutionary event, accompanied in some cases mostly by intrahost speciation or cospeciation, as revealed by cophylogenetic studies. Here, important knowledge on evolutionary patterns of host specificity, microhabitat specificity, and morphological adaptation is presented. Host-specific monogeneans may represent an important tool for studying the historical biogeography of their hosts. Specifically, in the case of freshwater fish hosts exhibiting disjunctive distribution, they reflect both historical and contemporary contacts. The role of host-specific congeneric monogeneans in revealing historical intercontinental and intracontinental contacts between freshwater fish is highlighted. Finally, the importance of the role of genetic coadaptation, limiting the presence of host-specific monogeneans in hybrid fish, is emphasized.

TITLE: Monogènes spécifiques à leur hôte parasitant les poissons d’eau douce : écologie et évolution des associations hôtes-parasites. ABSTRACT: Les Monogènes (Plathelminthes), principalement ectoparasites des branchies et des nageoires des poissons, sont souvent reconnus comme spécifiques à leur hôte et diversifiés morphologiquement et écologiquement. Ces parasites présentent une grande diversité d’espèces au niveau des espèces hôtes ou des spécimens individuels de poissons. À l’aide d’études de cas (en particulier celles largement réalisées chez les Dactylogyrus parasitant les poissons cyprinoïdes), les connaissances actuelles sur l’écologie et l’évolution des monogènes branchiaux congénères sont présentées. Les aspects importants de l’écologie des monogènes congénères sont mis en évidence, en particulier la spécificité à l’hôte exprimée à plusieurs niveaux de l’hôte (de la spécificité stricte à la spécificité phylogénétique), la spécificité du microhabitat exprimée par des positions restreintes sur les branchies des poissons pour faciliter l’accouplement intraspécifique, et le lien entre la préférence du microhabitat et l’adaptation morphologique (c’est-à-dire les structures sclérifiées du hapteur) ou l’isolement reproductif. Du point de vue évolutif, l’étude a été concentrée sur les processus de spéciation et de diversification des monogènes congénères, soulignant le rôle du changement d’hôte comme l’événement coévolutif le plus important, accompagné surtout dans certains cas de spéciation ou de cospéciation intra-hôte, comme le révèlent les études cophylogénétiques. Des connaissances importantes sont présentées ici sur les modèles évolutifs de spécificité d’hôte, de spécificité de microhabitat et d’adaptation morphologique. Les monogènes spécifiques à l’hôte peuvent représenter un outil important pour étudier la biogéographie historique de leurs hôtes. Plus précisément, dans le cas des poissons d’eau douce hôtes présentant une distribution disjonctive, ils reflètent à la fois des contacts historiques et contemporains. Le rôle des monogènes congénères spécifiques à leur hôte dans la révélation des contacts intercontinentaux et intracontinentaux historiques entre poissons d’eau douce est mis en évidence. Enfin, l’importance du rôle de la coadaptation génétique limitant la présence de monogènes spécifiques à l’hôte chez les poissons hybrides est soulignée.

• Klíčová slova
• Fish parasites, Genetic coadaptation, Host specificity, Host-parasite coevolution, Monogeneans, Species coexistence,
• MeSH
• biologická evoluce * MeSH
• druhová specificita MeSH
• ekosystém MeSH
• fylogeneze MeSH
• hostitelská specificita * MeSH
• infekce červy třídy Trematoda veterinární   parazitologie   MeSH
• interakce hostitele a parazita * MeSH
• nemoci ryb * parazitologie   MeSH
• ploštěnci fyziologie   klasifikace   genetika   izolace a purifikace   MeSH
• ryby parazitologie   MeSH
• sladká voda * parazitologie   MeSH
• Trematoda fyziologie   klasifikace   genetika   MeSH
• žábry * parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The freshwaters of Iraq harbour a high diversity of endemic and phylogenetically unique species. One of the most diversified fish groups in this region is cyprinoids, and although their distribution is relatively well known, their monogenean parasites have only rarely been investigated. Herein, we applied an integrative approach, combining morphology with molecular data, to assess the diversity and phylogeny of cyprinoid-associated monogenean parasites. A total of 33 monogenean species were collected and identified from 13 endemic cyprinoid species. The highest species diversity was recorded for Dactylogyrus (Dactylogyridae, 16 species) and Gyrodactylus (Gyrodactylidae, 12 species). Four species of Dactylogyrus and 12 species of Gyrodactylus were identified as new to science and described. Two other genera, Dogielius (Dactylogyridae) and Paradiplozoon (Diplozoidae), were represented only by 4 and 1 species, respectively. Phylogenetic analyses of the Dactylogyrus and Gyrodactylus species revealed that the local congeners do not form a monophyletic group and are phylogenetically closely related to species from other regions (i.e. Europe, North Africa and Eastern Asia). These findings support the assumption that the Middle East served as an important historical crossroads for the interchange of fauna between these 3 geographic regions.

• Klíčová slova
• Cyprinoidei, Dactylogyrus, Dogielius, Gyrodactylus, Middle East, Paradiplozoon, phylogeny, species diversity,
• MeSH
• fylogeneze MeSH
• ryby MeSH
• Trematoda * genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Irák epidemiologie   MeSH
• severní Afrika MeSH
• Střední východ MeSH

The stunning diversity of cichlid fishes has greatly enhanced our understanding of speciation and radiation. Little is known about the evolution of cichlid parasites. Parasites are abundant components of biodiversity, whose diversity typically exceeds that of their hosts. In the first comprehensive phylogenetic parasitological analysis of a vertebrate radiation, we study monogenean parasites infecting tropheine cichlids from Lake Tanganyika. Monogeneans are flatworms usually infecting the body surface and gills of fishes. In contrast to many other parasites, they depend only on a single host species to complete their lifecycle. Our spatially comprehensive combined nuclear-mitochondrial DNA dataset of the parasites covering almost all tropheine host species (N = 18), reveals species-rich parasite assemblages and shows consistent host-specificity. Statistical comparisons of host and parasite phylogenies based on distance and topology-based tests demonstrate significant congruence and suggest that host-switching is rare. Molecular rate evaluation indicates that species of Cichlidogyrus probably diverged synchronically with the initial radiation of the tropheines. They further diversified through within-host speciation into an overlooked species radiation. The unique life history and specialisation of certain parasite groups has profound evolutionary consequences. Hence, evolutionary parasitology adds a new dimension to the study of biodiversity hotspots like Lake Tanganyika.

• MeSH
• biodiverzita MeSH
• biologická evoluce * MeSH
• cichlidy genetika   parazitologie   MeSH
• fylogeneze MeSH
• interakce hostitele a parazita genetika   MeSH
• jezera MeSH
• ploštěnci genetika   MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH