First Study on Gyrodactylus (Monogenea: Gyrodactylidae) in Morocco, with Description of a New Species from Luciobarbus pallaryi and Luciobarbus ksibi (Actinopterygii: Cyprinidae)

Abstract

To date, 41 species of Gyrodactylus have been described from Africa. However, none of these have been reported in Morocco. After identifying and examining 738 cyprinid host specimens, 26 specimens belonging to Gyrodactylus were found to parasitize the gills of nine species of Luciobarbus, Carasobarbus, and Pterocapoeta. The current study provides new information about the presence of a new parasitic species in Morocco, the first to be characterized on a species level in the Maghreb region. It describes in detail 12 specimens of Gyrodactylus isolated from the gills of Luciobarbus pallaryi (Pellegrin, 1919) and Luciobarbus ksibi (Boulenger, 1905). Based on morphoanatomical observations, the characterization of the specimens collected indicates a species of Gyrodactylus that is new to science, described here as Gyrodactylus nyingiae n. sp. The new species is different from previously described gyrodactylids infecting African cyprinid hosts because it has a longer hamulus total length, a longer hamulus root, a downward projecting toe of the marginal hook, and a trapezium-shaped ventral bar membrane with a slightly striated median portion and small rounded anterolateral processes. This study increases the total number of Gyrodactylus spp. found in African cyprinids to four.

Diversity and Phylogeny of Gyrodactylus spp. (Monogenea: Gyrodactylidae) across the Strait of Gibraltar: Parasite Speciation and Historical Biogeography of West Mediterranean Cyprinid Hosts

“…Conversely, the hamuli of G. moroccensis sp. nov. seem similar to those in the Gyrodactylus specimen from L. ksibi assigned by Shigoley et al [54] to G. nyingiae. The specimen included in [54], which was identified as G. nyingiae on L. ksibi, may thus be either G. moroccensis sp.…”

“…nov. seem similar to those in the Gyrodactylus specimen from L. ksibi assigned by Shigoley et al [54] to G. nyingiae. The specimen included in [54], which was identified as G. nyingiae on L. ksibi, may thus be either G. moroccensis sp. nov. or a so-far-undescribed species, but it definitely does not represent the same species as that found on L. pallaryi.…”

“…nov. (see above). It should be noted that, according to Shigoley et al [54], the inner roots of hamuli exhibited by the former described species, G. nyingiae from L. pallaryi, are not twisted. Conversely, the hamuli of G. moroccensis sp.…”

“…The accessory portion around the hamuli and the T-shape of the dorsal bar differentiate G. gibraltarensis sp. nov. from a single gyrodactylid species found on the opposite side of the Strait of Gibraltar (Maghreb), namely Gyrodactylus nyingiae Shigoley, Rahmouni, Louizi, Pariselle and Vanhove, 2023, described from Luciobarbus pallaryi Pellegrin, 1919 and L. ksibi [54]. The median ridge of the ventral bar and its long lateral processes are characters which seem to be restricted to some Gyrodactylus spp.…”

“…So far, these studies remain the only ones using gill-specific monogeneans to elucidate historical contacts between West Mediterranean ichthyofauna. Knowledge on the morphological diversity of gyrodactylids of Northwest African cyprinids [54] and from the Iberian Peninsula [55] remains largely insufficient. To our knowledge, the available literature on gyrodactylid species from Iberian cyprinids is outdated and apparently inaccurate [55], and no genetic data are available for Gyrodactylus spp.…”