Morphological and molecular analyses Protolamellodiscus senilobatus (Monogenea: Diplectanidae), a gill parasite infecting the soldier bream Argyrops filamentosus (Sparidae)

Abstract

Monopisthocotyleans belonging to the family Diplectanidae infect marine fish and are distinguished by a posterior complex haptor. The solider bream Argyrops filamentosus Valenciennes (Perciformes: Sparidae), is one such species that is under consideration caught from the Red Sea (Saudi Arabia). This study is the first description of a diplectanid species from the gills of the soldier bream fish, morphologically by light as well as by molecular analysis of the parasite partial 28S rRNA sequences through multiple alignments and phylogeny by maximum likelihood (ML) analysis which is provided for the first time for the described parasite species. Thirty soldier bream fish were collected from marine water off Saudi Arabia; gills were detached and further analyzed for parasitic infection. A monogenean parasite with a complicated haptor made up of two comparable lamellodiscs, three bilateral pairs of lobes, two pairs of anchors, three bars, and seven pairs of marginal hooks was discovered to naturally infect 21 samples of the examined fish. The molecular analysis of the parasite 28S rRNA and phylogeny revealed a percentage of identities 98.41–77.97 % for Diplectanidae species within a monophyletic clade of Dactylogyridea where a maximum percentage of 98.41 % were obtained for morphologically different sister taxon Lamellodiscus acanthopagri. The results of phylogeny are in line with those obtained through morphological classification, which showed that the parasite identified shared morphological characteristics with Protolamellodiscus senilobatus, a species that had not before been identified by DNA analysis. Under accession number OP419541.1, the obtained parasite sequences were added to the GenBank database.