Abstract
Groupers are large predators in the Serranidae family that feed on fish and small invertebrates. Identification of parasitic taxa of groupers was done concerning their morphological and biological characteristics. A total of 30 Cephalopholis sonnerati (Serranidae) specimens were investigated for digenetic trematodes in the Red Sea, Saudi Arabia. Only one bivesiculid species, belonging to the Bivesiculidae family, has been identified, with a prevalence rate of 60% (18/30) among infected fish. The Bivesicula species obtained from the fish host’s intestine is morphologically and morphometric compatible with Bivesicula claviformis, which was previously identified from Epinephelus fasciatus (Serranidae) in North Borneo. In addition, maximum parsimony based on Tamura-Nei model was utilized to determine the phylogeny of the recovered Bivesicula species using partial small subunit ribosomal RNA gene (18S rRNA) and large subunit ribosomal RNA gene (28S rRNA) sequences. The query sequences showed the identities of 99.39% and 94.02% for 18S (AJ287485.1) and 28S rRNA (AY222182.1) of the previously described Bivesicula claviformis, respectively. The present study demonstrated that Bivesicula claviformis is the first reported of this genus as endoparasites from C. sonnerati, as well as providing novel DNA data for this species.