<div>Background: Carangids, like any other fish, can become infected with a variety of external and internal parasites. Little information on parasite infestations in these fish species is known. This study aimed to provide light on parasites that infect caragnids in Saudi Arabia.&nbsp; 
 
Methods: A total of 20 Carangoides caeruleopinnatus specimens were collected from the Red Sea (Saudi Arabia) and then examined for the presence of digenetic trematodes. Parasitic species were isolated and studied morphologically by using light microscopic examination and molecularly via the partial sequencing of 18S rRNA and 28S rRNA genes.&nbsp; 
 
Result: Only one parasitic species has been identified. This parasite is morphologically and morphometric compatible with previously Monostephanostomum mesospinosum, identified from Carangoides malabaricus in VSK, BOB. Phylogeny revealed that these putative acanthocolpid species nested well within a clade clustering Monostephanostomum species, which along with morphological data, suggests it is a member of the genus Monostephanostomum. Query sequences showed identities of 97.99% and 97.98% for 18S (EF506762.1.1) and 28S rRNA (EF506763.1) of Monostephanostomum nolani, respectively. This study reflects the third account of this genus as endoparasitic taxa of various carangid fish, as well as providing novel DNA data for this species.</div>

Monostephanostomum mesospinosum (Digenea: Acanthocolpidae) Infecting the Coastal Trevally Carangoides caeruleopinnatus (Carangiformes: Carangidae) from the Marine Water off Saudi Arabia