This paper is conducted for identifying the parasite which collected during regular routine inspection for the hygienic condition and health status of fish in 2019 at the central fish market shops at Jubail city, Saudi Arabia. Samples from an orange spotted grouper (Epinephelus coioides) fish showed heavy black streaks between the muscle fibers that was considered unmarketable and rejected by the consumer after had been cut and prepared for sealing. The black discolorations were in the form of heavy diffused focal black spots or forming threads of variable sizes embedded in the entire whole-body musculature of the fish. These samples were subjected to parasitological and pathological evaluation. The parasitological examination of the affected muscular tissues revealed infection by Huffmanela spp. eggs. The parasitic infection was identified on the bases of the morphological and ultra-structural characters of the eggs. The examination of the affected fish showed multifocal black parasitic remnants between the muscle fibers. The parasitic fragments were distributed all over the fish flesh either superficially in subcutaneous area or deep inside the muscular tissue and they have been concentrated in the flesh around the vertebral column. In conclusion; this case report confirmed the occurrence of Huffmanela spp. infection in the muscles of Epinephelus coioides by using light and scanning electron microscopy. Further molecular assessment is recommended.