Two new species of Rhinebothrium (Cestoda: Rhinebothriidea) from granulated guitarfish Glaucostegus granulatus in the Gulf of Oman.

During a study of the rhinebothriideans of rays in the Gulf of Oman, two new species of Rhinebothrium Linton, 1890, Rhinebothrium kruppi sp. n. and R. persicum sp. n., were identified in Glaucostegus granulatus (Cuvier). Some significant features that distinguish R. kruppi sp. n. from R. persicum sp. n. include: scolex characteristics (hinged with 42-46 loculi vs. fusiform with 68-62 loculi), number of testes (4-5 vs. 20-27), genital pore position (61.1-76.9% of proglottid length vs. 47.2-63.3%), ovarian morphology (lobulated vs. follicular), cirrus-sac expansion (past midline of proglottid vs. limited to poral side of proglottid), vas deferens configuration (spanning posteriorly to near ovarian isthmus vs. to the level of ovarian anterior margins) and details of microthrix morphology. In addition, a combination of the aforementioned characteristics can be used to distinguish these two new species from other valid species of Rhinebothrium. These are the first species of rhinebothriidean cestodes to be described systematically from the Gulf of Oman, Iran. The two new species reported here increase the number of valid species of Rhinebothrium to 43.