Three new species of Anthobothrium van Beneden, 1850 (Cestoda: "Tetraphyllidea") from the grey sharpnose shark Rhizoprionodon oligolinx Springer, 1964 (Carcharhinidae) in the Persian Gulf.

The sampling of 22 specimens of Rhizoprionodon oligolinx Springer from the Persian Gulf made possible the description of three new species of Anthobothrium van Beneden, 1850. Anthobothrium parimae sp. nov. is different from its congeners, except for A. altavelae Neifar, Euzet and Ben Hassine, 2002, A. lyndoni Ruhnke and Caira, 2009, and A. lesteri Williams, Burt and Caira, 2004, in the total length. It differs from A. altavelae in the number of the proglottids; from A. lyndoni in the length of the mature proglottids; and from A. lesteri Williams, Burt and Caira, 2004 in possessing one hemicircular band, rather than two circular bands, of musculature in its bothridia. The other two new species, being the smallest in size within the genus, most closely resemble each other but differ in the position of the genital pore in the proglottid, the number of post-vaginal testes, the number of the ventral and dorsal columns of vitelline follicles in each lateral band, and the distribution of the gladiate spinitriches on the strobila. These three new species are the only "tetraphyllidean" species reported to date from the southern waters of Iran. In addition, for the first time, more than two congeners belonging to Anthobothrium are reported from the same host species sympatrically and simultaneously. The morphological variation within this genus is also discussed.