Four new species of Acanthobothrium van Beneden, 1850 are described from guitarfish, Rhynchobatus cf. djiddensis (For- sskål), collected from the Gulf of Oman and Persian Gulf. Acanthobothrium janineae sp. n., a category 1 species, differs from all congeners in category 1 by having a long vagina extending into the vas deferens and different, proglottid and testis number except Acanthobothrium hypermekkolpos Fyler et Caira, 2010. Acanthobothrium fylerae sp. n., a category 1 species, can be differentiated by a combination of characters including the total length, proglottid and testis number, cirrus sac shape, and the length of the vagina and ovarian lobes. Both new species are similar to A. hypermekkolpos reported from Rhynchobatus laevis (Bloch et Schneider) from Australia in their scolex proper length, hook size and muscular pad, respectively. Acanthobothrium asrinae sp. n., a category 1 species, differs from other category 1 species by the shape of its hooks and the position of the tubercle at the mid-length of the axial prongs; in this respect it resembles A. bartonae Campbell et Beveridge, 2002 reported from Australia. Acanthobothrium jamesi sp. n. is among six category 1 species with post-ovarian testes. It differs from these species by total length, proglottid and testis number and the extension of the ovarian lobes. Although it is thought that R. djiddensis occurs in the region, the identities of the hosts of the newly described Acanthobothrium species await verification. There are two forms of host in the region and were designated as R. cf. djiddensis 1 and R. cf. djiddensis 2. More taxonomic work and the use of molecular techniques are needed to resolve the true identity of the host species.
