Four new species of Acanthobothrium van Beneden, 1850 are described from guitarfish, Rhynchobatus cf. djiddensis (Forsskål), 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., Loghman Maleki, Masoumeh Malek, Harry W. Palm., and Obsahuje bibliografii
Two new species of Acanthobothrium van Beneden, 1850 from the spiral intestine of Pastinachus cf. sephen Forsskål from the Iranian coast of the Persian Gulf and the Gulf of Oman are described. To analyse the surface ultrastructure the worms were studied using light and scanning electron microscopy. Acanthobothrium jalalii sp. n. belongs to the category 1 species of the genus so far including 43 species. This tiny new species differs from the other category 1 species by its small total length (2.18 ± 0.49 mm), number of proglottids (4.7 ± 0.9) and testes (24 ± 3), terminal segments in an apolytic condition and the shape of the cirrus-sac. Acanthobothrium sphaera sp. n. is a small worm that belongs to the category 2 species of the genus so far including 36 species. A. sphaera sp. n. differs from the other category 2 species by its small total length (1.6 ± 0.2 mm), number of proglottids (9.6 ± 1.2) and testes (12 ± 1), the presence of a vaginal sphincter and the shape of the ovary. This is the first report of Acanthobothrium from the cowtail stingray, P. cf. sephen, from the Persian Gulf and Gulf of Oman. Pastinachus sephen sensu lato has been reported as a common host of species of Acanthobothrium. Most recently, the host genus Pastinachus Rüppell has been split into five nominal species and several Acanthobothrium species infect the newly described congeners but not P. sephen. The real identity of the host studied within the present study is still in question, since sequence data of three specimens from the Gulf of Oman do not correspond to P. sephen sensu stricto.