A new cestode species of the order Trypanorhyncha in Rhina ancylostoma (Elasmobranchii: Rhinopristiformes) from Persian Gulf

After sampling the cestodes from the Bowmouth guitarfish, Rhina ancylostoma Bloch & Schneider, 1801, in the Persian Gulf, a new cestode species of the order Trypanorhyncha was discovered and described. The new species possesses two bothria with free margins, prebulbar organs, gland cells within bulbs, a hetero-acanthous typical armature with hollow hooks and the tentacles with basal swelling and that the members of this species lack any prominent macrohooks on the basal part of the tentacles, the taxonomic placement of this new species is the genus Dollfusiella Campbell & Beveridge, 1994. In comparison with the congeners, Dollfusiella n. sp. shows the most affinity with D. vooremi (Sao Clemente & Gomes, 1989) based on the presence of more than 20 heteromorphous hooks in each principal row of the mid-metabasaltentacular armature, a testes number less than 100 in each proglottid, a basal armature with more than 10 rows of hooks and lacking a pars post bulbosa. Nonetheless, this new species can be easily differentiated from D. vooremi with having a very muscular vagina and a greater number of principal hooks on the metabasal region of the tentacles. The present study is the first report of the trypanorhynch fauna in the Bowmouth guitarfish, Rhina ancylostoma from the Persian Gulf. In order to sample the intact worms, the body cavity was opened and its contents were separated. Then the digestive system was opened longitudinally, placed into the plastic bag filled with 100% ethanol and transferred to the laboratory. In the laboratory, the cestodes were isolated from the tissue, placed in 70% ethanol, stained in acetic carmine, dehydrated in an alcohol series, cleared in methyl salicylate and mounted on slides in Canada balsam. Histological sections were prepared from some specimens with proglottid. The morphological examination was performed by optical microscopy.

کلیدواژه ها:

Cestode ، Trypanorhyncha ، Dollfusiella ، Persian Gulf