Trypanorhynch cestodes of teleost fish from the Persian Gulf, Iran.

A total of 299 fish belonging to ten teleost species were studied in Iranian waters at the north-eastern coast of the Persian Gulf for larval trypanorhynch cestode infection. The following trypanorhynch species were identified: Callitetrarhynchus gracilis Pintner, 1931, Pseudogilquinia thomasi (Palm, 2000), Pterobothrium lesteri Campbell and Beveridge, 1996 and Pseudolacistorhynchus shipleyi (Southwell, 1929). The most abundant parasite was C. gracilis which was isolated from seven teleost species. The highest prevalence (62.9%) and dominance (0.98) were demonstrated for P. thomasi with a maximum intensity of 22 in Indian halibut Psettodes erumei. Collections of P. lesteri and P. shipleyi from the Persian Gulf represent new locality records, thus extending the known range of distribution for both species. Four new host records are established. The recorded combination of trypanorhynch species and the established host range correspond to other regions, such as off the Brazilian coast. In terms of species distribution, the north-western part of the Indian Ocean, together with the Gulf of Bengal and the Indonesian archipelago, share the same species, resulting from connected water bodies. All trypanorhynch species were isolated from the body cavity, except for P. thomasi which was recorded from the musculature of P. erumei. Relatively high intensities of infection in P. erumei may be of public health concern in the region, necessitating the consumption of well-cooked fish products.

Two new species of Paraorygmatobothrium Ruhnke, 1994 (Cestoda: Tetraphyllidea) from the carcharhinid shark Carcharhinus cf. dussumieri (Müller & Henle) in the Persian Gulf.

New collections of tapeworms from the carcharhinid shark species Carcharhinus cf. dussumieri (Müller & Henle), the whitecheek shark, in the Persian Gulf have yielded two new species belonging to the tetraphyllidean genus Paraorygmatobothrium Ruhnke, 1994 (Phyllobothriidae). Both new species resemble the subset of Paraorygmatobothrium species that bear gongylate columnar spinitriches, rather than serrate gladiate spinitriches, on their distal bothridial surfaces. In combination, their shorter lengths, smaller number of testes and smaller bothridial apical suckers distinguish both Paraorygmatobothrium mobedii n. sp. and Paraorygmatobothrium sinuspersicense n. sp. from all but two of their congeners. They conspicuously differ from P. exiguum (Yamaguti, 1935), in that the spinitriches on their distal surfaces are not arranged on 'bumps' and from P. filiforme (Yamaguti, 1952) in their possession of fewer proglottids. The two new species differ from one another in cirrus-sac shape, testicular shape and arrangement, and vitelline follicle arrangement (i.e. 2 vs 4-6 follicles in each lateral band). In addition, statistically significant differences were seen in terminal proglottid length, ovarian length and apical sucker diameter. This brings the total number of species of Paraorygmatobothrium to 14, and extends the number of carcharhiniform host genera known to host members of the genus to seven. This is also the first description of tapeworms from an elasmobranch in the Persian Gulf.

Parasites as heavy metal bioindicators in the shark Carcharhinus dussumieri from the Persian Gulf.

In this study the lead and cadmium concentrations in the liver, intestine, muscle and gonad of the shark Carcharhinus dussumieri and its parasites, Anthobothrium sp. and Paraorigmatobothrium sp. (Cestoda), were measured and compared. Tissue samples were collected from Iranian coastal waters of the Persian Gulf. After tissue preparation, the cadmium and lead concentrations were analysed using the Inductively Coupled Plasma technique. The results revealed that lead and cadmium concentrations in both parasite species were many times higher than in the host tissues. The results strongly support the view that helminth parasites are extremely sensitive early warning bioindicators, particularly in sensitive environments under threat but where pollution levels are presently low. They may also have a beneficial effect on the health of their hosts by acting as heavy metal filters.