A new species of Alexandercestus Ruhnke and Workman, 2013 (Cestoda: Phyllobothriidea) from the sicklefin lemon shark, Negaprion acutidens (Elasmobranchii: Carcharhinidae), in the Gulf of Oman

AbstractA new species,Alexandercestus masoumehae n. sp., is described from the sicklefin lemon shark,Negaprion acutidens (R üppell), from the Iranian coast of the Gulf of Oman. The new species is the third in this genus, all parasitizing species ofNegaprion Whitley. Based on morphological characters and scanning electron microscopy the new species is different from its congeners of in a combination of characters including total length, terminal proglottid length, cirrus sac length, and genital pore position. Compared toAlexandercestus gibsoni Ruhnke& Workman, 2013 andA. manteri Ruhnke& Workman, 2013 the specimens of the new species are smaller (7.08 –8.5 mm), with a smaller terminal proglottid length to width ratio (1:0.7–1.3 vs. 1.4–3.2:1 and 1.2–3.1:1, respectively), and have a more anterior genital pore (70–73% of proglottid length vs. 42–66% and 41–65%, respectively). In addition,A. masoumehae possesses less foliose bothridia compared withA. gibsoni, and more densely packed vitelline follicles in comparison withA. manteri. The SEM examination of the scolex in the new species reveals a specific pattern of microtriches adding new details in our understanding of the surface morphology of members ofAlexandercestus. Finally, the new species increases the total number of described tapeworm species fromN. acutidens to five and the described tapeworms in the Persian Gulf and Gulf of Oman region to 65.
Source: Journal of Parasitic Diseases - Category: Parasitology Source Type: research