Mawsonascaris parva sp. nov. (Nematoda: Ascaridida) from the Arabian whipray Himantura randalli Last, Manjaji-Matsumoto et Moore (Rajiformes: Dasyatidae) off the coast of Iraq.

Mawsonascaris parva sp. nov. collected from the Arabian whipray Himantura randalli Last, Manjaji-Matsumoto et Moore (Rajiformes: Dasyatidae) off the coast of Iraq is described and illustrated using light and scanning electron microscopy. The new species differs from its congeners by its small body size (8.11-18.2 mm long), the absence of an intestinal caecum, the slightly unequal spicules (left and right spicule 1.08-2.50 mm and 0.98-2.01 mm long, respectively, representing 12.1-13.7% and 10.1-12.1% of body length), the number and arrangement of male caudal papillae (13-14 pairs in total, arranged as: 7-8 pairs of precloacal, 1 pair of double paracloacal and 5 pairs of postcloacal) and the presence of a single, median precloacal papilla. Thus, a total of six species of Mawsonascaris are now known and this is the first species of this genus recorded from species of Himantura.