Two new species of Paraorygmatobothrium Ruhnke, 1994 (Tetraphyllidea: Phyllobothriidae) from the smooth-hound Mustelus mustelus (L.) and the gummy shark M. antarcticus Günther (Carcharhiniformes: Triakidae)

Two new tetraphyllidean species, Paraorygmatobothrium bai n. sp. and P. rodmani n. sp., are described from the smooth-hound shark Mustelus mustelus (Linnaeus) and the gummy shark M.s antarcticus Günther , respectively. The two species are generally consistent in morphology with the nine existing species of Paraorygmatobothrium Ruhnke, 1994. P. bai n. sp. and P. rodmani n. sp. differ from the existing species of Paraorygmatobothrium in exhibiting gravid proglottids on the strobila. P. bai n. sp. differs from P. rodmani n. sp. in testicular shape and number, in addition to significant differences in body length, and terminal and subterminal proglottis length to width ratios. Description of these two new species increases the known number of species of Paraorygmatobothrium to 11.