A new species of genus Hysterothylacium Ward et Magath, 1917 (Nematoda, Anisakidae) from Liparis tanakae (Scorpaeniformes, Liparidae) from the Yellow Sea, China

A new anisakid nematode, Hysterothylacium liparis sp. nov., is described from the intestine and stomach of the fish, Liparis tanakae (Gilbert et Burke, 1912) (Scorpaeniformes, Liparidae), a fish endemic to the Yellow Sea, China. The new species can be distinguished from the congeners by the absence of lateral alae, the length of the intestinal caecum (1.94-3.35 mm, 58.84-82.47% of oesophageal length), the number and arrangement of the caudal papillae (20-29 precloacal subventral pairs, 1 adcloacal pair and 4 postcloacal pairs), the size of the spicules (1.94-3.74 mm, 4.85-7.30% of body length) and the morphology of the tail tip. This is the first species of adult ascaridoid nematodes to be reported from fishes of the family Liparidae in northern China.