Redescription of Zeuxapta seriolae (Meserve, 1938) and Zeuxapta australica Lebedev, 1968 (Monogenea: Heteraxinidae).

Redescription is given of heteraxinid monogeneans Zeuxapta seriolae (Meserve, 1938), type species of the genus, and Zeuxapta australica Lebedev, 1968 (formerly Z. seriolae australica). Type specimens of Z. seriolae from Seriola dorsalis from Galápagos Islands were differentiated from Z. australica specimens collected by Lebedev from Seriola glandis (now Seriola lalandi) from Tasman Sea, the type locality, by the shape of the vagina, which consisted of the transversely oval central body and horizontally extended paired tubes in the former, and the transversely oval central body and short, obliquely posteriad paired extensions in the latter. Zeuxapta japonica (Yamaguti, 1940) and Zeuxapta kahala (Yamaguti, 1968) were synonymized with Z. seriolae. Hitherto undescribed Zeuxapta specimens were also examined; those from Seriola aureovittata from Japan and China, and specimens from Seriola dumerili from Japan and Spain were identified as Z. seriolae, while those from Seriola lalandi from Chile and New Zealand were identified as Z. australica. Specimens from S. lalandi (as Seriola glandis) from Heron Island, Australia described by Rohde in 1978 as Z. seriolae consisted of Z. seriolae and Z. australica.