Aporocotylids from batoid and elopomorph fishes from Moreton Bay, Queensland, Australia, including a new genus and species of blood fluke infecting the Giant shovelnose ray, Glaucostegus typus (Rhinopristiformes: Glaucostegidae)

摘要

Fishes of the elasmobranch superorder Batoidea and the basal teleost superorder Elopomorpha were assessed for blood flukes (Digenea: Aporocotylidae) during a parasitological survey conducted in Moreton Bay, Queensland, Australia. A new blood fluke genus and species, Ogawaia glaucostegi n. gen., n. sp., is described from the Giant shovelnose ray, Glaucostegus typus (Anonymous [Bennett]) (Rhinopristiformes: Glaucostegidae). Ogawaia glaucostegi differs from species of all other aporocotylid genera in the combination of the absence of anterior caeca and oral sucker, having a pronounced distal oesophageal chamber, a strongly coiled testis and a common genital pore. The new species most closely resembles Myliobaticola richardheardi Bullard & Jensen, 2008, from which it differs in lacking an oral sucker and in possessing a straight (rather than coiled) oesophagus, longer caeca in proportion to the oesophageal and total body length, and a much longer testis relative to body length. Ogawaia glaucostegi is just the eighth aporocotylid described from chondrichthyans, of which four belong to monotypic genera. This is the first description of a blood fluke from the order Rhinopristiformes, and the first of a chondrichthyan-infecting aporocotylid from Australian waters. Elopicola bristowi Orelis-Ribeiro & Bullard, 2017 is reported from Australia for the first time, from the type-host, Elops hawaiensis Regan (Elopiformes: Elopidae). This species is identified by morphological and molecular data and distinctions between our specimens and those of the original description are discussed.