Two new species of Dactylogyridae (Platyhelminthes: Monopisthocotyla) parasitizing Astyanax taeniatus (Characiformes: Characidae) from the Fiocruz Mata Atlântica Biological Station, Rio de Janeiro, Brazil

During a parasitological survey of the Engenho Novo River at the Fiocruz Mata Atlântica Biological Station, Fiocruz Mata Atlântica Campus, Rio de Janeiro, Brazil, two new species of Dactylogyridae were found from the gill lamellae of the characid fish Astyanax taeniatus (Jenyns), known as “lambari”. Diaphorocleidus santosclappae sp. nov. differs from all its congeners mainly by the morphology of its accessory piece, which consists of a rod-like structure bearing a lateral projection at its proximal end and a cap-like structure distally.

Jainus mataatlanticaensis sp. nov. differs from previously described species in the pear-shaped accessory piece composed of thin, bilaterally sclerotized margins connected by a delicate membranous wall. This study represents the first helminthological survey of fishes inhabiting the Engenho Novo River and expands the current knowledge of the helminth fauna of freshwater fishes from Rio de Janeiro. With the addition of the new taxa, the numbers of valid species in Diaphorocleidus and Jainus increase to 19 and 15, respectively.