Monogenean parasite species descriptions from Labeo spp. hosts in the Vaal Dam, South Africa

Specimens of Labeo capensis (n = 13) and Labeo umbratus (n = 26) from the Vaal Dam (South Africa) were collected and examined for gill and skin monogenean parasites. Three new Dactylogyrus and one new Dogielius species are described. Dactylogyrus iwani n.sp. (longer inner root on anchor and predominates on L. capensis) and D. larindae n.sp. (shorter inner root on anchor and predominates on L. umbratus) show similarities in male copulatory organ (MCO) and anchor structure with representatives of the D. pseudanchoratus group. Dactylogyrus nicolettae n.sp. differs completely with regard to anchor morphology (stout with a curved inner root and reduced outer root), yet MCO morphology (curved penis and simple accessory piece structure of similar shape and size) are similar in all three species described. Dogielius intorquens n.sp. was collected from both hosts. Two forms, corresponding to host species and differing in anchor and MCO size but not shape, are described. This brings the number of Dactylogyrus species described from African Labeo spp. to 29, with D. intorquens n.sp. constituting the 16th Dogielius species from African Labeo spp. hosts.Keywords: aquaculture, cyprinids, Dactylogyrus, Dogielius, fisheries management, new species