Phyllodistomum conostomum (Olsson, 1876) (Digenea, Gorgoderidae): a Junior Subjective Synonym for P. umblae (Fabricius, 1780)

Specimens of Phyllodistomum conostomum from the type host, whitefish Coregonus lavaretus, in the type locality, Lake Storsjön, Sweden, are studied using light (LM) and scanning electron (SEM) microscopy. Comparisons are made with earlier descriptions. Specimens of Phyllodistomum from whitefish in Lake Tokke, Norway, are also studied using LM and SEM and found to be conspecific with P. umblae from the type host, arctic char Salvelinus alpinus, in the same locality. The types, position, arrangement and numbers of papillae are described for the specimens recovered from whitefishes. Since no significant morphological or size differences are found between specimens of P. umblae and P. conostomum from Norwegian and Swedish salmonids, P. conostomum is considered conspecific with and a synonym for P. umblae.