Rudolphiella szidati sp n. (Proteocephalidea : Monticelliidae, Rudolphiellinae) parasite of Luciopimelodus pati (Valenciennes, 1840) (Pisces : Pimelodidae) from Argentina with new observations on Rudolphiella lobosa (Riggenbach, 1895)

Rudolphiella szidati sp. n. (Cestoda, Monticelliidae, Rudolphiellinae) is d escribed from the anterior intestine of the pimelodid fish, Luciopimelodus pati caught in Parana river and de la Plata river (Argentina). Additional i nformations to the description of the type material of Rudolphiella lobosa (type species of the genus) is given. R. lobosa was not found in L. pati (a s reported originally by Riggenbach, 1895) and has never been found since i ts original description. The new species differs from other species of Rudo lphiella by its larger scolex, a higher number of testes and by its distinc t egg shape. A diagnosis of Rudolphiella is given. The following taxonomica l actions are introduced: Rudolphiella piracatinga (Woodland, 1935) comb. n ov. for Monticellia piracatinga Woodland, 1935; Monticellia rugata Rego, 19 75 syn. nov. of Rudolphiella piracatinga (Woodland, 1935). The presence of glandular cells within the scolex's apex is observed in all known Rudolphie lla species i.e. R. lobosa, R. myoides, R. szidati, R. piracatinga, R. pira nabu. Rudolphiella, the sole genus within Rudolphiellinae, is widespread in a monophyletic group of hosts (Calophysus-group sensu de Pinna, 1998) sugg esting likely coevolution.