Necropsy on 15 specimens of white-tufted grebe, Rollandiarolland, caught in the Mar Chiquita and Chascomús lagoons (Buenos Aires province), revealed the presence of Contracaecumovale (Linstow, 1907). This nematode shows a marked specificity for podicipediform birds. The specimens were identified from morphological study on features such as cephalic and esophageal structures and caudal papillae, using both optical and scanning electron microscopy. This is the first record of C. ovale parasitizing R. rolland in Argentina.
Contracaecum ovale; Nematoda; Rollandia rolland; Podicipedidae
