“…Its type species, Spectatus spectatus, has been reported mainly from serrasalmid fishes (Serrasalmidae) and, less frequently, parasitizing fishes of the families Bryconidae, Doradidae and Pimelodidae, in the Paraná River basin in Brazil and Argentina (Travassos, 1923;Travassos and Kohn, 1965;Hamann, 1982aHamann, , 1982bMasi Palláres, 1990;Parra et al, 1997;Moravec, 1998;Santos et al, 2003;Campos et al, 2009). Despite its widespread occurrence, the morphology of S. spectatus is not sufficiently known which has generated problems to separate Spectatus from 2 other kathlaniid genera, Falcaustra Lane, 1915 andChabaudinema Díaz-Ungría, 1968 (see Baker, 1980).…”