Redescription of Procyrnea uncinipenis (Molin, 1860) (Nematoda: Habronematidae) based on material from Rhea americana (L.) (Aves: Rheidae).

A detailed description of Procyrnea uncinipenis (Molin, 1860) (Habronematidae) is provided based on light- and scanning electron microscopy of newly collected material ex Rhea americana (L.) from a private conservation breeding park located in Cachoeiro de Itapemirim (State of Espírito Santo, Brazil). Of the four host specimens analysed, two were infected with P. uncinipenis; a total of 441 nematodes were collected in the proventriculus and gizzard. The specimens represented large nematodes, sexually dimorphic, with females larger than males, reddish in vivo, with two well developed lateral pseudolabia and two interlabia, one dorsal and one ventral, long oesophagus, divided into a muscular and glandular portion, didelphic ovaries, opisthodelphic uteri, two phasmids and a rounded chitinous structure near the caudal end. Males possess posterior extremity curved in spiral ventrally, with bilateral caudal alae and unequal in size and shape spicules. This study adds new morphological data, thus contributing to the knowledge on P. uncinipenis, a common parasite of R. americana.