Chalcinotrema thatcheri n. sp. (Digenea: Haploporidae) from Brazilian freshwater fishes, a redescription of C. ruedasueltensis Thatcher, 1978 and comments on the validity of the genus.

Chalcinotrema thatcheri n. sp. from the intestine of Schizodon knerii is described. It is most closely related in general morphology to C. salobrensis Freitas, 1947 and C. ruedasueltensis Thatcher, 1978, from which it differs, respectively, in: testis-size, the distribution of the vitelline follicles and the distance between the gonads; and body-size, egg-size, the extent of the caeca and the shape of the seminal vesicle. The holotype of C. ruedasueltensis is redescribed with original figures. Chalcinotrema Freitas, 1947, is considered a good genus distinct from Carassotrema Park, 1938, on the basis of the presence of uterine loops between the ovary and testis and its totally different geographical distribution. Carassotrema tilapiae Nasir & Gomez, 1976 is transferred to the former genus as Chalcinotrema tilapiae (Nasir & Gomez, 1976) n. comb.