Fish hosts, Galeocharax kneri (Steindachner, 1879), were netted in the Rio Grande, near Lavras, State of Minas Gerais, Brazil. They were taken on ice to the Department of Veterinary Medicine of the Universidade Federal de Lavras for examination. The isopod parasites were removed from the mouth of the hosts and fixed in 70% ethanol. The preserved specimens were sent to the Department of Zoology of the Universidade Federal do Paraná, Curitiba, for detailed studies. There, dissections of the mouthparts, pereopods, pleopods and uropods were examined after clearing in pure phenol to better visualize their morphology. Photographs were made with a digital camera which were used in making the drawings. Measurements are given in micrometers (µm) except where designated as millimeters (mm). TAXONOMYMaterial examined. Six females and seven males collected by the second author from the mouth of Galeocharax kneri caught in the Rio Grande near Lavras, Minas Gerais State, Brazil. The females measured 18-27 (23) mm long by 8-12 (10) mm wide and the males 17-28 (23) mm long by 8-12 (10) mm wide. Braga Schiödte & Meinert, 1881Diagnosis (from THATCHER 2002). Female: body about twice as long as wide, symmetrical. Cephalon not immersed in pereonite 1; frons obtuse, truncate or acute; antennal bases well separated. Pereonite 1 two to three times the length of 7; 5 and 6 shorter than 2-5; coxae compact, not extending posterior to respective pereonites. Pereopods relatively long with 7 th pair longer than others. Mandible subrectangular, lacking cutting process and incisor. Pleon slightly immersed in pereonite 7; pleonites usually produced laterally; pleopods multilaminate; 1 bilaminate, 2 quadrilaminate and 3-5 trilaminate. Pleotelson shield-like not keeled; uropods short with endopod shorter than exopod. Braga cigarra

Five new species of Monogenoidea (Dactylogyridae: Ancyrocephalinae) are described from the gills of freshwater fishes of South America: Jainus amazonensis sp. n., Tereancistrum kerri gen. et sp. n., and Trlnibaculum braziliensis gen. et sp. n. (all) from Brycon melanopterus (Cope), Januacá Lake near Manaus, Amazonas, Brasil; Tereancistrum ornatus sp. n. from Prochilodus reticulatus Steindachner, Rio Cauca, Juanchito, Cali, Valle, Colombia; and T. parvus sp. n. from Leporinus fasciatus (Bloch), Amazon River Basin. Two new genera are proposed. Tereancistrum gen. n. is characterized by having spathulate acessory anchor sclerites associated with the ventral anchors. Trinibaculum gen. n. is proposed for species with a single ventral bar, two widely separated dorsal bars, a dextroventral vagina, confluent intestinal crura, and intercecal gonads.

Summary :A new camallanid nematode, Procamallanus dentatus sp. n. is described from the intestine of the characid fish, Bryconops alburnoides Kner, 1859 from the Uburu River, Amazonas State, Brazil. The parasite is characterized mainly by the structure of the buccal capsule : four to five spiral thickenings are present in the buccal capsule of females, while about 10 large, anteriorly directed and sharply pointed teeth are present in that of the males. This feature is used for creating a new subgenus, Denticamallanus subgen. n., with the type species P. (D.) dentatus sp. n. Other features characteristic of this species are the presence of very short (0.078-0.117 mm) spicules of equal length, 2 pairs of preanal and 3 pairs of postanal papillae and the absence of caudal alae in the male. The tail of the female is short and wide, with a small conical appendage. The ratio of the muscular and the glandular parts of the oesophagus is 1 : 1.5-1.7. A key to subgenera of the genus Procamallanus Baylis, 1923 is provided.

Riggia paranensis Szidat, 1948 is redescribed on the basis of 30 female and 2 male specimens collected from the pericardial cavities of the curimatid fish Cyphocarax (= Curimata) gilberti (Quoy & Gaimard). The fishes were caught in the Itabapoana River, State of Rio de Janeiro, southeastern Brazil. The presence of" dwarf" males, as reported by Szidat, was verified. The fusion of the pleonites and pleotelson in adult females was also confirmed. The generic diagnosis was emended to include details of the mouthparts and pleopod

Four species of Monogenoidea (Dactylogyridae) are reported from the gills of freshwater fishes from Amazonas, Brasil, as follows: Anacanthorus spatulatus sp. n. from Colossoma bidens (Spix) and C. macropomum (Cuvier), and A. elegans sp. n., A. spiralocirrus melanopterus (Cope). Additionally, the status of the subfamily Anacanthorinae is discussed, and the diagnosis of Anacanthorus is emended.