Parasitism by Monogenoidea in Piaractus mesopotamicus (Characiformes, Characidae) cultivated in Paraná River (Brazil).
This study investigated the occurrence, prevalence, mean abundance and mean intensity of monogenoidean parasites in Piaractus mesopotamicus farmed in cages in the reservoir of the Itaipu Hydroelectric Power Station, Paraná River, Brazil. The parasite distribution pattern and the correlation of prevalence and abundance with the total length of hosts were also investigated. Four monogenoidean species were collected: Anacanthorus penilabiatus, A. toledoensis, Mymarothecium ianwhitingtoni and M. viatorum. All the parasites collected in P. mesopotamicus showed the typical aggregated distribution pattern, and the abundance and the prevalence did not shown any correlation with the total length of hosts.
Anacanthorus toledoensis n. sp. and Mymarothecium ianwhittingtoni n. sp. (Dactylogyridae: Monogenoidea) Parasitizing Cage-Reared Piaractus mesopotamicus (Characiformes, Characidae) in the State of Paraná, Brazil
ABSTRACT:  Two new species of Dactylogyridae (Monogenoidea) found parasitizing the gills of the pacu, Piaractus mesopotamicus (Holmberg, 1887), are described: Anacanthorus toledoensis n. sp. and Mymarothecium ianwhittingtoni n. sp. These monogenoideans were collected in the gills of all 38 pacus reared in cages in Toledo, State of Paraná, Brazil. Anacanthorus toledoensis n. sp. is characterized by the slightly sigmoid male copulatory organ (MCO) with a membranous flap along the longitudinal axis, which ends at the distal, spatulated portion of the organ, and by the rod-shaped accessory piece bearing a protruding median projection. Mymarothecium ianwhittingtoni n. sp. differs from all other species of the genus by the morphology of the anchors and by the structure of the copulatory complex comprising an arcuate MCO, with basal flap and accessory piece with a distal rod, somewhat sigmoid, and subterminal flap hooked.
Helminths parasites of freshwater fishes from Pirassununga, SP, Brazil
Twelve species of parasitic helminths, seven trematodes, four nematodes and one acanthocephalan are reported from various hosts. Creptotrema lynchi, a parasite from Bufo marinus in Colombia, is described for the first time in fish and from Brazil, parasitizing two different species. A list of the host species, measurements and figures of most parasites are included with particular reference to the tegument of Bellumcorpus major recovered from a new host. The genus Zonocotyloides Padilha, 1978 is considered a synonym of Zonocotyle and the new combination: Zonocotyle haroltravassosi is proposed to the species Zonocotyloides haroltravassosi Padilha, 1978. The nematodes Cucullanus pinnai and Procamallanus (Spirocamallanus) inopinatus and the trematode Pararhipidocotyle jeffersoni are reported in new hosts. The description of the acanthocephalan Neoechinorhynchus curemais (new locality record) is supplemented. Other parasites recovered include the nematodes Travnema travnema (new locality record), Rondonia rondoni and the digenetic trematodes Cladocystis intestinalis, Pseudosellacotyla lutzi (new locality record), Teratotrema sp. and Zonocotyle bicaecata.