This study evaluated the ectoparasite distribution on the gill archs of pond-reared pacu (Piaractus mesopotamicusHolmberg, 1887), hybrid patinga (P. mesopotamicusfemale x P. brachypomus(Cuvier, 1817) male), hybrid tambacu (Colossoma macropomum(Cuvier, 1816) female x P. mesopotamicus male) and hybrid surubim (Pseudoplatystoma reticulatumfemale x P. corruscansSpix & Agassiz, 1829 male). Atotal of 300 fish were examined from fish farms in West-Central Brazil for parasitological assessment of the gill arches I, II, III and IV, from the outer to inner arch, respectively. Only the monogenean Mymarothecium boegeriCohen & Kohn, 2005 and Anacanthorus penilabiatusBoeger, Husak & Martins, 1995 from the hybrid patinga showed the greatest (p<0.05) mean intensities on the gill arch I when compared to gill arch IV. Microhabitat preference was not observed in the other fish examined. Cope...

This study reports the presence of Enterogyrus cichlidarum Paperna, 1963 (Monogenoidea: Ancyrocephalidae) in the stomach of Nile tilapia, Oreochromis niloticus Linnaeus, 1758, cultured in the State of Santa Catarina, Southern Brazil. A total of 98 fish originating from a fish pond culture in Joinville, South Brazil, were examined. The fish were collected in the winter of 2007, in the summer, autumn, winter and spring of 2008. After anesthetized and sacrificed in a benzocaine solution, their  stomachs were removed, bathed in 55°C water, fixed in 5% formalin for quantification and attainment of the prevalence rate, mean intensity, mean abundance and mounted in Hoyer's. Prevalence rate throughout the period was 94%. The greatest mean intensities occurred in August 2008 and November 2008, followed by July 2007, January and May 2008. The great majority of Monogenoidea are branchial and ...

There's still a lot of ongoing debate whether the correct taxonomical nomenclature should be Monogenea or Monogenoidea. In this current note it will be addressed as Monogenea, since it's the most traditional (Wheeler & Chisholm, 1995), and therefore most known nomenclature. But the authors would like to point that we support the use of Monogenoidea for its phylogenetic approach.

Few studies have been done to evaluate the monogenean microhabitat preference. This study evaluated the monogenean distribution among different gill arches of Nile tilapia Oreochromis niloticus and seasonality. A total of 89 fish were captured in a pond located in Chapecó, Santa Catarina, for parasitological analysis. After fish euthanasia, the gill arches were removed, separated from the most external to the most internal and named as I, II, III and IV. Transparency, pH, oxygen, temperature, alkalinity, conductivity, ammonia, iron, orthophosphate, sulfide, nitrite and nitrate of water pond were measured. In spring 2008 the mean abundances of the monogeneans (Scutogyrus longicornis, Cychlidogyrus sclerosus, C. thurstonae and C. tilapiae) in the arches I, II, III and IV were, respectively, 11.45, 14.45, 13.8, 13.15, in summer 2008 theywere 13.12, 12.25, 14.94, 21.53, in summer 2009 they ...

Farmed fingerlings of South American catfish are frequently exposed to several parasites, but little information is available for implementing health programs for control and prevention of parasitic diseases in the hatcheries. This study evaluated the parasitic fauna of cachara catfish fingerlings (Pseudoplatystoma reticulatum Eingenmann & Eigenmann, 1889) and the hostparasite relationship during the early stages of rearing. A total of 302 cachara fingerlings were used for parasitic diagnosis and histopathological analysis. Ichthyophthirius multifiliis and Trichodina heterodentata were diagnosed as the most prevalent parasites, followed by Cryptobia sp., Henneguya sp., Monogenea and Nematoda. There was a positive correlation between the size of the fish and the mean intensity of parasitism by I. multifiliis. Proliferation of mucus cells, club cells, multifocal area of degeneration, e...