Changes in hematological and biochemical parameters of tambaqui (Colossoma macropomum ) parasitized by metazoan species.

The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.

Eggs hatching and oncomiracidia lifespan of Dawestrema cycloancistrium, a monogenean parasitic on Arapaima gigas.

Within the production chain of the Arapaima gigas (pirarucu), sanitary issues are still faced at the fingerling phase regarding infestations by the monogenean Dawestrema cycloancistrium. The present study had the objectives of describing the morphology and development phases of this parasite's eggs and oncomiracidia and determining the hatching time and lifespan of the oncomiracidia at different temperatures. D.

Myxobolus sp. (Myxozoa) in the circulating blood of Colossoma macropomum (Osteichthyes, Characidae).

Myxosporea parasitize many organs in fresh and saltwater fish. Species of the genus Myxobolus parasitizing the gills and other organs of the tambaqui Colossoma macropomum have been described. In the present study, blood smears were made from juvenile tambaqui and were stained with May Grunwald-Giemsa-Wright in order to identify myxozoan parasites.

Relationship between mercury concentrations in the blood with that in the muscle of four estuarine tropical fish species, Rio de Janeiro State, Brazil.

The aim of this work was to assess the relationship between mercury concentrations in the blood with that in muscle for non-invasive mercury contamination assessment in fish. At Ribeira Bay were collected 198 fishes of 4 species (Genidens genidens, Arius luniscutis, Haemulon steindachneri, Micropogonias furnieri). At Guanabara Bay were collected 84 fishes of 2 species (Genidens genidens, Micropogonias furnieri).