Toxicity and effects of copper sulfate on parasitic control and hematological response of tambaqui Colossoma macropomum.

The purpose of this work was to determine the mean lethal concentration (LC50-96h) of copper sulfate (CuSO4) for juveniles Colossoma macropomum (Characidae), to evaluate the effectiveness of different concentrations of CuSO4 on elimination of parasites, as well as to study the effects of CuSO4 on blood parameters after short-term exposure. After determination of the LC50-96h from 17.5 mg L-1 of CuSO4, it was investigated the effects of exposure for 48 h to 1.75, 4.37 and 8.75 mg L-1 of CuSO4, on parasites and blood parameters. In gills and skin, concentrations of 4.37 and 8.75 mg L-1 of CuSO4 eliminated Monogenoidea Anacanthorus spathulatus. In fish exposed to different concentrations of CuSO4, plasma total protein, chloride, potassium, glucose and copper levels, hemoglobin and hematocrit were similar to controls, whereas sodium levels presented decrease in fish exposed to 1.75 and 4.37 mg L-1. Red blood cell counts decreased in fish exposed to different three concentrations of CuSO4, while the Mean Corpuscular Volume (MCV) increased. However, exposure to 8.75 mg L-1 of CuSO4 caused decrease on total leukocytes, lymphocytes, neutrophils and PAS-positive granular leukocytes (PAS-GL) number when compared to control fish

Weight-length relationship, condition factor and blood parameters of farmed Cichla temensis Humboldt, 1821 (Cichlidae) in central Amazon.

Farming of native carnivore fish species has drawn attention due to their promising use in aquaculture. Among these species, tucunaré of the genus Cichla stand out, them being of high economical interest for sport fishing and Amazon's industry of ornamental fish. The present study describes the weight-length relationship (WLR), relative condition factor (Kn), red blood cell parameters, thrombocytes and leukocytes count of Cichla temensis Humboldt, 1821, farmed in central Amazon. Fish that underwent food training during fingerling culture received extruded ration containing 45% of crude protein during fattening, and had Kn with values from 0.925-1.199, which indicated good health condition during the culture. The equation obtained from the WLR was W = 0.0073Lt3.1435, indicating an isometric growth, which is the desirable for fish of fish farm. Red blood cell counts, total thrombocyte and leukocyte counts, hematocrit, hemoglobin concentration, mean corpuscular volume (MCV), concentration of mean corpuscular hemoglobin (MCHC), lymphocytes, monocytes and neutrophils had intra-specific variation. A significant (p<0.001) positive correlation of the red blood cells number with the hemoglobin concentration and hematocrit was found. These are the first sets of blood parameters for C. temensis and could be used as reference for comparison in further studies to evaluate the health status of this fish in different environments, because assessment of these parameters may be used as quick tool for diagnosing diseases, stress and malnutrition

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. Out of a total of 36 fish examined, one specimen (2.7%) that was reared in a cage presented spores that were identified as M. colossomatis, whereas fish kept in 250 L tanks showed prevalence of 5.5%. This is the first report of M. colossomatis in the blood of farmed tambaqui in the Amazon region. These results indicate that myxozoan parasites should also be investigated in fish blood smears. Some myxosporean species may cause diseases in fish, and these species need to be identified so that adequate preventive sanitary control can be instituted

Parâmetros hematológicos do jacaré-tinga Caiman crocodilus crocodilus Linnaeus, 1758 (Crocodylia, Alligatoridae) da bacia do médio rio Negro, Amazonas, Brasil.

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Antiparasitic efficacy and blood effects of formalin on Arapaima gigas (Pisces: Arapaimidae).

This study evaluated the in vitro and in vivo antiparasitic efficacy of formalin against Dawestrema cycloancistrium, the effects on the physiological response of Arapaima gigas and the residual action on fish muscle after 96h of exposure. As regards the in vitro assay, 0, 22, 44, 66, 88, 110, 330, 660 and 880 mg L-1 formalin were tested. After 1h of exposure to 660 and 880 mg L-1 formalin, there was a 100% mortality of D. cycloancistrium as well as after 2h of exposure at 330 and 110 mg L-1 and 3h of exposure at 44, 66 and 88 mg L-1. Concerning the in vivo test, when fish were exposed to formalin at 0, 220, 330, 440 and 550 mg L-1, there was 100% survival at all concentrations and exposure times evaluated. Baths of 1h with 440 and 550 mg L-1 formalin showed 93.3% and 99.3% efficacy respectively. However, the baths of 12h with 55 and 66 mg L-1 formalin had the efficacy of 44.5% and 55.5% respectively. In 1h baths with 220, 330, 440 and 550 mg L-1 formalin, hematocrit, hemoglobin, number of total erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, plasma glucose levels, cortisol, total proteins, chloride, calcium, sodium, potassium and magnesium of the fish presented no differences in relation to the control values. However, in baths of 12h with 33, 44, 55 and 66 mg L-1 formalin, there was a decrease in hematocrit, plasma levels of calcium and chloride, and increased levels of glucose and cortisol, depending on the concentration of formalin used. In the fish muscle, the formalin residue decreased after 96h in all concentrations and periods evaluated, returning to values close to the control ones. The results indicate that formalin had its efficacy successfully proved in the treatment against D. cycloancistrium at higher concentrations such as 440 and 550 mg L-1 formalin and shorter exposure time (1h) without compromising fish homeostasis and consumer food safety. Statement of relevance: The manuscript represents original research on use of formalin in vitro and in vivo for treating infection by monogenoidean Dawestrema cycloancistrium in Arapaima gigas, the giant fish from Amazon. In the fish, muscle the residue levels of formalin after exposure was also investigated. Formalin have efficacy in the treatment against D. cycloancistrium at higher concentrations (440 and 550 mg.L-1) of formalin and shorter exposure time (1h) and without compromising A. gigas homeostasis and consumer food safety

Crescimento inicial de mudas de Aspidosperma pyrifolium irrigadas com água com diferentes níveis de salinidade.

O objetivo do trabalho foi avaliar o efeito da salinidade no crescimento inicial de mudas de Aspidosperma pyrifolium.Edição dos Resumos do V Workshop de Tecnologia e Fisiologia de Sementes e Mudas, Petrolina, dez. 2014