Essential Oil of Piper marginatum (Piperaceae) Against Monogeneans, and Its Hematological and Histopathological Effects on Colossoma macropomum.

PURPOSE: This study investigated the anthelmintic efficacy of therapeutic baths with the essential oil of Piper marginatum Jacq against the monogeneans Anacanthorus spathulatus Kritsky, Thatcher & Kayton, 1979, Notozothecium janauachensis Belmont-Jégu, Domingues & Laterça 2004, Mymarothecium boegeri Cohen & Kohn, 2005 and Linguadactyloides brinkmanni Thatcher & Krytsky, 1983 in Colossoma macropomum Cuvier, 1818, and its hematological and histopathological effects on this fish. METHODS: Short six therapeutic baths with 100 mg/L of the essential oil of P. marginatum and two control groups (water from the cultivation tank and water from the cultivation tank + 70% alcohol) were used for 20 min every two days. RESULTS: The therapeutic baths with 100 mg/L of the essential oil of P. marginatum had efficacy of 42.8% against monogeneans of C. macropomum gills. Toxicity was low for C. macropomum, because there were few physiological and histopathological changes that did not compromise the functioning of the gills of this fish. CONCLUSION: Short therapeutic baths with 100 mg/L of the essential oil of P. marginatum had low efficacy for controlling monogeneans in C. macropomum and thus cannot be recommended.

Essential oil of Piper hispidum (Piperaceae) has efficacy against monogeneans, and effects on hematology and gill histology of Colossoma macropomum.

This study investigated for the first time the effectiveness of therapeutic baths with essential oil (EO) of Piper hispidum against monogeneans Anacanthorus spathulatus, Notozothecium janauachensis, Mymarothecium boegeri and Linguadactyloides brinkmanni from the gills of Colossoma macropomum, as well as the hematological and histological effects on this fish. In therapeutic baths, 100 mg/L of P. hispidum essential oil and two control groups (water from the culture tank and water from the culture tank with 70% alcohol) were exposed for 1 h/day, with intervals of 48 hours for 3 days, and three replicates each were used. Therapeutic baths with 100 mg/L of P. hispidum essential oil had an efficacy of 78.6% against monogeneans. The toxicity of this essential oil was low, since there were a few physiological and histopathological changes that did not compromise the functioning of the gills of the fish. Therefore, 100 mg/L of P. hispidum essential oil was effective for controlling monogeneans in C. macropomum, when short therapeutic baths were used without compromising the health of the exposed fish.

Efficacy of Carapa guianensis oil (Meliaceae) against monogeneans infestations: a potential antiparasitic for Colossoma macropomum and its effects in hematology and histopathology of gills.

This study evaluated the efficacy of therapeutic baths with Carapa guianensis (andiroba) oil against monogeneans of Colossoma macropomum (tambaqui), as well as the hematological and histological effects on fish. Among the fatty acids identified in C. guianensis oil, oleic acid (53.4%) and palmitic acid (28.7%) were the major compounds, and four limonoids were also identified. Therapeutic baths of 1 hour were performed for five consecutive days, and there was no fish mortality in any of the treatments. Therapeutic baths using 500 mg/L of C. guianensis oil had an anthelmintic efficacy of 91.4% against monogeneans. There was increase of total plasma protein and glucose, number of erythrocytes, thrombocytes, leukocytes, lymphocytes and number of monocytes and decrease in mean corpuscular volume. Histological changes such as epithelium detachment, hyperplasia, lamellar fusion and aneurysm were found in the gills of tambaqui from all treatments, including controls with water of culture tank and water of culture tank plus iso-propyl alcohol. Therapeutic baths with 500 mg/L of C. guianensis oil showed high efficacy and caused few physiological changes capable of compromising fish gill function. Results indicate that C. guianensis oil has an anthelmintic potential for control and treatment of infections by monogeneans in tambaqui.

Hematological and biochemical responses of pirarucu (Arapaima gigas, Arapaimidae) fed with diets containing a glucomannan product derived from yeast and algae / Respostas hematológicas e bioquímicas de pirarucu (Arapaima gigas, Arapaimidae) alimentado com dietas contendo mananoligossacarídeos derivados de leveduras e algas

ABSTRACT The hematological and biochemical responses of pirarucu fingerlings (Arapaima gigas) fed with diets containing different concentrations of a glucomannan product derived from yeast and algae were evaluated in order to ascertain the effect of these diets on fish physiology. Four treatments were conducted, with three replications, with 12 fish in each tank. The product evaluated (MycosorbA+(r)) was incorporated into the commercial diet, at four concentrations: 0, 1, 2 and 4 g.kg-1, called M0%, M0.1%, M0.2% and M0.4%, respectively. After 45 days of feeding, blood samples from six fish in each replicate were collected to perform the analyses. Their weight and length were determined to calculate the condition factor and weight gain, but no differences (P > 0.05) were observed among the treatments. No changes to the hematocrit, hemoglobin or erythrocyte levels or to the hematimetric indices of the pirarucus were observed. The glucose and triglyceride levels of the pirarucus in the M0.1% and M0.2% groups were significantly lower than those of the M0% group. The M0.2% group showed higher albumin levels (P < 0.05) than M0% and M0.4%. The M0.4% group showed a total cholesterol level that was significantly higher than in all other treatments. MycosorbA+(r) contributed towards increasing the levels of defense cells in A. gigas. It would be possible to use this product at concentrations of between 0.1% and 0.2%, given that they increase the levels of some defense cells and plasma albumin concentrations, without changes to hematological parameters, cholesterol and triglyceride plasma levels or condition factor.

RESUMO As características hematológicas e bioquímicas de alevinos de pirarucu Arapaima gigas alimentados com diferentes concentrações de mananoligossacarídeos derivados de leveduras e algas na dieta foram avaliadas para verificar o efeito sobre sua fisiologia. Quatro tratamentos foram conduzidos com três repetições (12 peixes em cada). O produto avaliado (MycosorbA+(r)) foi incorporado à ração comercial, em quatro níveis: 0, 1, 2 e 4 g kg-1 de ração, denominados M0%, M0,1%, M0,2% e M0,4%, respectivamente. Após 45 dias de alimentação, amostras de sangue de seis peixes de cada repetição foram coletadas para realização das análises. O peso e comprimento foram obtidos para cálculo do fator de condição e ganho de peso, entretanto, não foram observadas diferenças (P>0,05) entre os tratamentos. Assim como não foram observadas alterações nos valores de hematócrito, hemoglobina, eritrócitos e índices hematimétricos dos pirarucus. A concentração de glicose e triglicérides dos pirarucus dos grupos M0,1% e M0,2% foram significativamente menores que o tratamento M0%. Os peixes do tratamento M0,2% apresentaram níveis de albumina maior (P<0,05) que do M0% e M0,4%. Os peixes alimentados com M0,4% mostraram nível de colesterol total significativamente maior que todos os demais tratamentos. MycosorbA+(r) contribuiu para o aumento das células de defesa de A. gigas, podendo ser utilizado nas concentrações de 0,1% a 0,2%, devido ao aumento do número de certas células de defesa e dos níveis plasmáticos de albumina e por não ter sido observadas outras alterações nos parâmetros hematológicos, nos níveis plasmáticos de colesterol e triglicérides e no fator de condição.

Contaminação por metais pesados em peixes e água da bacia do rio Cassiporé, Estado do Amapá, Brasil / Heavy metal contamination in fish and water from Cassiporé River basin, State of Amapá, Brazil

A participação dos metais pesados nas reações químicas do metabolismo dos peixes tornou esses elementos um dos principais focos nos estudos de contaminação. O objetivo deste estudo foi determinar as concentrações dos metais Cd, Cr, Cu, Pb, Zn e Hg no tecido muscular de peixes da bacia do rio Cassiporé (Estado do Amapá) e ambiente, visando avaliar os riscos de contaminação. As concentrações de Cd em Plagioscion squamosissimus (1,061 µg g-1) e Pb em Poptella compressa (4,280 µg g-1) apresentaram valores que ultrapassam os limites estabelecidos pela legislação brasileira. As concentrações de Cr em P. compressa (0,937 ± 0,5 µg g-1), Pimelodella cristata (0,463 ± 0,03 µg g-1) e Cyphocharax gouldingi (0,364 ± 0,12 µg g-1), bem como de Hg em P. squamosissimus (0,670 µg g-1), Pseudoplatystoma fasciatum (0,630 µg g-1), Hoplias malabaricus (0,570 µg g-1 e Serrasalmus rhombeus (0,548 µg g-1) foram acima do limite legal. A coluna d'água apresentou altas concentrações de metais pesados em todos os pontos analisados, mostrando uma contaminação dessa bacia. Portanto, essas elevadas concentrações de metais pesados no ambiente e tecido muscular dos peixes indicam um elevado grau de contaminação na bacia do rio Cassiporé e risco a saúde do homem.

Heavy metals participate in chemical reactions of fish metabolism, which makes these elements a major focus on contamination studies. The objective of this study was to determine the concentrations of heavy metals Cd, Cr, Cu, Pb, Zn and Hg in muscle tissue of fish of Cassiporé River Basin (State of Amapá) and environment, aiming at assessing the risk of contamination. The concentrations of Cd in Plagioscion squamosissimus (1.061 µg g-1) and Pb in Poptella compressa (4.280 µg g-1) had values that exceed the boundaries established by Brazilian law. The Cr concentration in P. compressa (0.937 ± 0.5 µg g-1), Pimelodella cristata (0.463 ± 0.03 µg g-1) and Cyphocharax gouldingi (0.364 ± 0.12 µg g-1) and Hg in P. squamosissimus (0.670 µg g-1), Pseudoplatystoma fasciatum (0.630 µg g-1), Hoplias malabaricus (0.570 µg g-1 e Serrasalmus rhombeus (0.548 µg g-1) were above the legal limit. The water column showed high concentrations of heavy metals in all analyzed points, showing a contamination of this river basin. Therefore, the high concentrations of heavy metals in the environment and muscle tissue of fish indicate a high degree of contamination in the Cassiporé river basin and risk to human health.