This study evaluated the efficacy of albendazole, ivermectin, levamisole, mebendazole and praziquantel on monogeneans of Colossoma macropomum, based on in vitro and in vivo assays. In vitro assays indicated that albendazole (500, 100, 1,500 and 2,000 mg/L), ivermectin (200, 250, 300 and 350 mg/L) and levamisole (50, 75, 100 and 125 mg/L) were 100% effective against Anacanthorus spatulatus, Notozothecium janauachensis, Mymarothecium boegeri and Linguadactyloides brinkmanni, while mebendazole (125, 150, 175 and 200 mg/L) and praziquantel (5, 10, 15 and 20 mg/L) were ineffective. Fish mortality in 24 hr therapeutic baths with 500 mg/L of albendazole was 6.6%, but the behaviour of the animals remained unchanged, while 200 mg/L of ivermectin caused lethargy, signs of hypoxia and 100% mortality within 2 hr, and 125 mg/L of levamisole caused no mortality. The efficacy of 500 mg/L of albendazole was 48.6% in the 24 hr baths, while that of 125 mg/L levamisole was 88.2%. Although ivermectin showed in vitro efficacy, the lowest concentration used in baths was highly toxic to fish. Therefore, we recommend the use of 125 mg/L of levamisole to control and treat monogenean infestations on C. macropomum in fish farming.

The world population is estimated to reach close to 10 billion inhabitants by 2050, thus increasing the global demand for energy, drinking water and food (ONU, 2019). Given this scenario and the decline of natural fish stocks, aquaculture has been the subject of rapid development. Aquaculture has grown faster than other major food production sectors as it contributes to the supply of animal protein of high biological value for human consumption, job creation and income, thereby boosting the economic development of several countries (FAO, 2018).However, aquaculture activities around the world have suffered from outbreaks of parasitic diseases, which cause losses in production and affect profitability and sustainability (Assefa & Abunna, 2018).Losses in aquaculture caused by parasitic diseases are estimated at US $ 1.05-9.58 billion/years (Shinn et al., 2015). Losses from parasitic diseases are also attributed to stressful handling conditions, high stocking densities and inadequate water quality during the cultivation.Parasitic diseases in fish farming include those caused by monogeneans, which are ectoparasites with simple and direct life cycle.These ectoparasites can cause significant losses in farmed fish for

Global fish production is estimated to have reached around 179 million tons in 2018, of which 156 million tons were destined for human consumption, or 20.5 kg per capita/year. Aquaculture was responsible for 46% of total production, and 52% of fish for human consumption (FAO -Food & Agriculture Organization of the United Nations, 2020). Thus, fish farming directly or indirectly generates millions of jobs and produces several species of fish.Tambaqui Colossoma macropomum (Cuvier, 1818), the second most cultivated fish species in Brazil, is also produced throughout the Amazon, due to its strong zootechnical performance in

Realizar análise microbiológica da água de consumo distribuídos via tubulação hidráulica para as residências localizadas em um bairro alagado do município de Macapá - AP. Métodos: Estudo transversal, descritivo, quantitativo, realizado através de coletas de amostras de água de 23 residências em duplicata identificadas como (A e B), totalizando 46 amostras analisadas. Para a análise das coletas foi utilizado o método de Número Mais Provável, que estabelece a quantidade de coliformes por 100 mL, fornecendo informações a respeito da potabilidade da água. Resultados: A análise microbiológica das amostras coletadas das 23 residências revelou que 8 casas (34,8%) tiveram resultados positivos para coliformes totais e 6 casas (26.1%), positivos para coliformes termotolerantes. Em relação as bactérias heterotróficas, 13 casas (56,5) apresentaram resultados positivos, sendo que 11 dessas casas (84,6%) apresentaram resultados superiores a 500 UFC/mL. Foi observado a contaminação da água por coliformes fecais de algumas residências, em decorrência das encanações submersas e das precárias condições das instalações hidráulicas. Conclusão: Embora as casas sejam servidas por água da rede de abastecimento de tratamento da cidade, a falta de manutenção nas encanações e o contato com a água da área alagada, pode ser um dos fatores contribuidores para essas contaminações.

This study investigated the effects of diets supplemented with levamisole on monogeneans on the gills of Colossoma macropomum. Fish were fed with diets containing levamisole at concentrations of 0, 300, 600, 900 and 1200 mg kg-1 for 24, 96 and 240 h and the infection by Anacanthorus spatulatus, Notozothecium janauachensis and Mymarothecium boegeri were evaluated. None of the levamisole concentrations caused either mortality or behavioral alterations in fishes during 240 h of feeding. After 24 h of feeding with 1200 mg kg-1 of levamisole, the abundance of N. janauachensis decreased in comparison with treatments of 0, 300, 600 and 900 mg kg-1, as did the abundance of M. boegeri after 240 h of feeding with 1200 mg kg-1 of levamisole. The efficacy of 900 mg kg-1 of levamisole was only 55.7% after 96 h of feeding, but it was 84.6% after 240 h of feeding with 1200 mg kg-1. Our results show that 1200 mg kg-1 of levamisole for 10 days has good anthelmintic efficacy against monogeneans of C. macropomum. Since monogeneans elicit some of the worst problems in C. macropomum, this study has provided evidence of an effective control method that may be used in fish farms.