Edsandra Campos Chagas

Densidade de estocagem de juvenis de tambaqui durante a recria em tanques-rede

The objective of this work was to determine the adequate stocking density to second growth phase of tambaqui (Colossoma macropomum ) juveniles in cage. Twelve cages of 1 m 3 were used to stock fish in four different densities, with three replicate: 200, 300, 400 and 500 fish/m 3 . Fish were fed with commercial diets with 36% of crude protein six times a week, in three daily meals during 60 days. The growth in weight and in length, coefficient of variation of length, specific growth rate and glucose were analyzed at 30 and 60 days of rearing. At the end of the experiment final productivity parameters were evaluated: survival, feed conversion, weight gain and production per area. Physical-chemical parameters of water were evaluated each seven days. After 60 days, the growth in weight and length was higher in the density of 200 fish/m 3 compared to the density of 500 fish/m 3 . The coefficient of variation of length, specific growth rate and glucose present no significant differences among the treatments at 30 and 60 days. Survival, feed conversion and weight gain were similar for all densities. The production per area was higher in the two highest densities. Results indicate that the density of 400 fish/m 3 is

Efeito da vitamina C no ganho de peso e em parâmetros hematológicos de tambaqui

(3) Resumo – O objetivo deste trabalho foi avaliar o efeito da suplementacao dietaria com acido L-ascorbico (vitamina C) no ganho de peso e em parâmetros hematologicos de juvenis de tambaqui, Colossoma macropomum. Apos dez semanas, em que foram alimentados com dietas contendo 0, 100 e 500 mg de acido L-ascorbico por kg de racao, os peixes foram capturados e imediatamente anestesiados para a coleta de sangue da veia caudal e determinacao dos parâmetros hematologicos. Animais alimentados com maiores niveis de ascorbato mostraram pesos corporeos maiores, melhores taxas de conversao alimentar e sobrevivencia. A asencia de acido L-ascorbico na racao, alem de causar reducao nos valores de hematocrito e no numero de eritrocitos, que caracteriza anemia, provocou aumento no volume corpuscular medio, na hemoglobina corpuscular media e na concentracao de hemoglobina corpuscular media. Esses resultados revelam a importância do acido L-ascorbico na dieta dos juvenis de tambaqui. O nivel de 100 mg de acido L-ascorbico/kg de racao e adequado, garantindo bom ganho de peso e manutencao da homeostase do organismo. Termos para indexacao: Colossoma macropomum, suplemento alimentar, nutricao animal, piscicultura. Effect of vitamin C on weight and hematology of tambaqui

Respostas de estresse em pirarucu (Arapaima gigas) durante práticas de rotina em piscicultura

Pirarucu is an obligatory air breathing fish native to the Amazon basin. In rearing conditions it reaches up to 10 kg in one year, being one of the fish with the greatest potential for farming in the Amazon. The aim of this study was to verify stress responses in pirarucu during routine aquaculture practices. Three experiments were carried out: 1) transport; 2) crowding; and 3) exposure to ammonia. Parameters of the energy metabolism (glucose and lactate), hormonal (cortisol), and hematological (hematocrit) were analyzed. All experiments caused alterations in the physiological parameters of pirarucu. The stress responses during transport are similar to crowding. However, the magnitude of the responses to crowding was higher. Ammonia exposure does not cause an immediate alteration in the physiological parameters, with a latency period in the stress responses. From the observed results it is possible to conclude that alterations in the metabolic parameters occur during the more intense management periods and probably can be prevented adopting best management practices.

Produtividade de tambaqui criado em tanque-rede com diferentes taxas de alimentação

This research was aimed at evaluating the effect of feeding rates on productivity and blood glucose levels, triglycerides and total plasma proteins of tambaqui (Colossoma macropomum) reared in cages. Tambaqui juveniles were reared during 150 days fed at 1, 3 and 5% of body weight per day allocated with two meals, six days a week. The feeding rates did not show any effects on the condition factor and survival. Weight gain and production of fish that were fed at 3 and 5% were significantly higher than the fish that received 1% of body weight per day. Although, feed conversion was significantly higher at the ratio of 1% of body weight per day, and the values of feed conversion obtained at the ratios of 3 and 5% per se make the culture of tambaqui unprofitable. No alterations were observed in the levels of blood glucose, triglycerides and total plasma protein of tambaqui from the different treatments. The feeding-ratio productivity adequate for tambaqui juveniles, when reared in cages in varzea lakes with an initial weigh of 200g, is 1% of body weight per day.

Efeito do volume do tanque-rede na produtividade de tambaqui (Colossoma macropomum) durante a recria

O objetivo desta nota foi avaliar o efeito do volume do tanque-rede na produtividade de juvenis de tambaqui durante a recria. Juvenis de tambaqui foram criados por 60 dias, na densidade de 300 peixes/m3, em tanques-rede de dois diferentes volumes: 1 e 6 m3. Foram avaliados parâmetros de crescimento e de produtividade final. Nao houve diferenca no crescimento em peso e em comprimento. O coeficiente de variacao do comprimento foi significativamente menor para os peixes do tanque-rede pequeno. A sobrevivencia, producao por volume e o ganho de peso nao diferiram entre os tratamentos. Os peixes do tanque de maior volume foram significativamente mais eficientes na conversao alimentar. A recria pode ser realizada em tanques dos dois volumes testados sem prejuizo zootecnico para o criador.

Desempenho de tambaqui cultivado em tanques-rede, em lago de várzea, sob diferentes taxas de alimentação

The objective of this work was to estimate the effect of feeding rates, 5%, 7.5% and 10% of body weight per day, on growth performance and metabolic parameters of tambaqui, Colossoma macropomum, reared in cages located in a floodplain lake. Fish fed at 5% of body weight per day presented better feed conversion; total plasma protein values, after 90 days, were significantly lower than in other treatments. A daily feeding rate of 5% body weight, for tambaqui juveniles reared in cages in floodplain lakes, allows a satisfactory performance.

Efeito de banhos terapêuticos com formalina sobre indicadores de estresse em tambaqui

A formalina tem sido usada no controle de doencas parasitarias, porem existem poucas informacoes sobre o efeito secundario desse produto sobre os peixes. O objetivo deste trabalho foi avaliar o efeito de concentracoes terapeuticas de formalina na homeostase de tambaqui (Colossoma macropomum Cuvier 1818) por meio de indices fisiologicos. Os banhos terapeuticos foram realizados em tanques de 100 L, com solucoes de formalina a 0, 100, 150, 200 e 250 mg/L, em tempos de exposicao de 0, 30, 60 e 120 minutos; a recuperacao dos animais em tanques, sem adicao de formalina a agua, foi avaliada apos 24 horas. Foi realizada a coleta de sangue da veia caudal dos peixes para determinacao de glicose, cloretos, sodio, potassio e calcio. Os peixes nao exibiram sinais de estresse na concentracao de 100 mg/L de formalina em todos os tempos de exposicao. Contudo, banhos de 200 e 250 mg/L causaram aumentos significativos nos niveis de glicose apos 30 minutos de exposicao. Os resultados sugerem que a formalina pode ser usada nas concentracoes de 100 e 150 mg/L em banhos de 30, 60 e 120 minutos e nas concentracoes de 200 e 250 mg/L em banhos de ate 30 minutos sem comprometer a homeostase do tambaqui.

Trichodinidae in commercial fish in South America.

Ciliates of the family Trichodinidae are protozoan parasites of importance for fish farming in South America, given that at high infestation levels, they cause significant mortality among farmed fish. Although data on economic losses due to parasitosis are not available for South America, mortality outbreaks correlated to trichodinids are very common in the tilapia production chain, especially in Brazil, the largest aquaculture chain in the country. In Brazil in the past, trichodinids were considered only as Trichodina sp. Today, they have been better studied and identified taxonomically in wild and farmed fish. However, in other countries in South America, trichodinids continue to be described only as Trichodina sp. This review presents the history of occurrences of trichodinids in fish of interest in South America, highlighting 15 new species that have been described in three genera in Brazil, along with information on parasite-host-environment relationships, diagnostic methods and treatments. The occurrence of parasitic ciliates must be correlated with farming conditions such as stress factors, water quality, seasonality, age and host immunity to elucidate the critical points of each production system. Furthermore, for tropical fish, studies on treatment against trichodinid species are needed to provide support for approval of antiparasitic medications for use in fish farming. However, it is recommended that the production sector use intensive production systems that are more sustainable, with biosafety protocols, to increase production and productivity.

Efeito do cloreto de sódio sobre as respostas fisiológicas e controle de helmintos monogenóides em tambaqui (Colossoma macropomum)

O objetivo deste trabalho foi avaliar o efeito do sal (NaCl) sobre as respostas fisiologicas e controle de helmintos monogenoides em tambaqui (Colossoma macropomum). Para isso, juvenis de tambaqui (42,38 ± 0,47 g; 13,90 ± 0,06 cm) foram transferidos para tanques de 350L e aclimatados por um periodo de 24 horas. Os ensaios foram conduzidos utilizando as concentracoes de 0, 2, 4, 6 e 8 g de sal comum L-1 de agua, nos tempos de exposicao de 30, 60 e 120 minutos, com tres repeticoes por tratamento. A tolerância dos tambaquis ao sal e a eficacia deste sobre os helmintos monogenoides foi avaliada mediante analise dos indicadores fisiologicos (glicose, cloretos, sodio e potassio plasmatico) e parasitologicos (numero total de parasitas e prevalencia). Tambaquis expostos a 4 g NaCl L-1 por 120 minutos, 6 e 8 g NaCl L-1 por 60 e 120 minutos apresentaram maior elevacao da glicose plasmatica e na concentracao de 8 g NaCl L-1 por 120 minutos maiores niveis de cloreto plasmatico. A prevalencia de monogenoides nas brânquias foi de 100% e todas as concentracoes de sal avaliadas neste estudo nao foram eficazes na reducao dos helmintos monogenoides em tambaqui.

Antiparasitic activity, histopathology and physiology of Colossoma macropomum (tambaqui) exposed to the essential oil of Lippia sidoides (Verbenaceae)

In vivo and in vitro antiparasitic activity of the essential oil of Lippia sidoides and blood and histological alterations were assessed in Colossoma macropomum (tambaqui). Essential oil concentrations of 10, 20, 40, 80, 160 and 320mg/L were assayed in vitro against monogenoideans Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri from fish gills. Lippia sidoides essential oil concentrations of 320 and 160mg/L were 100% effective against monogenoideans in 10min and 1h of exposure, respectively. However, the effectiveness of 100% concentrations of 80mg/L and 40mg/L occurred in 3 and 6h, respectively. In the in vivo tests, juvenile fish were submitted to 60min of baths with 10mg/L and 15min of baths with 20mg/L of the essential oil of L. sidoides. These therapeutic baths were not efficient against Ichthyophthirius multifiliis, and monogenoideans present in the gills of C. macropomum. In addition, 10 and 20mg/L of the essential oil of L. sidoides caused an anesthetic effect on the fish and did not influence total glucose and protein plasma levels; however, it decreased the number of total erythrocytes in fish exposed to the higher concentration of this essential oil. Severe alterations and irreversible damage were observed in the fish gills just after L. sidoides essential oil baths and after 24h of recovery. The most recurrent lesions found were hyperplasia and fusion of the lamellar epithelium, vasodilation, detachment of the gill epithelium and lamellar aneurism, epithelial breakdown with hemorrhage, congestion, edema and necrosis, proliferation of the mucous cells and chloride cells and lamellar hypertrophy. Therefore, since the essential oil of L. sidoides has in vitro antiparasitic activity and low concentrations of it have shown toxic effects, the bioactive potential of its main chemical components should be investigated, as well as more efficient forms of its administration in therapeutic baths in order to eliminate fish parasites.