Franmir Rodrigues Brandão

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

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.

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.

Uso de sal durante o transporte de juvenis (1kg) de pirarucu (Arapaima gigas)

Pirarucu is a native fish of the Amazon basin, widely used in culture systems in some parts of Brazil. The objective of this work was to test table salt as a stress mitigator during transportation of pirarucu juveniles (1kg). Fish were transported by two different systems: boxes without addition of oxygen (open system) and closed oxygen filled plastic bags (closed system). To both systems fish were transported at three different treatments: control and two table salt concentration (3 and 6 gL-1). After transportation, fish were stocked in ponds to monitor recovery. Metabolic (cortisol, glucose and lactate) and hematological (hematocrit) parameters were analyzed. The table salt was not efficient in mitigating stress response during the both tested transport system.

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.

Uso do probiótico Efinol®L durante o transporte de tambaqui (Colossoma macropomum)

The effectiveness of the addition of a potentially stress reducing probiotic during transportation of tambaqui juveniles was studied. Fish were transported with (20mg/L) and without probiotic in the water. The transport duration was 16 hours. After transportation, fish were placed in 150L tanks to monitor their recovery for 96-hours. The following stress parameters were evaluated: glucose, hematocrit, and hemoglobin, and also some water quality parameters. The responses of glucose presented similar pattern between the treatments. Glucose concentrations significantly increased after transportation, kept high for 24 and 48-hours after transportation, and returned to control-like concentration at 96-hours after transportation. Hemoglobin did not present significant difference during or after transportation. Hematocrit significantly increased in probiotic-free treatment at 24 and 48 hours after transportation. The stress response in tambaqui was similar between the tested treatments, indicating that the used probiotic was not efficient in suppressing the stress during transportation; however, it was able to mitigate post-transportation stress response.