This study evaluates the inclusion of lycopene in the commercial diet for Nile Tilapia exposured to a stressor. For 60 days, ¢sh diet was supplemented with lycopene (600 mg kg À 1 diet) and at the end, subjected to con¢nement for 90 min. Zootechnical parameters (weight gain, speci¢c growth rate and intake), hormonal (cortisol level), biochemical {enzyme activity and lipid peroxidation level [thiobarbituric acid (TBARS)]} and physical (instrumental colour) parameters were also evaluated. Supplementation with lycopene did not alter zootechnical parameters. In uncon¢ned ¢sh, catalase (CAT) activity was reduced in the white muscle of ¢sh fed with lycopene; however, in red muscle, it was not altered. In ¢sh under con¢nement, plasma cortisol increased as well as CAT, glutathione reductase (GR) and lactate dehydrogenase (LDH) activity in both muscles. Lipid peroxidation of the ¢llet also displayed higher values. However, the lycopene supplementation abolished the e¡ects of con¢nement available through cortisol levels, remaining unchanged in the above parameters, activity of CAT, GR and LDH in both muscles and TBARS content of the ¢llet; in addition, it did not induce alteration of ¢llet coloration. Inclusion of lycopene in commercial feed reduces the impact of con¢nement and does not alter the zootechnical parameters; additionally, no modi¢cation of the ¢llet colour from juvenile Nile tilapia was observed.

RESUMO -Estudaram-se as respostas comportamentais e fisiológicas de juvenis de tilápia do Nilo (Oreochromis niloticus) submetidos a diferentes cores de ambientes e situações sociais. Os animais foram mantidos isolados em aquários recobertos com papelcartão colorido, compondo cinco tratamentos (preto, verde, marrom, azul e branco).Utilizando-se filmagens semanais realizadas em etapas distintas e alternadas (isolamento e presença de um espelho), registraram-se os seguintes parâmetros: distribuição na coluna d'água, coloração, atividade locomotora, confrontos agonísticos, posição da nadadeira dorsal e postura. Para quantificação dos níveis plasmáticos de glicose, triglicerídeos, proteínas totais e cortisol, coletaram-se amostras de sangue após cada filmagem. As médias obtidas foram analisadas estatisticamente pelo método não-paramétrico de Kruskal-Wallis. Os peixes mantidos nos ambientes preto e verde apresentaram baixas freqüências de confrontos agonísticos, enquanto aqueles mantidos no ambiente branco, altas freqüências, porém com redução do padrão ameaça e não alterando sua locomoção. Animais submetidos às cores marrom e azul apresentaram as mais altas freqüências de comportamentos agonísticos e maior atividade locomotora. Os peixes permaneceram em todos os tratamentos com a coloração clara, ocupando, com maior freqüência, a região inferior da coluna d'água. Não foram observadas diferenças significativas para as concentrações de glicose, triglicerídeos e proteínas totais entre os tratamentos, porém obteve-se elevado nível de cortisol para os animais mantidos nos ambientes azul e marrom, quando submetidos à reflexão da própria imagem em espelho. Estes resultados mostraram que existe influência da cor do ambiente sobre o estresse social, em particular nas interações agonísticas entre coespecíficos e na concentração do hormônio cortisol. Concluiu-se que as cores verde e preta são recomendadas à manutenção da espécie, por amenizarem as interações agonísticas e o estresse, enquanto a marrom e azul devem ser evitadas por estimularem estas respostas.Palavras-chave: agressividade, comportamento, cor do ambiente, estresse social, metabolismo, Oreochromis niloticus Effect of Background Color on the Social Stress of Nile Tilapia (Oreochromis niloticus)ABSTRACT -It was studied the behavior and physiologic answers of juvenile of Nile tilapia, Oreochromis niloticus, submitted the different backgrounds colors and social situations. The animals were maintained isolated in fishbowls covered with colored paper-card, composing five treatments (black, green, brown, blue and white). Through weekly filmings and in different and alternate stages (isolation and presence of a mirror), it enrolled the following parameters: distribution in the column of water, coloration, motility, agonistic behaviors, position of the dorsal fin and posture. For quantification of the glucose, triglycerides, total proteins and cortisol levels, were collected samples of blood after each filming. The obtained averages were analyzed statistically through the ...

The anaesthetic potential of menthol was evaluated in lambari Astyanax altiparanae by exposing fingerlings to concentrations 50, 100, 150, 200, 250 and 300 mg L À1 and measuring the induction and recovery times to deep anaesthesia, the mortality rates during and 96 h after procedure and after 6 min of continuous exposure. The effect of menthol on stress responses were evaluated by comparing glucose and cortisol levels of juveniles subjected to anaesthesia (50 mg L À1 ), stress (air exposure) or pre-anaesthesia associated to stress. All concentrations induced deep anaesthesia within 0.5 to 1 min, with recovery between 1.83 and 4.16 min, without mortality during the induction or up to 96 h after exposure. Induction time decreased and recovery time increased linearly as the menthol concentration increased. Continuous exposure to 50, 100 and 150 mg L À1 concentrations resulted in mortality rates of 0%, 20% and 80% respectively. Anaesthesia or air exposure increase blood glucose but prior anaesthesia with menthol suppressed the elevation of cortisol caused by stress. Menthol has an anaesthetic effect and attenuates the stress response in lambari and 50 mg L À1 is the most effective concentration for inducing deep anaesthesia in 1.0 min, safe for up to 6 min exposure.

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RESUMO -Estudou-se a habilidade de juvenis de tilápia do Nilo, Oreochromis niloticus, em regular a ingestão protéica. Mil exemplares com peso e comprimento de 13,93g ± 0,87g e 8,8cm ± 0,47cm, respectivamente, revertidos sexualmente, foram distríbuídos em oito grupos de 125 peixes, em aquários de 1.000 L com renovação contínua de água e dotados de dois alimentadores de demanda. Duas rações isoenergéticas (2.800 kcal/kg) contendo, respectivamente, 40% e 15% PB foram oferecidas diariamente, ad libitum, em combinações que caracterizaram quatro tratamentos: A: ração de 15% PB de um lado e de 40% PB do outro do aquário; B: idêntico ao tratamento A com inversão dos lados; C: ração de 15% PB fornecida em dois alimentadores; e D: ração de 40% PB fornecida em dois alimentadores. O delineamento em quadrado latino permitiu que os peixes fossem submetidos a cada tratamento durante quatro fases de 15 dias (I, II, III e IV). Entre as fases, houve intervalo de uma semana, quando os peixes receberam dieta contendo 30% PB nos dois alimentadores. O consumo alimentar dos peixes, registrado diariamente, não diferiu significativamente entre os tratamentos A e B. Porém, quando foram apresentadas simultaneamente as dietas contendo mesmo teor de PB (Tratamentos C e D), observou-se consumo significativamente maior da ração contendo 15% de PB (Tratamento C). O ajuste em porcentagem da proteína ingerida pelos peixes revelou média de 24% de PB. Os resultados confirmaram a hipótese de que a tilápia do Nilo apresenta habilidade em regular a ingestão dietética protéica por meio de livre escolha.Palavras-chave: comportamento alimentar, livre escolha, Oreochromis niloticus, proteína, tilápia do Nilo Hability of Protein Intake Regulation in Nile Tilapia, Oreochromis niloticusABSTRACT -The free-choice feed and regulation of protein intake were investigated in juveniles reverted males of tilápia do Nilo, Oreochromis niloticus. During the experiment 1000 fish (reverted males) with similar weigth and length were maintained in eight aquariuns supplied with recirculated water (groups of 125 fish each aquarium). Fish were fed by demand-feeders, containing the two experimental diets, formulated to contain 15% and 40% protein each and distributed in four treatments (A: 15% protein diet on one hand and 40% protein diet on the other hand, B: alike in A, therefore with an inversion on both hands, C: the two feeders supplied with 15% protein diet, D the two feeders supplied with 40% protein diet) The Latin Square was the estatistical method used for the experiment, and the treatments were distributed into four stages (I, II, III and IV). A one week stop after each stage was stipulated and the fish received a 30% protein diet. The results showed that no differences about the intake was detected between fish fed by diets containing 15% and 40% protein in the same aquarium. However, with same diets in the tanks ( Treatment C and D), the animals that were fed with the 15% protein diet showed better feed intake. The percentage of regulated protein during the exper...

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The efficacy of a point-of-care (POC) blood glucometer (Accu-Chek Active®) was evaluated in adult lambaris (Astyanax altiparanae), comparing the values obtained by this equipment to those obtained by the laboratory enzymatic method. The glycemia of adult males and females and the variations resulting from transporting in juveniles were also evaluated 0, 1, 24, 48 and 72 hours after procedure. Data were submitted to ANOVA, comparing the means by the Tukey´s Test (P > 0.05) and a regression analysis was performed to establish the correlations between values obtained by the two methods. The blood glucose values obtained by POC meter were 11.2% lower in absolute terms, but did not differ significantly from those recorded by the laboratory enzymatic method, with linear correlation (R = 67.7%) between the methods. Higher glucose levels were recorded for males; glycemia increased 334.3% immediately after transportation, remained elevated (113.3%) up to 48 hours and returned to basal levels (fasting) after 72 hours. It was concluded that POC Accu-Chek Active® is an effective tool for glucose determination in lambari; there are sex-dependent differences in relation to blood glucose levels; the species is sensitive to transporting stress and glycemia is an immediate and appropriate physiological indicator for this evaluation.

The effects of clove oil anaesthetic on mitigating the physiological responses to air exposure, a stressful and routine situation in fish farming, laboratory conditions and sport fishing (catch and release), were evaluated in lambari (A. altiparanae). Adult females (n = 80) were randomly sorted to receive one of four treatments: control, anaesthesia (clove oil 50 mg/L), stress (5 min air exposure) and pre‐anaesthesia associated to stress. Their cortisol, glucose, lactate and haematocrit levels, the hepatosomatic index (HSI), liver and muscle glycogen, lipid peroxidation and the enzymatic activity of lactate dehydrogenase (LDH), catalase (CAT) and glutathione reductase (GR), were recorded. Glucose levels increased (53.9%) after anaesthesia and/or stress. The stress situation increased plasma cortisol (146.6%), lactate (294.6%) and lipid peroxidation in white muscle (45%) and decreased glycogen in white muscle (40.1%). The haematocrit increased after stress or anaesthesia (7.9%) while the liver glycogen and HSI did not change. Anaesthesia or stress did not affect the LDH but reduced the activity of CAT (46.1%) and GR (30.3%). We concluded that the anaesthetic clove oil in the concentration 50 mg/L modulates the physiological responses to air exposure stress improving the welfare; air exposure and clove oil affect the antioxidant defences of lambari; the activity of CAT and GR and the concentration of MDA can be used as biomarkers of stress in A. altiparanae.