To investigate the impact of different dietary lipid sources on fillet composition and lipid transport, we conducted a feeding trial and evaluated the proximate composition of muscle tissue, fatty acid profiles, total cholesterol (in muscle and plasma), triglycerides, and lipoprotein concentrations in Nile tilapia, Oreochromis niloticus. Five semi‐purified diets, containing different oils (soybean – SO, corn – CO, linseed – LO, fish – FO, and olive – OO), were supplied to tilapia for 160 d. Fish fed with LO and FO diets had a lower percentage of total lipids in muscle compared with the others (P < 0.05). The highest percentage of protein was found in fish fed with FO diet (P < 0.05). The muscle fatty acid profile was influenced differently by diets (P < 0.05). The group supplemented with SO and CO had a higher concentration of 18:2n‐6, whereas the fish fed with LO diet had a higher level of 18:3n‐3 and those that received the FO diet had more 22:6n‐3 in comparison with those supplemented with vegetable oils. Plasma lipid transport was also affected by the diets: the fish fed with FO diet had higher total cholesterol and high‐density lipoprotein and lower very‐low‐density lipoprotein concentrations (P < 0.05).

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RESUMOConduziu-se este trabalho com o objetivo de avaliar a viabilidade técnica do uso de zooplâncton enriquecido na alimentação de pós-larvas de pacu (Piaractus mesopotamicus). Na Estação Ambiental de Itutinga, da Companhia Energética de Minas Gerais (CEMIG), foi realizada, durante 5 dias, a larvicultura de pacu, usando 30 caixas plásticas com capacidade de 30 litros de água e renovação contínua, em uma densidade de 10 pós-larvas por litro; foram avaliados 6 tratamentos de alimentação: zooplâncton sem enriquecimento, zooplâncton com 4 diferentes níveis de enriquecimento (0,1; 0,5; 1,0; 1,5g de óleo de peixe) e náuplios de artêmia, em um delineamento em blocos casualizados com 6 tratamentos e 5 repetições. Foram avaliados os parâmetros de desempenho nas pós-larvas, comprimento, peso, sobrevivência e resistência ao estresse. Os resultados demonstraram que o uso de zooplâncton enriquecido é viável na larvicultura de pacu, permitindo adequado desempenho das pós-larvas quanto ao comprimento, à sobrevivência e à resistência ao estresse.Termos para indexação: Aqüicultura, nutrição, alimento vivo, zooplâncton, larvicultura, pacu. ABSTRACTThe objective of this study was to evaluate the technical viability of the ooplankton enriched used in the feeding of pacu (Piaractus mesopotamicus) pos-larvaes. In the Environmental Station of Itutinga of the Energy Company of Minas Gerais (CEMIG) this experiment was developmented, for 5 days last , the pacu larvicultura, by using 30 plastic boxes with capacity of 30 liters of water and continuous renewal, in a density of 10 powder-larvas per liter; they were appraised 6 feeding treatments: ooplankton without enrichment, ooplankton with 4 different enrichment levels (0,1; 0,5; 1,0; 1,5 g of fish oil) and artêmia náuplios, in a randomly blocks design with 6 treatments and 5 repetitions. The performance of larvaes as well as length, weight, survival and resistance to the stress were evaluated. The results shown that the ooplankton enriched is viable in the pacu (Piaractus mesopotamicus) pos-larvaes performance in terms of length , survival and the resistance to the stress.

RESUMO -Com o objetivo de avaliar a influência da concentração de benzocaína na indução e recuperação da anestesia em tilápias-do-nilo (Oreochromis niloticus) de diferentes comprimentos, desenvolveu-se um experimento em blocos casualizados, em esquema fatorial 4 × 4, composto de quatro comprimentos de peixes (6; 10; 14 e 18 cm de comprimento total) e quatro concentrações de benzocaína (60; 120; 180 e 240 mg por litro de água). A indução e a recuperação da anestesia foram divididas em três estágios, de acordo com o comportamento dos peixes sob efeito do anestésico, registrando-se o tempo de permanência em cada estágio. As diferenças de comprimento não influenciaram de forma significativa os tempos de anestesia e recuperação. Regressões lineares com plateau foram geradas para estimar o ponto em que o aumento da dose deixou de ter efeito. Durante a indução à anestesia, o plateau ocorreu na concentração de 132 mg/L e o tempo estimado para atingir a sedação total (estágio 3) foi de 86 segundos. Para permanência do peixe sob sedação total, é necessária concentração de benzocaína de 190 mg/L e o tempo estimado de permanência neste estágio é de 91,1 segundos. Concentrações superiores a 190 mg de benzocaína por litro de água não produzem efeitos que justifiquem seu emprego.Palavras-chave: anestésico, aquicultura, comprimento, estágio Effect of benzocaine concentration and fish size on anesthesia and recovery in Nile tilapiaABSTRACT -To evaluate the influence of benzocaine concentration on the induction and recovery from anesthesia in different sized Nile tilapia (Oreochromis niloticus), it was developed a random block experiment design in 4 × 4 factorial consisted of four fish lengths (6; 10; 14 and 18 cm total lenght) and four benzocaine concentrations (60; 120; 180 and 240 mg of benzocaine per liter of water). The induction and the recovery from anesthesia were divided in three stages based on the behavior of the fishes under anesthetic effect. The time spent in each stage was recorded. Differences in length did not affect significantly the anesthesia and recovery time. Linear plateu regressions were generated to estimate the point which increases on anesthetic doses does not imply in further effects. During the anesthesia induction, the plateu occurred in concentration time of 132 mg/L, and estimated time of 86 seconds would be necessary to achieve the complete sedation (stage 3). For permanence of the fish under total sedation, it is needed 190 g/L benzocaine and estimated time of permanence in this stage is 91.1 seconds. Benzocaine concentrations above 190 mg/L do not produce any additional effects that justify its use.

To evaluate the effect of different dietary lipids on zebrafish reproduction, we examined parameters including ovary and carcass composition, oestradiol (E2) levels, eclosion rate and embryonic development. In our study, zebrafish were subjected to a 5-month feeding trial whereby olive (OLV), linseed (LIN), fish (FIS) or corn (CRN) oil were used to compose four isonitrogenous and isoenergetic diets. A positive correlation was found between ovary EPA and whole-body E2 concentration (P = 0.005). The developmental dynamics was affected by dietary lipids and embryos from CRN treatment females; which had higher percentage of ARA in ovary (1.48 AE 0.44%) (P = 0.015), developed faster at 8-9 h postfertilization (hpf) than the ones originated from females receiving other diets (P = 0.0069). This effect was not sustained during later observation periods, suggesting ARA may act as a modulator of developmental dynamics only during initial phases. There was no clear effect of dietary lipid source on ovary protein content (P = 0.304) and eclosion rates at 72 hpf (P = 0.0623). Dietary fatty acids play an important role in reproductive outcome; however, additional studies are necessary to elucidate the mechanisms by which HUFA affect embryonic development.

Efeito da vitamina C sobre o hematócrito e glicemia de alevinos de tilápia-do-nilo (Oreochromis niloticus) em transporte simulado RESUMOAvaliou-se o efeito do ascorbato sobre o hematócrito e glicemia em alevinos de tilápia nilótica (Oreochromis niloticus) submetidos à simulação de práticas relacionadas ao transporte. Foram utilizadas três dietas experimentais com diferentes níveis de vitamina C (16, 500 e 1000mg de vitamina C/kg), fornecidas durante os 14 dias anteriores à simulação do transporte que se estendeu por 14 horas. O tratamento que continha 16mg de vitamina C/kg foi o que apresentou a glicemia mais elevada logo após a simulação, 108,5mg/dl imediatamente após a simulação e 91mg/dl 12 horas após a simulação. A concentração de 1000mg de vitamina C/kg foi a mais eficiente no controle do aumento da glicemia, 94,6mg/dl imediatamente após a simulação e 74,4mg/dl 12 horas após a simulação. Para a concentração de 500mg de vitamina C/kg foram observados os níveis de 91,4mg/dl imediatamente após a simulação e 103,8mg/dl 12 horas após a simulação. Os valores do hematócrito não apresentaram variação significativa (P>0,05). A suplementação com 1000mg de vitamina C/kg por 14 dias anteriores ao transporte pode ser utilizada de forma profilática em alevinos de tilápia nilótica para amenizar o aumento da glicemia relacionado ao estresse.Palavras-chave: peixe, Oreochromis niloticus, glicose, vitamina C, hematócrito ABSTRACT

This study investigated the effect of different proportions of dietary docosahexaenoic acid (DHA) and arachidonic acid (ARA) on the growth, survival and stress response of curimba (Prochilodus lineatus Valenciennes) larvae, an omnivorous freshwater species, fed on enriched Artemia. Six different experimental emulsions were formulated to have two levels of ARA (A-0.5 and A-1.0), two levels of DHA (D-0.5 and D-1.0) two combinations of ARA and DHA (AD-3:1 and AD-1:3). There were no significant effects of treatments on curimba standard length and survival at the end of the experiment. The results showed a negative correlation between dietary DHA and whole-body cortisol after 60 s of air exposure. The resting concentration of cortisol was not affected by the diets (p = .424). After air exposure, all treatments except for D-1.0 (p = .137) and D-0.5 (p = .545) exhibited a marked cortisol rise. These results showed that DHA supplementation can have an attenuating effect on cortisol response after air exposure. K E Y W O R D Scortisol, enrichment, freshwater fish, highly unsaturated fatty acids

Resumo -O objetivo deste trabalho foi avaliar o efeito e a interação entre a suplementação de palmitato de ascorbil e acetato de tocoferol, na alimentação de larvas de dourado (Salminus brasiliensis), durante o seu desenvolvimento inicial. Foi utilizado o delineamento experimental inteiramente ao acaso, com parcelas subdivididas: nas parcelas, em arranjo fatorial (2x3) com seis rações constituídas pela combinação de duas concentrações de acetato de tocoferol (0 e 250 mg kg -1 ) e três concentrações de palmitato de ascorbil (0, 100 e 1.000 mg kg -1 ); e, nas subparcelas, com dois períodos de coletas (5 e 15 dias de alimentação). Nas larvas, foram determinadas as concentrações do palmitato de ascorbil, ácido ascórbico e ácido deidroascórbico, comprimento total, peso e altura da cabeça. O palmitato de ascorbil proporcionou aumento no comprimento total e no peso das larvas após 15 dias de alimentação. Foi observada, quanto à altura de cabeça, diferença entre as três dosagens de palmitato de ascorbil testadas. A suplementação de palmitato de ascorbil aumentou todas as concentrações de vitamina C, e apesar de a vitamina E não ter infl uenciado as medidas de desempenho, ela atuou como pró-oxidante metabólico o que aumentou o ácido deidroascórbico.Termos para indexação: Salminus brasiliensis, ácido deidroascórbico, vitamina C, vitamina E. Ascorbyl palmitate and tocopherol acetate as metabolic antioxidants in dourado larvaeAbstract -The objective of this work was to evaluate the effect and interaction between supplementation of tocopherol acetate and ascorbyl palmitate, in the diet of dourado larvae (Salminus brasiliensis), during its initial development. The experimental design was completely randomized in split plot, as follows: in the plot, a factorial arrangement (2x3) with six diets, constituted by the combination between two concentrations of tocopherol acetate (0 and 250 mg kg -1 ) and three concentrations of ascorbyl palmitate (0, 100 and 1,000 mg kg -1 ); and in the subplot, with two periods of sampling (5 and 15 days of feeding). In the larvae, determinations were performed for the concentrations of the ascorbyl palmitate, ascorbic acid and dehydroascorbic acid, total length, weight and height of the head. Ascorbyl palmitate provided an increase in the total length and in the weight of the larvae after 15 days of feeding. For head height, differences were observed among the three doses of tested ascorbyl palmitate. The supplementation of ascorbyl palmitate increased the vitamin C concentrations. Although vitamin E has not infl uenced the development sizes, it acted as a metabolic pro-oxidant, which increased the dehydroascorbic acid.