-The study evaluated the replacement of bovine heart by gelatin in the feed training of carnivorous fish, using giant trahira (Hoplias lacerdae) as an experimental model. A completely randomized design with four treatments and five repetitions was employed. The treatments were composed of wet ingredients beef heart (control), gelatin diluted in water, gelatin diluted in beef heart broth, and gelatin diluted in water mixed with fish meal. The fish (3.22±0.03 cm and 0.57±0.01 g) were conditioned to accept industrialized diets by the technique of gradual feed ingredients transition in the diet. Gains in weight and length, efficiency of feed training, specific growth rate, cannibalism, mortality and survival rates were evaluated. There was significant difference in weight and length gains and specific growth rate, whereby the use of bovine heart gave the best results. Greater efficiency of feed training was observed for fish fed diets containing beef heart and gelatin diluted in water mixed with fish meal. The high survival rates and the absence of significant differences among treatments for rates of cannibalism, mortality and survival indicate the feasibility of using gelatin as a moist ingredient in the feed training of carnivorous fish.

This study aimed to evaluate the effect of different proportions of soybean and linseed oil to replace fish oil in diets for female lambari (Astyanax altiparanae). A completely randomized design with seven treatments and five replicates was used. The treatments consisted of a diet containing fish oil and six diets containing different proportions of soybean oil (S) and linseed oil (L), 10S/0L, 8S/2L, 6S/4L, 4S/6L, 2S/8L and 0S/10L. The fish that received the highest proportion of linseed oil (0S/10L) had the lowest crude lipid in their carcasses. The highest linolenic acid (18:3n3) concentrations were detected in the carcasses of fish fed diets with high proportions of linseed oil (4S/6L, 2S/8L, and 0S/10L). The highest n6/n3 ratios corresponded to the carcasses of fish fed diets containing the lowest proportions of linseed oil (10S/0L and 8S/2L). The highest levels of 20:5n3 (eicosapentaenoic acid [EPA]), 22:6n3 (docosahexaenoic acid [DHA]) and EPA+DHA occurred in fish fed diets containing fish oil. Among the fish that received diets with vegetable oils, the EPA+DHA was higher in the fish of the treatments 4S/6L, 2S/8L and 0S/10L. Diets supplemented with a 4S/6L proportion provide adequate deposition of the n3 fatty acids series in the lambari carcass.

-The objective of the present study was to evaluate the protein requirement of juvenile Trichogaster lalius, blue variety. The experimental design was of randomised blocks (B1 = initial weight of 1.04±0.05 g and B2 = 1.36±0.02 g), with two replicates within each block and five treatments (230, 270, 310, 350 and 390 g CP/kg diet). The fish were fed to satiation, three times a day for 90 days. The study evaluated: survival rate, weight gain, final length, feed intake, feed conversion ratio, protein efficiency ratio, specific growth rate and condition factor. There was a linear effect of dietary protein levels for protein efficiency ratio, specific growth rate (positive linear effect) and feed conversion ratio (negative linear effect). For weight gain, final length, feed intake and condition factor a quadratic effect of dietary protein levels was observed, with estimated values of 409.8, 366.2, 317.4 and 365.0 g CP/kg diet, to improve their performance parameters. Analysis of growth based on the length of the fish shows that 366.2 g of CP/kg diet meets the protein requirement of juvenile Trichogaster lalius, blue variety.

Two experiments were performed. The first aimed to assess the tolerance of fingerlings Astyanax altiparanae to water salinity. Fish were exposed to salinity of 0, 3, 6, 9, 12 or 15 g NaCl L -1 for 96 hours. The fish mortality was 0%, in the levels of 0, 3 and 6 g L -1 ; 75% in the level of 9 g L -1 and 100% at 12 and 15 g L -1 of common salt. The second experiment aimed to assess the parameters of water quality, mortality and blood glucose during transport. For this, A. altiparanae were stored in plastic bags at 22, 30 and 37 g of fish L -1 stocking densities and salinity of 0, 3, 6 and 9 g L -1 , for. Fish showed similar mortality levels in the different salinities and stocking densities. The increase in fish density reduced the dissolved oxygen levels and salinity decreased the pH. The blood glucose levels were higher in those fish with 0 g L -1 salinity and higher stocking densities. The addition of salt to the water reduces the stress responses of A. altiparanae during transport.Transporte de Astyanax altiparanae Garutti and Britski, 2000 em água salinizada RESUMO. Foram realizados dois experimentos. O primeiro teve o objetivo de avaliar a tolerância de alevinos de Astyanax altiparanae a salinidade da água. Os peixes foram submetidos às salinidades de 0, 3, 6, 9, 12 ou 15 g de NaCl L -1 durante 96 horas. A mortalidade dos peixes foi de 0%, nos níveis de 0, 3 e 6 g L -1 ; de 75% no nível de 9 g L -1 e de 100% em 12 e 15 g L -1 de NaCl. No segundo experimento, objetivou-se avaliar os parâmetros de qualidade de água, mortalidade e a glicose sanguínea durante o transporte. Para isso, A. altiparanae foram estocados em sacos plásticos nas densidades de 22, 30 e 37 g de peixe L -1 e salinidades de 0, 3, 6 e 9 g de NaCl L -1 . A mortalidade foi semelhante nas diferentes salinidades e densidades de estocagem. O aumento da densidade de peixes reduziu o nível de oxigênio dissolvido e a salinidade da água reduziu o pH. Os níveis de glicose sanguínea foram maiores nos peixes expostos a salinidade de 0 g L -1 e nas maiores densidades de estocagem. A adição de sal na água reduz as respostas de estresse em A. altiparanae durante o transporte.Palavras-chave: densidade, estresse, glicose, oxigênio, sal comum.

No abstract

The aim of this study was to evaluate commercial gelatin in the total replacement of bovine heart in feed training of "pacamã" Lophiosilurus alexandri in different water salinities. A completely randomized experimental design, in a 2 × 3 factorial arrangement, was performed using two types of moist ingredients (bovine heart and gelatin) and three water salinities (0.0; 2.0 and 4.0 g of salt L -1 ) with three replications.Juveniles (2.39 ± 0.08 cm standard length and 0.20 ± 0.03 g of weight) were conditioned to accept commercial diets by the technique of the gradual transition of ingredients. At the end of 36 days no differences were observed to weight gain, length gain and specific growth rate. The feed training efficiency was better (P < 0.05) with the gelatin use, 100.0%. There was a negative effect of salinity on the survival rate and management efficiency in the concentration of 4 g of salt L -1 , with values of 58.6 ± 12.0 % and 58.0 ± 12.0 %, respectively. Lophiosilurus alexandri juveniles could be feed-trained to accept commercial diets with gelatin in the total replacement of bovine heart in freshwater or salinity of 2 g of salt L -1 .

Seaweeds have many uses in industry and agriculture and many species have potential for integrated multi-trophic aquaculture (IMTA), since they are efficient in removing nutrients from water. The efficiency of Ulva flexuosa, U. fasciata and Gracilaria birdiae in removing nutrients from enriched water and their productive performance in outdoor tanks were quantified. These seaweeds (50 g; n = 5) were grown in tanks containing 50 L of eutrophic seawater, with a salinity of 30, a temperature of 28.5 ± 2.8 °C, an irradiance of 547 ± 458 μmol photons m -2 s -1 and aeration. The nutrients levels were recorded daily and when total nitrogen removal was detected, the biomass was measured. After five days of cultivation, more than 98% of NH3 (H = 1.1; P = 0.56) and NO3 -(H = 2.7; P = 0.25) and 62.1% of PO4 3-(H = 0.0; P = 0.90) had been removed from the tanks. However, the mean daily growth rate (4.5 ± 2.5% day -1 ) and productivity (3.5 ± 1.9 g m -2 day -1 ) of U. fasciata and G. birdiae were higher than U. flexuosa (-13.6 ± 7.7% day -1 ; -6.24 ± 2.8 g m -2 day -1 ; P<0.01), demonstrating that microalga contamination by this species promoted high removal efficiency in the tanks, but a low productive performance. Based on these results, U. fasciata and G. birdiae show a greater potential for use in IMTA to improve water quality and produce biomass.Keywords: Gracilaria birdiae; productivity; daily growth rate; nutrient removal; Ulva fasciata; Ulva flexuosa EFICIÊNCIA BIOFILTRADORA E DESEMPENHO PRODUTIVO DE MACROALGAS COMPOTENCIAL PARA AQUICULTURA MULTI-TRÓFICA INTEGRADA (AMTI) RESUMOAs macroalgas são utilizadas em diversos setores industriais e agrícolas. Além disso, muitas espécies apresentam potencial para aquicultura multitrófica integrada (AMTI), pois são eficientes na remoção de nutrientes da água. A eficiência biofiltradora e desempenho produtivo das macroalgas Ulva flexuosa, U. fasciata e Gracilaria birdiae e foram quantificados em tanques outdoor. As algas (50 g; n = 5) foram cultivadas em tanques de 50 L, com água eutrofizada, salinidade 30 e temperatura média 28,3 °C. Os nutrientes foram monitorados diariamente e a biomassa foi mensurada assim que detectada a extinção do nitrogênio. Após cinco dias de cultivo, mais de 98% de NH3 (H = 1,1; P = 0,56) e de NO3 -(H = 2,7; P = 0,25) e 62,1% de PO4 3-(H = 0,0; P = 0,9) foram removidos dos tanques. Contudo, a taxa de crescimento (% dia -1 ) e a produtividade (g m -2 dia -1 ) de U. fasciata e de G. birdiae (4,5 ± 2,5% dia -1 ; 3,5 ± 1,9 g m -2 dia -1 ) foram superiores às de U. flexuosa (13,6 ± 7,7% dia -1 ; 6,2 ± 2,8; P<0,01), cuja contaminação por microalgas contribuiu para elevada eficiência de retirada nos tanques desta espécie, mas baixo desempenho produtivo. Desta forma, U. fasciata e G. birdiae foram indicadas para AMTI tanto para a manutenção da qualidade da água quanto para aproveitamento de biomassa.

The aim of this study was to evaluate the dietary crude protein requirements of juvenile Betta splendens. Isocaloric diets were used with six levels (27, 31, 35, 39, 43 e 47%) of crude protein (CP) in entirely randomised design with four repetitions. Fish with an average weight of 0.11 ± 0.02g were fed three times a day for 30 days. At the end of the experiment were evaluated: survival rate (SR); weight gain (WG); feed intake (FI); protein intake (PI); feed conversion (FC); protein efficiency ratio (PER); and specific growth rate (SGR). For FI, FC and PER, a negative linear effect of dietary CP levels was observed (p < 0.05). A quadratic effect of dietary CP levels for SR, WG and SGR was also observed and the estimated values which maximise the respective parameters were 30.95, 33.13 and 29.55% of CP. Thus, we concluded that the requirement for protein for juvenile Betta splendens is between 30 and 33% CP.