RESUMO -Foram realizados dois experimentos com o objetivo de definir uma dieta referência para estudos de exigências nutricionais em Piaractus brachypomus. No primeiro experimento, foram testadas quatro dietas com ingredientes semipurificados (H-440 com 47% PB, C-102 com 41% PB, NRC com 37% PB e IALL-1 com 32% de PB) e uma dieta controle (32% de PB) com ingredientes comuns. No segundo experimento, foi usada a dieta IALL-1, como base para a formulação de três dietas experimentais. A dieta 2 foi suplementada com vitamina C e uma pré-mistura de macrominerais, enquanto na dieta 3 o óleo vegetal foi substituído por óleo de peixe. O ganho de peso foi usado como critério básico para medir os efeitos das dietas, sendo também considerados consumo de alimento, taxa específica de crescimento (SGR), conversão alimentar aparente (FCR), eficiência de utilização da proteína (PER) e retenção de proteína (%PPV) e de energia (%RE). Entre as dietas semipurificadas, o melhor desempenho de crescimento e de utilização dos nutrientes foi observado para as dietas NRC e IALL-1, que não diferiram entre si. No segundo experimento, o grupo de peixes alimentados com a dieta 2 apresentou crescimento 42% maior que o observado com as dietas sem suplementação. As outras variáveis analisadas, FCR, SGR, PER e %PPV, também foram significativamente melhoradas. Os resultados em conjunto indicam que a dieta IALL-1 suplementada com macrominerais e vitamina C pode ser considerada adequada como dieta referência semipurificada para estudos de nutrição de Piaractus brachypomus.Palavras-chave: dieta referência, nutrição de peixes, peixe de água doce, pirapitinga, Piaractus brachypomus Studies for Composition of Semipurified Reference Diet for Nutritional Requirements Evaluation of Juvenile Pirapitinga Piaractus brachypomus (Cuvier, 1818)ABSTRACT -Two trial experiments were conducted to determine a reference diet for nutrient requirement studies of Piaractus brachypomus. In the 1st experiment four diets elaborated with purified ingredients (H-440 with 47% PB, C-102 with 41% PB, NRC, with 37% PB and IALL-1 with 32% of PB) and a diet control (32% of PB) with common ingredients, were tested. In the 2 nd experiment the diet IALL-1 was used as base for the formulation of three experimental diets. Diet 2 contained vitamin C and macrominerals premix supplement, while in diet 3 vegetable oil was substituted by fish oil. Weight gain, taking also into account the relative food intake, specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), protein retention (%PPV) and energy retention (%RE), was used as the basic approach for measuring the effects of the diets. The best growth performance and nutrient use among semipurified diets was observed for diets NRC and IALL-1. In the 2 nd experiment, fish fed diet 2 presented a growth (42%) greater than those fed non supplemented diets. Other analyzed variables FCR, SGR, PER and %PPV were also significantly improved. The added results indicate that macro minerals and vitamin C supplemented-die...

A growth experiment was conducted to determine the optimal dietary protein requirement for juvenile cachama, Piaractus brachypom us. Six semi-purified isoenergetic experimental diets using casein and gelatin as protein sources were formulated to contain graded levels of protein (16, 20, 24, 28, 32 and 36%)

The effects of diets with three contents of carbohydrates and lipids were evaluated on the growing performance of cachama Piaractus brachypomus juveniles (initial weight 7.8 ± 0.49 g). The experiments were performed a 3 9 3 factorial design (200, 280 and 360 g of carbohydrates and 40, 80 and 120 g of lipids kg À1 ). Protein content was kept constant in 320 g kg À1 and digestible energy between 11.3 and 16.1 MJ kg À1 . Simple effects and interaction of factors on growth performance varied significantly (P < 0.05) indicating dependence among them. The maximum weight gain was observed in fish fed 200 and 280 g kg À1 carbohydrates and 40 g kg À1 lipids. Increase of lipids from 80 to 120 g kg À1 reduced growth significantly. Protein efficiency rate and percentages of protein retention and energy were positively correlated with carbohydrate levels and no significant differences (P > 0.05) were observed with the lipid levels. Results indicate that cachama utilizes carbohydrates as energy source more efficiently than lipids; likewise, lipid levels over 40 g kg À1 depress growth at any carbohydrates level.

The yamúBrycon siebenthalae is an endemic fish of the Orinoco river basin, but wild stocks are decreasing because of the disruption of their habitat. We evaluated a protocol for the cryopreservation of yamú sperm to contribute to the preservation of this endangered genetic resource. Milt was mixed with a cryoprotectant medium (5.5% glucose, 12% egg yolk, and 5%, 10%, or 15% dimethyl sulfoxide ‐ DMSO) in a ratio 1:4 (milt:medium), stored in 0.5‐mL French straws, frozen in nitrogen liquid vapor (‐76 C), then immersed and stored in liquid nitrogen for 10 d or 12 mo. Motility of thawed spermatozoa was higher (P < 0.001) in 10% DMSO medium than 5% DMSO or 15% DMSO mediums; but lower than the control (P < 0.001). With sperm cryopreserved, the highest level of fertilization was achieved with 10% DMSO (P < 0.001) after 10 d or 12 mo of cryopreservation. Fertilization of eggs inseminated with 6.4 × 109 spermatozoa per g of eggs was higher (P <0.05) than with 1.6 × 109 spermatozoa per g of eggs. There was no difference (P > 0.05) in fertilization between insemination doses of 3.2 × 109 and 6.4 × 109 spermatozoa per g of eggs. Cryopreservation of yamu milt can be performed successfully with a simple medium combined with 10% of DMSO as cryoprotectant. The highest level of fertility was achieved using between 3 × 109 and 6 × 109 spermatozoa per g of fresh eggs.

Fundamentos de la tecnología biofloc (BFT). Una alternativa para la piscicultura en Colombia. Una revisión 77 ARTÍCULO DE REVISIÓN/REVIEW ARTICLE Fundamentos de la tecnología biofloc (BFT).Una alternativa para la piscicultura en Colombia. Una revisión Fundamentals of bioflocs technology (BFT).An alternative for fish farming in Colombia. A review. Fundamentos da bioflocos tecnologia (BFT ResumenLos sistemas convencionales de producción piscícola en Colombia empiezan a descender principalmente por la necesidad de grandes cantidades de agua cada vez más escasa, aumento de la contaminación de los afluentes de descargue, aumento del costo de los alimentos con gran desperdicio de los mismos y otros factores ambientales adversos como sequías en grandes áreas del territorio e irregulares volúmenes de producción por unidad de área o volumen. Por lo anterior la búsqueda de nuevas posibilidades de producción piscícola que sean amigables con el ambiente, incluyentes socialmente y rentables son cada vez más apremiantes. Una de las alternativas que empiezan a cautivar el interés de los piscicultores es el sistema de producción súper-intensiva con tecnología biofloc (BFT), la cual se sustenta en aprovechar la acumulación de residuos de los alimentos, materia orgánica y compuestos inorgánicos tóxicos a través de microorganismos presentes en los medios acuáticos, dando condiciones de dominancia a comunidades autótrofas y heterótrofas, resolviendo sustancialmente los problemas de saturación de nutrientes a partir de su reciclaje, en este sentido el objetivo de la presente revisión es presentar los fundamentos básicos de la BFT, como una alternativa de producción piscícola.Palabras clave: microorganismos, tecnología biofloc, piscicultura, nutrientes. AbstractConventional systems for fish production in Colombia begin to decline mainly due to the need for large quantities of increasingly scarce water, increasing pollution of the tributaries of discharge, increased cost of food with great waste of these and other factors adverse environmental and droughts in large areas of territory and different volumes of production per unit of area or volume. Therefore the searches for new potential for fish production is environmentally friendly, socially inclusive and profitable are becoming more pressing. One of the alternatives that are beginning to captivate the interest of farmers is the system of super intensive production bioflocs technology (BFT), which is based on the accumulation of waste