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This study evaluated the effects of live prey concentration (nauplii of Artemia sp.), water salinity, and weaning age on survival, growth, and stress resistance rate (Rs) of Piaractus brachypomus under larviculture in a recirculating aquaculture system (RAS). Larvae aged 6 days post-hatching (1.64 ± 0.11 mg) were distributed in 28-L tanks (five larvae L-1), in two RASs. The experiment was carried in a 2 × 2 × 2 factorial arrangement, as follows: two feeding strategies (sudden transition from live food to commercial food after 10 (FT10) and 20 (FT20) days of larviculture with Artemia); two daily initial prey concentrations (P350 = 350 and P700 = 700 nauplii larva-1, these being increased every 5 days); and two water salinities (S0 = fresh water and S2 = 2 g of salt L-1). Weight (W), total length (TL), and daily specific growth rate (SGR) were evaluated after 10, 20, 30, and 40 days of larviculture. After 40 days of larviculture, survival was evaluated and a test of air exposure was performed to determine stress resistance rate (Rs). Noteworthy results during this period are the lowest specific daily growth rate (SGR) after weaning for FT10 and the best growth results for S2 and P700. After 40 days, weight (W) and total length (TL) showed effects of P, FT, and S with higher values for P700, FT20, and S2 (P < 0.05). The interaction P × FT × S also had effects on survival and Rs at the end of the experiment, with higher survival and Rs for P700FT20S2 (P < 0.05). Larviculture of P. brachypomus in RAS, in association with the three managements-live prey concentration P700, salinity S2, and age at feed transition FT20-promotes maximization of survival, growth, and stress resistance rate of the animals. The larviculture of P. brachypomus in RAS must be carried out with an initial concentration of live prey of 700 nauplii larva-1, at a salinity of 2 g of salt L-1 and with the feeding transition starting in 20 days of larviculture, for maximization intensive larviculture of this species.

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Recently, the large migratory fishes of the family Serrasalmidae (Piaractus brachypomus and P. orinoquensis) were described as restricted to the Orinoco and Amazon basins. Both species provide important ecosystem services. They also are an important fisheries resource, which has caused that their populations have decreased in recent years. National fisheries policies still consider both species as one, which leads to inefficiencies in their management and conservation. The aim of this study was to genetically characterize these two species, using microsatellite and mitochondrial markers, and discuss the implication of these results for conservation and management. We found that both species have moderate genetic diversity and varied patterns of genetic distribution in the fluvial landscape. Piaractus brachypomus presented genetic diversity of A=6.5; He=0.72; Ho=0.67; H=1.000; á´«=0.0092, three management units related to the evolutionary process of the Amazon basin and the effective sizes of local populations were smaller compared to P. orinoquensis, which presented genetic diversity of A=6.1; He=0.66; Ho=0.55; H=0.968; á´«=0.010 and comprises only one management unit. These results demonstrate the need to design management policies that focus on species and geographically restricted populations.

Recientemente, los grandes peces migratorios Serrasalmidae (Piaractus brachypomus y P. orinoquensis) fueron diferenciados en las cuencas del Orinoco y Amazonas. Ambas especies brindan importantes servicios ecosistémicos, entre ellos la pesca para la dieta humana, lo que ha provocado que sus poblaciones hayan disminuido en los últimos años. Las políticas pesqueras nacionales aún consideran a ambas especies como una sola, lo que conduce a ineficiencias en su gestión y conservación. El objetivo de este estudio fue caracterizar genéticamente estas dos especies de Piaractus, usando marcadores microsatélites y mitocondriales, y discutir la implicación de estos resultados para la conservación y el manejo. Encontramos que ambas especies tienen una diversidad genética moderada y patrones variados de distribución genética en el paisaje fluvial. Piaractus brachypomus presentó diversidad genética de A=6.5; He=0.72; Ho=0.67; H=1.000; á´«=0.0092, tres unidades de manejo relacionadas con el proceso evolutivo de la cuenca Amazónica y los tamaños efectivos de las poblaciones locales fueron menores en comparación con P. orinoquensis, que presentó diversidad genética de A=6.1; He=0.66; Ho=0.55; H=0.968; á´«=0,010 y comprende una sola unidad de gestión. Estos resultados demuestran la necesidad de diseñar políticas de manejo que se enfoquen en especies y poblaciones geográficamente restringidas.

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RESUMEN En la industria acuícola, se vienen desarrollando acciones encaminadas a buscar fuentes proteicas alternativas palatables y de alto valor biológico para reemplazar las fuentes convencionales. Debido al potencial nutricional de los subproductos animales, se han adoptado tecnologías para su uso, como las técnicas de bioconversión por hidrólisis enzimática. En consecuencia, el objetivo de este estudio fue obtener y evaluar un concentrado de proteína hidrolizada de residuos animales (CPHRA) como alternativa en dietas para Piaractus brachypomus. Las vísceras de los subproductos avícolas se evaluaron utilizando ácido fórmico y vísceras de trucha al 20% para promover la hidrólisis enzimática a un pH más bajo (pH 3,66). El producto resultante se utilizó en la formulación de dietas para determinar coeficiente de digestibilidad aparente (CDA) de energía y nutrientes, utilizando una dieta control () y tres dietas con inclusión de 10%, 20% y 30% de CPHRA (T1, T2 y T3). Se alimentaron por triplicado ciento veinte juveniles de híbridos de cachama blanca con un peso promedio de 145 ± 3,0 g. La CPHRA presentó alto contenido proteico y se evidenciaron diferencias significativas (p < 0,05) para los CDA de materia seca, proteína bruta, grasa bruta, energía bruta y absorción de cenizas, calcio y fósforo. Los CDA de nutrientes y energía estaban por encima del 80%. En consecuencia, el concentrado de proteína hidrolizada de los desechos de aves de corral tiene un gran potencial como alternativa proteica y energética de alto valor nutricional en la alimentación de los peces.

ABSTRACT The aquaculture industry aims to find new strategies to replace fishmeal in formulated diet-sources with high attraction and palatability and high biological value to replace conventional sources. Due to the nutritional potential of animal by-products, technologies have been adopted for their use, such as bioconversion techniques by enzymatic hydrolysis. Consequently, the objective of this study was obtaining and evaluating a hydrolyzed protein concentrate of animal waste (CPHRA, by its Spanish acronym) in diets for Piaractus brachypomus. Viscera from poultry by-products was evaluated by using formic acid and a 20% trout viscera to promote the catalyst at lower pH (3,66). The resulting product was used in feed formulation to determine the Apparent Digestibility Coefficient (ADC) of energy and nutrients, using a control diet (T0) and three diets with 10%, 20%, and 30% CPHRA (T1, T2 y T3). One hundred and twenty juveniles of hybrids of cachama blanca with an average weight of 145 ± 3,0 g were fed in triplicate groups. The CPHRA presented high protein content and significant differences (p < 0,05) were evidenced for the ADCs of dry matter, crude protein, crude fat, crude energy, and ash absorption, calcium and phosphorus. The ADCs for nutrients and energy were above 80%. Accordingly, the hydrolyzed protein concentrate from poultry waste has great potential as a protein and energy alternative of high nutritional value in fish feeding.

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RESUMEN Los temas de la acuicultura en los que se requiere innovación e investigación están orientados al mejoramiento y al conocimiento genético de especies nativas. En este sentido, el presente estudio se concentró en estimar heredabilidades, correlaciones genéticas y fenotípicas para características de crecimiento, canal, calidad y espinas intramusculares derechas (EIMD), en cachama blanca (Piaractus brachypomus). La progenie de 12 hembras y 24 machos por fertilización artificial de una hembra por dos machos, es decir, doce familias de hermanos medios, fueron analizados por medio del paquete estadístico SAS 9.4 (SAS®, 2014). Se asumió un modelo lineal general univariado, con inclusión de los efectos fijos, como factores de entorno, estanque y edad y factores genéticos, como efectos aleatorios. Las heredabilidades, en general, para las variables de crecimiento, mostraron valores de medios a altos; para las variables de la canal presentaron valores bajos a medios; para las variables de calidad fueron bajos y, de particular interés para la EIMD, la magnitud de la estima fue de 0,11 ± 0,15. Las correlaciones estuvieron, generalmente, cercanas a la unidad entre características de crecimiento. Estas fueron significativamente positivas para peso corporal, a 180 días de edad, con la mayoría de variables, a diferencia con las variables de calidad, la correlación para rendimiento en canal con EIMD de -0,99 fue encontrada significativamente negativa. Los resultados del estudio destacan el potencial para mejorar características de crecimiento, de canal y de calidad, a través de la explotación de la variación genética aditiva observada.

ABSTRACT The topics of aquaculture in which innovation and research are required are directed towards the improvement and genetic knowledge of native species. In this sense the present study concentrated on the estimation of heritabilities, genetic and phenotypic correlations for growth, carcass, quality and right intramuscular spines (RIMS) in white cachama (Piaractus brachypomus). The progeny of 12 females and 24 males by artificial fertilization of a female by two males, that is to say twelve half-sib families, were analyzed by means of the statistical package SAS 9.4 (SAS®, 2014), assumed an univariate general linear model with inclusion of Fixed effects such as environmental factors, pond and age as fixed effects and genetic factors as random effects. Heritabilities in general for growth variables showed medium to high values; for carcass variables, presented low to medium values; And for the quality variables were low; For the RIMS the magnitude of the estimate was 0,11 ± 0,15. The correlations were generally close to unity between growth characteristics. These were significantly positive for body weight at 180 days of age with most variables unlike quality variables; the correlation for channel performance with RIMS of -0.99 was found to be significantly negative. The results of the study highlight the potential to improve growth, carcass and quality traits through the exploitation of the additive genetic variation observed in this study.

RESUMEN

Resumen Se utilizaron 177 juveniles de Piaractus brachypomus, mantenidos durante 84 días en dos estanques asignados a dos tratamientos de alimentación: T1: diaria y T2: un día sí y un día no. Se realizaron colectas de sangre los días 1, 28, 42, 56, 70 y 84 de 7 animales por tratamiento para determinación de hematocrito, hemoglobina, proteína, glucosa, lactato, triglicéridos, colesterol, cortisol e insulina. Los animales fueron pesados, medidos y sacrificados para cálculo de índices hepatosomático (IHS), viscerosomático (IVS) y grasa visceral (IGV); al final del ensayo a los animales muestreados se les realizó análisis proximal y de energía en filete. El hematocrito presentó diferencias significativas entre tratamientos los días 56 y 84, siendo superior en T1 el día 56 e inferior el día 84. Excepto los días 1 y 42, en los que la hemoglobina fue superior en T1, no hubo diferencias significativas entre tratamientos. Para glucosa, insulina y lactato hubo diferencias significativas el día 28: las dos primeras fueron superiores en T1, mientras que el lactato lo fue en T2. La proteína aumentó significativamente en T1 el día 42, nivel que se mantuvo el día 56, disminuyendo el día 70 y manteniéndose así hasta el día 84. Para triglicéridos, colesterol y cortisol no hubo diferencias significativas entre tratamientos en ninguna de las colectas. Además, se presentaron diferencias significativas en peso los días 42 y 70, y en longitud el día 42, no existiendo diferencias entre tratamientos al final del ensayo. Para IHS e IVS hubo diferencias significativas el día 84, siendo superiores en T1, sin diferencias para IGV. La sobrevivencia fue 100% en ambos tratamientos. El análisis proximal y la energía del filete no presentaron diferencias entre tratamientos. Se concluye que la restricción alimenticia del 50% en el esquema alternado utilizado, no afectó la condición fisiológica de los animales, pues no se evidenció ningún daño metabólico importante, ni cambios en la composición del producto final.

Abstract 177 juveniles of Piaractus brachypomus were kept during 84 days in two ponds. Each group was assigned one of the following treatments: T1: fed every day, and T2: fed every other day. Blood samples from 7 animals of each treatment were taken on days 1, 28, 42, 56, 70, and 84 to determine hematocrit, hemoglobin, glucose, lactate, protein, triglycerides, cholesterol, cortisol, and insulin. Fish were weighted, measured, and sacrificed to remove the liver, viscera, and visceral fat to calculate the hepatosomatic index (HSI), viscerosomatic index (VSI), and visceral fat index (VFI). At the end of the trial, the group of sampled animals were filleted to do the energy and proximal analysis. There were significant differences in hematocrit between treatments, on days 56 and 84, they were higher in T1 on day 56, and lower in T1 on day 84. On days 1 and 42, hemoglobin was higher in T1, there were no significant differences among treatments. There were significant differences in glucose, insulin and lactate on day 28; the first two were higher in T1, while lactate was higher in T2. Protein significantly increased in T1 on day 42, and was the same on day 56, then decreased on day 70, and remained stable until day 84. There were no significant differences between treatments in triglycerides, cholesterol, and cortisol during any of the sample times. There were significant differences in the weight on days 42 and 70, and in length on day 42, but there were no significant differences between treatments at the end of the test. There were significant differences in IHS and IVS on day 84, they were higher in T1. There were no differences in IGV. Survival was 100% in both treatments. There were no differences in energy and proximal analysis of the fillets between the treatments. We can conclude that a 50% food restriction in the alternated scheme did not affect the physiological condition of the animals because there was not any significant metabolic damage or changes in the composition of the final product.

Resumo Juvenis de Piaractus brachypomus (177), foram mantidos por 84 dias em dois viveiros sendo alimentados assim: T1: alimentação todos os dias e T2: alimentação a cada dois dias. Realizaram-se coletas de sangue nos dias 1, 28, 42, 56, 70 e 84 de sete animais por tratamento para determinação do hematócrito, hemoglobina, glicose, lactato, proteína, triglicerídeos, colesterol, cortisol e insulina. Também foram pesados, medidos e sacrificados, para o cálculo dos índices hepatossomático (IHS), viscerossomático (IVS) e de gordura visceral (IGV). No hematócrito houve diferenças entre os tratamentos nos dias 56 e 84, sendo maior no T1 no dia 56 e menor no dia 84. Com exceção dos dias 1 e 42, em que a hemoglobina foi maior em T1, não houve diferenças entre os tratamentos. Para glicose, insulina e lactato, houve diferenças no dia 28. As duas primeiras foram maiores em T1, enquanto que o lactato foi maior em T2. A proteína aumentou em T1 no dia 42 y esteve alta até o dia 56. Porém, diminuiu no dia 70 e permaneceu baixa até o final. Para triglicerídeos, colesterol e cortisol não houve diferenças entre os tratamentos em nenhum dos tempos de coleta. Além disso, houve diferenças em peso nos dias 42 e 70 e em comprimento no dia 42. Porém, não houve diferenças no final do ensaio. Para IHS e IVS houve diferenças no dia 84, sendo maiores em T1. O IGV não apresentou diferenças no final do ensaio. A sobrevivência foi de 100% em ambos os tratamentos. As análises proximais e de energia não apresentaram diferenças entre os tratamentos. Pode-se concluir que a restrição alimentar de 50%, não afetou o estado fisiológico dos animais, devido a que nenhum dano metabólico importante foi evidente, nem alterações na composição do produto final.

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Resumen El cultivo en biofloc es una alternativa de producción en la cual se utiliza proteína bacteriana de alto valor biológico como posible suplemento alimenticio y como estrategia para ahorrar recursos y mantener la calidad de agua dentro de los parámetros exigidos por la especie. Durante 60 días se comparó el desempeño productivo de juveniles de cachama blanca Piaractus brachypomus cultivados en sistema intensivo con renovación de agua (T1) y con tecnología biofloc (T2). T1 recibió recambios de agua del 50% semanal y limpieza de fondo dos veces por semana; T2 en sistema biofloc (BFT) con adición de melaza en una relación carbono:nitrógeno de 15:1. Ambos tratamientos recibieron alimento balanceado con 24% de proteína de origen vegetal suministrado hasta saciedad aparente cuatro veces/día. Fueron empleados 480 alevinos, con peso promedio de 0,8 ± 0,33 g y talla de 3,0 ± 0,4 cm. Cada 15 días se determinó peso y longitud estándar (LE), ganancia diaria de peso (GDP), tasa específica de crecimiento en peso (TEC), biomasa (B), factor de conversión alimenticia (FCA), sobrevivencia (S) y factor de condición (K). Se midió oxígeno disuelto (OD), temperatura (T°), pH, salinidad (ppT) y sólidos suspendidos totales (SST) dos veces al día. Semanalmente se determinó nitrógeno amoniacal total (NAT), nitrito, nitrato, alcalinidad y dureza. El desempeño productivo no fue diferente entre los tratamientos (P>0,05). Con la tecnología biofloc es posible manejar las mismas densidades de peces y mantener rendimientos productivos adecuados, similares a los de un sistema productivo intensivo aunque optimizando el uso del recurso hídrico.

Abstract Biofloc cultures are an interesting alternative in which bacterial protein with high biological value is used as a possible food supplement and as part of a strategy to keep water quality within the parameters required by a given species. The production performance of juveniles of white cachama Piaractus brachypomus was compared for 60 days. The fish were reared in two systems: one was intensive and had water renewal (T1), while the other had biofloc technology (T2).T1 had 50% of its water changed weekly and the pond's bottom was cleaned twice per week. In contrast, T2 was a biofloc system (BFT) with added molasses in a carbon:nitrogen ratio of 15:1. In both treatments the fish were fed to apparent satiety four times per day. The feed was balanced and had 24% of protein of vegetable origin.A total of 480 fingerlings were used, whose average weight and size were 0.8 ± 0.33 and 3.0 ± 0.4 cm, respectively.The following parameters were determined on a fifteen-day basis: weight, standard length (SL), daily weight gain (DWG), specific rate of growth in terms of weight (SGR), biomass (B), feed conversion ratio (FCR), survival rate (S), condition factor (K). Likewise, dissolved oxygen (DO), temperature (T°), pH and salinity (ppT) were measured twice a day. Furthermore, total suspended solids (TSS) and biofloc volume were measured every two days.The total ammonia nitrogen (TAN) and the levels of nitrite, nitrate, alkalinity and hardness were determined weekly. Production performance showed no variations across treatments (P>0.05).The biofloc technology makes it possible to have the same fish densities as those observed in intensive production systems. Likewise, the production performance values are adequate and similar to those of this kind of system, but the water resource is optimized.

Resumo O cultivo com bioflocos é uma alternativa de produção onde é utilizada proteína bacteriana de alto valor biológico como possível suplemento dietário e como estratégia para poupar recursos e manter a qualidade da agua dentro dos parâmetros exigidos pela espécie. Durante 60 dias o desempenho produtivo dos juvenis de pirapitinga criados em sistema intensivo com renovação da água (T1) e com bioflocos foi comparado (T2) sem renovação, só repor à agua perdida pela evaporação. Os peixes de T1 receberam renovações de água de 50% semanais e, limpeza do fundo duas vezes na semana. Os peixes de T2 estiveram em sistema com bioflocos. Com adição de melaço numa razão carbono: nitrogênio de 15:1. A ração fornecida tinha 24% de proteína vegetal e foi ministrada até saciedade quatro vezes ao dia. Foram utilizados 480 alevinos com peso médio de 0,8 ± 0,33 g e tamanho de 3,0 ± 0,4 cm. Cada 15 dias foi determinado peso e comprimento padrão, ganho de peso diário (GDP), taxa específica de crescimento (TEC), biomassa (B), conversão alimentar, sobrevivência (S) e fator de condição (K). Foi medido oxigênio dissolvido (OD), temperatura, pH, salinidade (ppT) e sólidos suspendidos totais (SST) duas vezes ao dia. Semanalmente foi determinado nitrogênio amoniacal total (NAT), nitrito, nitrato, alcalinidade e dureza. Não foram observadas diferenças no desempenho produtivo entre os tratamentos (P>0,05). Com a aplicação da tecnologia com bioflocos é possível utilizar as mesmas densidades de peixes e manter o desempenho produtivo ótimo, semelhantes aos de um sistema de produção intensiva embora otimizando a utilização da agua.

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El objetivo general del trabajo fue evaluar el efecto de la restricción de alimento sobre el desempeño productivo y fisiológico de juveniles de cachama blanca y sobre su conte nido muscular de proteína y energía. En cuanto al diseño experimental, este fue com pletamente al azar, con cuatro tratamientos y cuatro repeticiones, cada una con cuatro individuos. Se seleccionaron 64 individuos con 58,40 ± 6,56 g de peso (P) y 14,65± 0,75 cm de longitud total (LT), distribuidos aleatoriamente en 16 acuarios y sometidos durante ocho semanas a los siguientes tratamientos: de control (T0): alimentación dia ria; tratamiento 1 (T1): un día de ayuno y uno de alimentación; tratamiento 2 (T2): tres días de ayuno y dos días de alimentación, y tratamiento 3 (T3): dos días de ayuno y tres de alimentación. Se utilizó alimento de 35% de proteína, suministrado al 3% de la biomasa total dos veces al día. Al culminar el periodo experimental, los animales experimentales se anestesiaron y se les tomaron muestras de sangre para evaluar dife rentes parámetros metabólicos y hormonales. Posteriormente, se sacrificaron, pesaron y midieron; luego, se pesaron sus vísceras y una porción de músculo blanco se obtuvo para determinar el contenido de proteína y energía. Al final del ensayo, se calculó la sobrevivencia. Luego, de acuerdo con los resultados, se concluyó que no hubo diferencias significativas en la mayoría de los parámetros analizados, por lo que se infiere que los juveniles de cachama blanca son capaces de adaptarse metabólicamente a la carencia parcial de alimento y optimizar la respuesta en su desempeño.

The general purpose of this experiment was to evaluate the effect of food restriction on the productive and physiological performance of Cachama Blanca juveniles and on the content of protein and energy in their muscles. 64 animals, with an average weight (P) of 58.40 ± 6.56 g and 14.65 ± 0.75 cm of Total Length (LT), were divided at random in 16 tanks. During eight weeks the animals received the following treatments: daily feeding; treatment 1 (T1): one day of fasting followed by one day of feeding; treatment 2 (T2): three days of fasting and two days of feeding; and treatment 3 (T3): two days of fasting and three days of feeding. Food containing 35% protein, at 3% of the total biomass was supplied twice a day. At the end of the experimental period the animals were anaesthetized and blood samples were taken in order to evaluate different metabolic and hormonal parameters. Later, the animals were sacrificed, weighted and measured. The viscera, liver and a portion of white tissue were used in order to determine protein and energy. The experimental design was done completely at random with three treatments and four repetitions, each done with four animals. At the end of the experiment, survival rate was calculated. The results did not show significant differences in most of the parameters analyzed. It was concluded that the juveniles of Cachama Blanca are capable of adapting metabolically to the partial lack of food and of optimizing their performance response.

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Weigh gain, length, and survival of Pacu (Piaractus brachypomus) larvae were analyzed after they were fed one of four diets. At 36 hours post-hatching larvae were fed for the first time and during three consecutive days: Artemia salina nauplii (T1), wild plankton filtered to 200 microns (T2) , concentrated powder with 48% crude protein (T3) or no diet (fasting, T4). Animals were kept at a density of 70 larvae per liter. Statistically significant differences were observed with respect to the final weight for T1, T2, T3, and T4 (2.2 ± 0.3a, 1.7 ± 0.3b, 1.5 ± 0.3bc, 1.5 ± 0.2c mg, respectively) , final length (6.37 ± 0.29a, 0.20b ± 6.16, 5.95 ± 0.27c, 0.26c ± 5.87 mm, respectively), weight gain (0.77 ± 0.39a, 0.31b ± 0.34, 0.16 ± 0.37bc, 0.08 ± 0.21 c mg, respectively) and length gain (0.39 ± 0.17A, 0.18 ± 0.15b, 0.16c ± -0023, -0102 ± 0.15c mm, respectively). The T1 diet had the best results for optimal growth, followed by T2. The survival rate was not statistically different among treatments. These data suggest that the initial diet composition can affect subsequent growth characteristics of Pacu larvae.

Se evaluó la ganancia de peso, la longitud y la supervivencia de larvas de cachama blanca (Piaractus brachypomus) alimentadas con varias dietas. A las 36 horas post-eclosión las larvas se alimentaron por primera vez y durante tres días consecutivos con nauplios de Artemia salina (T1), plancton silvestre filtrado a 200 μm (T2), concentrado pulverizado con 48% de proteína bruta (T3), o ayuno (T4). Los animales se mantuvieron a una densidad de 70 larvas por litro. Se observaron diferencias estadísticas significativas (p<0.05) con respecto al peso final para los tratamientos T1, T2, T3, y T4 (2.2 ± 0.3a; 1.7 ± 0.3b; 1.5 ± 0.3bc; 1.5 ± 0.2c mg, respectivamente), longitud final (6.37 ± 0.29a; 6.16 ± 0.20b; 5.95 ± 0.27c; 5.87 ± 0.26c mm, respectivamente), ganancia de peso (0.77 ± 0.39a; 0.34 ± 0.31b; 0.16 ± 0.37bc; 0.08 ± 0.21c mg, respectivamente) y ganancia de longitud (0.39 ± 0.17a; 0.18 ± 0.15b; -0.023 ± 0.16c; -0.102 ± 0.15c mm, respectivamente). El T1 presentó los mejores resultados, seguido por T2. El porcentaje de sobrevivencia no tuvo diferencia estadística significativa entre tratamientos.

Foram utilizadas larvas de pirapitinga (Piaractus brachypomus) foram mantidas em densidade de 70 larvas/L. Por três dias consecutivos, as larvas eram alimentadas com náuplios de Artemia salina (T1), plâncton selvagem filtrado (200 μm) (T2), ração em pó com 48% de PB (T3) e o tratamento controle era mantido em jejum (T4). Os resultados mostraram diferença significativa (p <0.05) no peso final (2.2 ± 0.3 a; 1.7 ± 0.3 b; 1.5 ± 0.3 bc; 1.5 ± 0. 2c mg.), no comprimento final (6.37 ± 0.29 a; 6.16 ± 0.20 b; 5.95 ± 0.27 c; c 5.87 ± 0.26 mm.), no ganho de peso (0.77 ± Um 0.39 a; 0.34 ± 0.31 b; 0.16 ± 0.37 bc; c 0.08 ± 0.21c mg.) e no ganho de comprimento (0.39 ± 0.17 a; 0.18 ± 0.15 b; -0.023 ± 0.16 c; -0.102 ± 0.15c mm). Os tratamentos T1 e T2 mostraram os melhores resultados em relação aos parâmetros anteriormente citados. Contudo, nenhum tratamento mostrou diferença significativa na porcentagem de sobrevivência.

RESUMEN

En Colombia, el surfactante Cosmoflux® 411F es usado en fumigaciones de cultivos ilícitos para mejorar la efectividad del glifosato. El uso del Cosmoflux® 411F no está soportado por estudios toxicológicos. Los objetivos del presente trabajo fueron determinar las lesiones anatomopatológicas derivadas de la exposición al Cosmoflux® 411F y establecer la concentración letal 50 (CL50) a 96 horas en cachama blanca (Piaractus brachypomus). Se utilizaron juveniles de cachama blanca (40 g) en dos experimentos: 1) toxicidad subletal (n =126) y, 2) determinación de la CL50 (n =84). Las concentraciones del ensayo de toxicidad subletal fueron: 0 mg/l (Tratamiento 0), 0.17 mg/l (Tratamiento 1), 0.34 mg/l (Tratamiento 2), 0.68 mg/l (Tratamiento 3), 1.36 mg/l (Tratamiento 4), y 2.72 mg/l (Tratamiento 5), en sistema semiestático. Para determinar la CL50 las dosis fueron: 3000, 3450, 3900, 4350 y 4800 mg/l de Cosmoflux® 411F. La CL50 obtenida fue de 4417.99 mg/l. En los peces se evidenció leve disminución de la actividad de nado. A la necropsia se halló palidez del hígado y acumulación de material mucoso en las branquias. Por histopatología se halló: vacuolización de hepatocitos, hiperplasia de células epiteliales, de cloro y caliciformes branquiales, vacuolización de enterocitos, aumento de centros melanomacrófagos renales, gliosis, degeneración neuronal e infiltración de células granulares eosinofílicas/células mastocitos en telencéfalo. Los hallazgos concuerdan con lo reportado en peces expuestos a surfactantes, exceptuando las lesiones del sistema nervioso central que pueden tener consecuencias sobre interacciones sociales, de alimentación y reproducción de la especie; siendo necesario profundizar la investigación sobre dicho efecto. El hígado, branquias y piel constituyen órganos blanco de la acción tóxica. La CL50 hallada (4417.99 mg/l) es alta comparada con lo reportado en surfactantes no-iónicos.

In Colombia, surfactant Cosmoflux® 411F is used for the fumigation of illicit crops in order to improve the glyphosate herbicide activity. The use of Cosmoflux® 411F is not supported by toxicological surveys. The aims of this study were to determinate the anatomopathological lesions due to the exposure to Cosmoflux® 411F and to establish lethal concentration 50 (LC50) to 96 hours in cachama blanca (Piaractus brachypomus). Juveniles of cachama blanca (40 g) in two assays were used: 1) sublethal toxicity (n= 126) and 2) determination of LC50 (n=84). Sublethal toxicity assay concentrations were: 0 mg/l (Treatment 0) 0.17 mg/l (Treatment 1), 0.34 mg/l (Treatment 2), 0.68 mg/l (Treatment 3), 1.36 mg/l (Treatment 4), and 2.72 mg/l (Treatment 5); through semi-static system. For the determination of LC50 of Cosmoflux® 411F 3000, 3450, 3900, 4350 y 4800 mg/l concentrations were used. LC50 was 4417.99 mg/l. Animals showed slight decrease in swimming activity. At necropsy examination were found paleness in liver and whitish material accumulation in top of gill filament. Histopathologically, it was found fatty degeneration and hepatocyte vacuolization, epithelial cells, chloride cells and mucous cells hyperplasia, enterocyte vacuolization, increase in the expression of melanomacrophage centres in kidney, gliosis, neuronal degeneration and infiltration of eosinophilic granule cells/mast cells in telencephalon. With exception of central nervous system lesions, the findings are according to the reported in literature about surfactant exposure in fish. Central nervous system effects can have consequences on feeding, reproductive and social interactions, due to close telencephalon/olfactory system relationship, being necessary to deep in research to these processes. In same way, liver, gills and skin are target organs of toxic action of this xenobiotic. LC50 is high (4417.99 mg/l) compared with that reported for other nonionic surfactants.

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