Evaluación del desempeño zootécnico de alevinos de Piaractus brachypomus alimentados con dietas que aporten diferentes niveles de energía / Evaluation of the zootechnic performance of Piaractus brachypomus fry feded with diets that provides different levels of energy / Avaliação do desempenho zootécnico de alevinos de Piaractus brachypomus alimentados com dietas que aportem diferentes níveis de energia

Resumen Este experimento tuvo como objetivo evaluar el desempeño productivo de alevinos de Piaractus brachypomus, al ser alimentados con dietas isoproteicas (34%) con siete niveles de energía bruta (EB) (3750, 3865, 3980, 4095, 4210, 4325, 4440 (Kcal/kg) con las siguientes relaciones de energía / proteína: 11,03; 11,37; 11,74; 12,04; 12,38; 12,72 y 13,06 Kcal EB/g PB. El diseño experimental fue completamente aleatorizado, con cuatro repeticiones. El experimento tuvo una duración de 60 días. Se usó un lote de 280 alevinos (peso medio inicial de 1,89 ± 0,14 g), en número de 10 peces por acuario. Se evalúo el efecto de las dietas en cuanto a peso final (PF), ganancia de peso (GP), consumo de alimento (CA), tasa de conversión alimenticia (TCA), tasa de crecimiento específica (TCE), consumo de proteína (CP), tasa de eficiencia proteica (TEP), consumo de energía (CE), tasa de eficiencia energética (TEE) y un análisis de carcasas del 10% de la población al día 60 del experimento. Finalmente, los datos fueron sometidos a un análisis de varianza (ANOVA). Se concluyó que el nivel mínimo de energía que atiende los requerimientos de esta especie es de 3980 Kcal/Kg, con una relación de EB: PB de 11,74 Kcal de EB/g de PB, siendo semejante estadísticamente (P>0,05) con los niveles superiores probados.

Abstract The purpose of this experiment was to evaluate the productive performance of Piaractus brachypomus fry, fed with isoproteic diets (34%) with seven levels of gross energy (EB) (3750, 3865, 3980, 4095, 4210, 4325,4440 Kcal / kg) with the next relations of gross energy / crude protein: 11,03; 11,37; 11,74; 12,04; 12,38; 12,72 and 13,06 Kcal EB / g PB. The experimental design was completely random, with four repetitions. The experiment lasted 60 days. A batch of 280 fry were used (initial average weight 1,89 ± 0,14 g) in number of 10 fishes per aquarium. The effect of the diets was evaluated in terms of final weight (PF), weight gain (GP), feed intake (CA), feed conversion rate (TCA), specific growth rate (TCE), protein consumption (CP), protein efficiency ratio (TEP), energy consumption (CE), energy efficiency rate (TEE) and an analysis carcasses of 10% of the population on day 60 of the experiment. Finally, the data were subjected in a variance analysis (ANOVA). It concluded that the minimum level of energy that meets the requirements of this specie is 3980 Kcal/ kg with a ratio of EB: PB 11,74 EB kcal / g of PB being statistically (P>0,05) similar to higher levels tested.

Resumo Esse experimento teve por objetivo avaliar o desempenho produtivo de alevinos de Piaractus brachypomus, sendo arraçoados com dietas isoproteicas (34%) com sete níveis de energia bruta (EB) (3750, 3865, 3980, 4095, 4210, 4325 e 4440 Kcal/kg) com as seguintes relações de energia bruta / proteína bruta: 11,03; 11,37; 11,74; 12,04; 12,38; 12,72 e 13,06 Kcal EB/g PB. O delineamento experimental foi inteiramente casualiado, com quatro repetições. O experimento teve duração de 60 dias. Empregou-se um lote de 280 alevinos (peso médio de 1,89 ±0,14 g) em número de dez peixes por aquário. Avaliou-se o efeito das dietas quanto ao peso final (PF), o ganho de peso (GP), o consumo de alimento (CA), a conversão alimentar (TCA), a taxa de crescimento específica (TCE), consumo de proteína (CP), taxa de eficiência proteica (TEP), consumo de energia (CE), taxa de eficiência energética (TEE) e uma análise das carcaças de 10% da população no dia 60 do experimento. Finalmente os dados foram submetidos a uma análise de variância (ANOVA). Concluiu-se que o nível de mínimo energia que atende as exigências da espécie é de 3980 Kcal/Kg, com uma relação de EB:PB de 11,74 Kcal de EB/g de PB, sendo estatisticamente semelhantes (P>0,05) com os níveis superiores testados.

A bicha na emergência da homossexualidade cultural: peter fry e o que o inglês não viu / La bicha en la aparición de la homosexualidad cultural: peter fry y lo que el inglés no vio / Bicha in the emergence of cultural homosexuality: peter fry and what the englishman didn't see

Resumo Procurando desenvolver a perspectiva da bicha, empreende-se uma leitura crítica da obra de Peter Fry relativa à antropologia da homossexualidade como um meio para promover questionamentos à formação identitária do gay, que é base das políticas de diversidade sexual no Brasil. O paradigma cultural que Fry ajuda a estabelecer, contestando a abordagem naturalista da homossexualidade, possibilita um lugar para a bicha nas tramas do saber científico. Mas o impasse representacional em relação ao devir marca a obra de Fry. O resultado da reviravolta é a redução da bicha ao negativo, como o contrário da homossexualidade. Extemporânea e involuída, contudo, não seria a bicha produzida no seio da modernidade uma ruptura na ordem da evolução e do progresso, signo de um desvio histórico?

Resumen Buscando desarrollar la perspectiva de la bicha (el maricón), se emprende una lectura crítica de la obra de Peter Fry en la antropología de la homosexualidad como un medio para promover el cuestionamiento de la formación de la identidad de la comunidad gay, que es la base de las políticas de diversidad sexual en Brasil. El paradigma cultural que Fry ayuda a establecer, desafiando el enfoque naturalista de la homosexualidad, proporciona un lugar para la bicha en las parcelas del conocimiento científico. Pero un atolladero representacional en relación con el devenir marca el trabajo de Fry. El resultado de la voltereta es la reducción de la bicha a la negativa, como lo contrario de la homosexualidad. Extemporánea e involutiva, sin embargo, no sería la bicha producida dentro de la modernidad una ruptura en el orden de la evolución y del progreso, ¿signo de un desvío histórico?

Abstract In order to develop abichaperspective, a critical reading of Peter Fry's work on the anthropology of homosexuality functions as a means to promote questions about the identity construction of gays, which is the basis of sexual diversity policies in Brazil. The cultural paradigm that Fry helps to establish by challenging the naturalistic approach to homosexuality provides a place for the bicha in the scientific knowledge. However, a representational impasse in relation to its development marks Fry's work. It results on the reduction of thebichato a negative, as being the opposite of homosexuality. Being seen as extemporaneous and "un-evolved", however, wouldn't thebichaproduced within modernity be a rupture in the order of evolution and progress, and therefore a sign of historical deviation?

Immunolocalization of morphogen sonic Hedgehog in salmon fry (Salmo salar) / Inmunolocalización del morfógeno sonic Hedhehog en alevines de salmón (Salmo salar)

With the purpose of carrying out a diagnosis of the different pathologies that affect the salmon fry stage (Salmo salar) and analyze the regeneration phases of the organizational centers and subjacent tissue in case of an amputation, we realized a study that allowed identifying the temporary and spatial location of the Sonic Hedgehog (Shh) morphogen in hatched fry stage. Fifteen salmon fry (Salmo salar) were used. They were anesthetized with 5 % benzocaine (BZ-20®, Veterquímica), fixed in 10 % buffered formalin, and embedded in paraffin, Shh polyclonal antibody (Santa Cruz H-160, rabbit) was used diluted at 1/100. They were subsequently rinsed in PBS-1 % Triton and incubated with anti-rabbit conjugated polymer antibody and HRP for 10-15 min. The development was done with DAB (Vector) for 1-5 min. The negative control was incubated without primary antibody. As an internal positive control the notochord was considered. Serial sagittal sections were analyzed consigning tissues and organs marked positively and were described morphologically. The objective of recognizing the spatial and temporal location of Shh was achieved. The notochord, spinal cord neurons and ganglia, the basal layer of the skin and also the lepidotriquias escleroblastos were positively identified for Shh. Finally positivity was also observed in the intestine and renal tubules. The heterogeneity observed in the location of the Shh morphogen suggests its potential use as a marker of regulatory centers in Salmo salar, and a potential advantage in the diagnosis of malformations of salmon fry stage, in addition to a better understanding of tissue regeneration.

Con el fin de llevar a cabo un diagnóstico de las diferentes patologías que afectan a la etapa de alevín de salmón (Salmo salar) y analizar las fases de regeneración de los centros de organización y el tejido subyacente en caso de una amputación, se realizó un estudio que permitió identificar la ubicación temporal y espacial del morfógeno Sonic hedgehog (Shh) en la etapa de alevines eclosionados. Se utilizaron quince alevines de salmón (Salmo salar). Fueron anestesiados con benzocaína al 5% (BZ-20®, Veterquímica), se fijaron en formalina tamponada al 10%, e incluidos en paraplast. Se utilizó Shh anticuerpo policlonal (Santa Cruz H-160, conejo) dilución 1/100. Se enjuagaron posteriormente en PBS-1% Triton y se incubaron con anticuerpo conjugado con polímero anti-conejo y HRP durante 10-15 minutos. Se utilizó como sustrato DAB (Vector) durante 1-5 minutos. El control negativo se incubó sin anticuerpo primario. Como un control positivo interno se consideró la notocorda. Se analizaron secciones sagitales en serie consignando los tejidos y órganos marcados positivamente y se describieron morfológicamente. Se logró el objetivo de reconocer la localización espacial y temporal de Shh. La notocorda, las neuronas de la médula espinal y los ganglios, la capa basal de la piel y también los escleroblastos de las lepidotriquias fueron identificados positivamente para Shh. También se observó positivo el intestino y los túbulos renales. La heterogeneidad observada en la ubicación del morfógeno Shh sugiere su uso potencial como un marcador de los centros de regulación en Salmo salar, y una ventaja potencial en el diagnóstico de las malformaciones de la etapa de alevines de salmón, además de una mejor comprensión de la regeneración de tejidos.

Effect of temperature on the expression of IFN-1 (α), STAT-1 and Mx-1 genes in Oncorhynchus mykiss (Salmoniformes: Salmonidae) exposed with the virus of the infectious pancreatic necrosis (IPNV) / Efecto de la temperatura sobre la expresión de genes IFN-1(α), STAT-1 y Mx-1 en alevines de trucha arcoíris Oncorhynchus mykiss (Salmoniformes: Salmonidae) expuestos al el virus de la necrosis pancreática infecciosa (IPNV)

The infectious pancreatic necrosis (IPNV) is the causative agent of an acute illness well characterized in salmonids worldwide. Clinical signs and mortality rates are dependent on several factors such as the viral dose, the age of the fish, the water temperature, among others. An experimental study was conducted to measure the effect of temperature on the gene expression profile of IFN-1(α), STAT-1 and Mx-1 in rainbow trout fry, exposed to IPNV. Fry (n=198) were exposed at 8, 12 and 16°C, and samples were taken for 21 days to determine the virus titer and gene expression. In the first 11 days the greatest viral titer was recorded at 8°C compared with the values obtained at 12 and 16°C. At 8°C, there was a significant increase on day 4 of mRNA Mx-1 (t-test, p<0.05), time in which the viral titer began to decrease. Furthermore, as the viral titer increased, STAT-1 and Mx-1 (r=0.91) and (r=0.96) increased, respectively. The animals were able to recover from day 4 from some of the symptoms of IPN. Clinical disease was developed only in fish exposed to 12°C and all died between days 6 and 14, despite the highly significant increase shown in the average expression level of Mx-1, compared with the values recorded at 8°C and 16°C (Tukey, p<0.0001). Additionally, the expression profiles of IFN-1(α) and STAT-1 decreased completely (~0.016) and (~0.020 times) on day 7. The highest expression level of IFN-1(α), occurred at 16°C (Tukey, p<0.0005). Fry exposed at 16°C were normal during the experiment. IFN-1(α) possibly generated a protector effect from day 2 when they showed a significant expression increase compared with the results at 8°C and 12°C (t-student, p<0.0001); however, STAT-1 was not significantly affected by temperature, although the highest average expression value was recorded at 16°C. Our research supports the expression of relevant anti-viral response genes as IFN-1(α), STAT-1 and Mx-1 are physiologically modulated by the water temperature, directly influencing the development of the IPN disease in rainbow trout.

El virus de la necrosis pancreática infecciosa (IPNV) es el agente etiológico de una enfermedad aguda bien caracterizada en salmónidos alrededor del mundo. Los signos clínicos y la tasa de mortalidad dependen de varios factores tales como la dosis viral, la edad del pez y la temperatura del agua, entre otros. Un estudio experimental se llevó a cabo para medir el efecto de la temperatura sobre el perfil de expresión génica de IFN-1(α), STAT-1 y Mx-1 en alevines de trucha arcoíris expuestos con IPNV. Los alevines (n=198) fueron expuestos a 8, 12 y 16°C, y se tomaron muestras durante 21 días para determinar el título viral y la expresión génica. En los primeros 11 días el mayor titulo viral se registró a 8ºC en comparación con 12 y 16. A 8°C, existió un incremento significativo en el día 4 del ARNm de Mx-1 (t-test, p<0.05), momento en que el título viral empezó a disminuir. Además conforme el título viral aumentaba, también STAT-1 y Mx-1 aumentaron (r=0.91) y (r=0.96) respectivamente. Los animales fueron capaces de recuperarse desde el día 4 de algunos de los síntomas de IPN. La enfermedad clínica se desarrolló únicamente en peces expuestos a 12°C y todos murieron entre el día 6 y 14, a pesar del incremento altamente significativo mostrado en el nivel promedio de expresión de Mx-1 a 12°C, comparados con los valores registrados a 8 y 16°C (Tukey, p<0.0001). Además los perfiles de expresión de IFN-1(α) y STAT-1 decrecieron el día 7 completamente (~0.016) y (~0.020) veces, respectivamente. El nivel de expresión promedio más alto de IFN-1(α) se registró a 16°C (Tukey, p<0.0005). Los alevines expuestos a 16°C se mostraron normales durante el experimento. IFN-1(α) posiblemente generó un efecto protector desde el día 2 cuando mostró un aumento significativo en comparación con los resultados a 8 y 12°C (t-student, p<0.0001); sin embargo, STAT-1 no fue afectado de manera significativa por la temperatura, aunque el más alto valor de expresión promedio se registró a 16°C. Nuestra investigación confirma que la expresión de genes relevantes de respuesta antiviral como IFN-1(α), STAT-1 y Mx-1 son fisiológicamente modulados por la temperatura del agua, influyendo directamente en el desarrollo de la enfermedad de IPN en trucha arcoíris.

Centrocestus formosanus (Opisthorchiida: Heterophyidae) como causa de muerte de alevines de tilapia gris Oreochromis niloticus (Perciforme: Cichlidae) en el Pacífico seco de Costa Rica

Centrocestus formosanus (Opisthorchiida: Heterophyidae) as a cause of death in gray tilapia fry Oreochromis niloticus (Perciforme: Cichlidae) in the dry Pacific of Costa Rica. Centrocestus formosanus is a zoonotic trematode from Asia and has been mainly associated as cause of death of cultured fish. To identify pathogen trematode species in tilapia fry (Oreochromis niloticus) and to determine mollusks hosting these parasites, freshwater mollusks were collected from tilapia cultured ponds and experimental infections were carried out with tilapia fries and different mollusk species. A total of 907 freshwater mollusks were obtained from tilapia ponds and were identified to species level, four gastropods and one bivalve were determined: Melania tuberculata, Melanoides turricula, Pomacea flagellata, Haitia cubensis and Anodontiles luteola. For the first time, the presence of M. turricula and H. cubensis are reported in Costa Rica. Seven morphotypes of cercariae (Xifiodiocercaria, Equinostoma, Oftalmocercaria, Parapleurolofocercus, Cistocerca, Furcocercaria and Leptocercaria) parasitizing all five species of mollusks were found, all of distome type. Experimental exposure of tilapia fry to M. tuberculata demonstrated that the parapleurolofocercus morphotype found in the mollusk is in accordance with the finding of C. formosanus in tilapia fry. An abundance and mean intensity of 1018-1027 digeneans per gill in each exposed fish was determined. Centrocestus formosanus is reported for the first time in Costa Rica, for which the primary and secondary intermediate hosts were also determined. Rev. Biol. Trop. 58 (4): 1453-1465. Epub 2010 December 01.

Centrocestus formosanus es un parásito trematodo zoonótico originario de Asia asociado con muertes de peces principalmente de cultivo. 907 moluscos provenientes de estanques sembrados con tilapias, seleccionados uno por provincia fueron identificados al nivel taxonómico especifico. Se identificaron cuatro gastrópodos y un bivalvo: M. tuberculata, M. turricula, P. flagellata, H. cubensis y A. luteola. Se reporta, por primera vez, la presencia de dos especies de moluscos en Costa Rica. Se identificaron siete morfotipos de cercarias parasitando las cinco especies de moluscos encontradas. En la segunda exposición experimental se demostró que el morfotipo parapleurolofocercus encontrado en M. tuberculata concuerda con el hallazgo de C. formosanus en alevines de tilapia, después del examen clínico, anatomopatológico y parasitológico realizado a los alevines expuestos. Las metacercarias fueron extraídas del quiste utilizando microagujas y micropinzas lavadas en solución salina fisiológica (0.65%), fijadas en formol caliente al 4% y después esquematizadas con una cámara clara adaptada a un microscopio fotónico, estimándose una abundancia e intensidad media de 1018-1027 digeneos por branquia en cada pez parasitado, determinándose así el hospedador intermediario primario y secundario del parásito. En el presente trabajo se reporta por primera vez Centrocestus formosanus en Costa Rica.

Exigência de proteína de alevinos de piavuçú / Requirement of protein for piavuçu fry

O piavuçu Leporinus macrocephalus apresenta hábito alimentar onívoro, alimentando-se de vegetais e sementes. Os alimentos protéicos apresentam maior custo se comparados aos alimentos energéticos. Portanto, quanto maior o teor de proteína nas rações, maior pode ser o custo de produção dos peixes. O presente trabalho objetivou avaliar a exigência de proteína bruta na dieta de alevinos de piavuçu (L. macrocephalus). Foram distribuídos em um delineamento inteiramente casualizado 125 alevinos (0,625 0,011g), em 25 aquários de 30l, constituindo cinco tratamentos e cinco repetições. As dietas foram formuladas de forma a conter 22, 26, 30, 34 e 38 por cento de proteína bruta e 3200kcal ED kg-1. Os peixes foram alimentados quatro vezes ao dia (8h, 11h, 14h e 17h). Os parâmetros de qualidade de água durante o período experimental permaneceram dentro das condições normais para o bom desempenho dos animais. Os melhores resultados de peso final, ganho de peso e conversão alimentar aparente foram observados para os peixes alimentados com rações contendo 34 e 38 por cento de PB, diferindo (P<0,05) dos tratamentos com 22, 26 e 30 por cento de PB. Também não ocorreu variação na deposição protéica e na taxa de eficiência protéica na carcaça dos animais. Recomenda-se a utilização de 34 por cento de proteína bruta na dieta de alevinos de piavuçu (L. macrocephalus).

The piavuçu Leporinus macrocephalus presents omnivore feeding habits, eating vegetables and seeds. The protein feed presents higher cost compared to energetic feed. Therefore, the higher protein content is in the ration, the higher might be the production cost of the fish. This study aimed to evaluate the gross protein need in the diet of piavuçu fingerlings (L. macrocephalus). 125 fingerlings (0.625±0.011g) were distributed into 25 aquariums with a 30L capacity at a random design, with five treatments and five repetitions. The diets were formulated to contain 22; 26; 30; 34 and 38 percent of gross protein and 3200kcal DeE kg.-1 The fish were fed four times a day (8:00am; 11:00am; 2:00pm; and 5:00pm). The water quality parameters during the experimental period remained in the normal conditions for good animal development. The best results of the final weight, gain weight and apparent feeding conversion were observed for fishes which were fed with diets containing 34 and 38 percent of gross protein, having differences (P<0.05) on the treatments with 22, 26 and 30 of PB. Also there was no variation in the protein deposition and protein efficiency rate in the animals' carcass. It is recommended to use 34 percent of protein gross on the diets of piavuçu fingerlings.