Effects of different dietary of protein and lipid levels on the growth of freshwater prawns (Macrobrachium carcinus) broodstock

ABSTRACT Objective. Evaluate the effects of varying dietary protein and lipid levels on the growth and body composition of adult freshwater prawns, Macrobrachium carcinus (Linnaeus 1758), in a recirculation system for 11 weeks (77 days). Materials and methods. The experimental treatments were assigned in triplicate. Six test diets were formulated with three different protein levels (35, 40 and 45%) and two lipid levels (8 and 13%). Results. The highest survival rate, growth indices and feed utilization were observed for M. carcinus adults fed protein:lipid diets of 35:13, 40:13 and 45:13, and the lowest values for these parameters were recorded for prawns fed diets with the lowest lipid levels; the differences in these parameters between these types of diets were significant (p<0.05). A nonsignificant tendency for an increased percentage of protein in the body with an increased dietary protein level was observed. The percentage of lipids decreased with an increasing dietary protein level, and no definite trends in ash content were found. Conclusions. The results suggest that a diet with 35% dietary crude protein and 13% lipids enhances the growth and body composition of adult M. carcinus

Effect of white spot syndrome virus (WSSV) and water exchange on survival and production of Litopenaeus vannamei under semi-intensive culture conditions.

A study was performed in two commercial shrimp farms in the province of Guasave, north of Sinaloa, Mexico, to assess the effects of the presence of the white spot syndrome virus (WSSV) and of water exchange on the growth rate, production, and survival of the Pacific white shrimp, Litopenaeus vannamei, during the fall-winter season in semi-intensive culture ponds. The experiment consisted of four treatments; in the first (T1), three earthen ponds with water exchange, were stocked with PCR-positive for white-spot syndrome virus (WSSV) postlarvae. In the second (T2), three earthen ponds were stocked likewise (PCR-positive), but without water exchange. In the third (T3), three earthen ponds, with water exchange were stocked with PCR-negative for white-spot syndrome virus (WSSV) postlarvae. In the fourth (T4), three earthen ponds were stocked likewise (PCR-negative), but without water exchange. The average growth rates were 0.56, 0.56, 0.80, and 0.75 g/week for T1, T2, T3, and T4, respectively. Survival was 23.2% (T1), 26.1% (T2), 64.3% (T3), and 66.1% (T4). Production ranged between 252.60 and 847.00 kg/ha, with the lowest production in T2 and the highest in T3. Feed conversion ratio ranged from 1.00 for T3 to 1.70 for T2. The final average weight ranged between 10.6 g (T2) to 12.5 g (T3). The WSSV can affect negatively the growth rate (30%), the survival (64%), and the production (69%) in comparison with PCR-negative organisms.No differences in weight were found between WSSV-infected and non-infected individual shrimps, as well as in nested-PCR positive against single-step PCR positive organisms.It found that the zero water exchange strategy could be feasible for the culture of the white shrimp L. vannamei at a commercial level during the fallwinter season

Ecología alimentaria de camarones peneidos en los sistemas lagunar-estuarinos tropicales

Shrimps are an important resource in coastal lagoons because they use these ecosystems for their development. Although some authors classified the Penaeidae as detritivores, it was shown that their diet comprises a greater variety of food items. Many authors had reported that shrimps have a diversified diet that includes several elements of the benthic community. This review describes the feeding ecology of the shrimps in coastal lagoon-estuarine systems, with emphasis on the following: the effect of the environment on the shrimps’ natural food; techniques for identification of items in shrimps gut contents and stable isotope compositions; consideration of the importance of plants and small animals in the diet; and the effect of mangroves and lagoon-estuarine system on feed ecology. The abundance of penaeid appears to be primarily affected by stochastic variations in environmental factors. However, it has been found that the relationships between macroinfauna, macrofauna and environmental conditions in a tropical estuary may result in more interactions with their predators than a direct response to physical-chemical factors. The combination of the study of shrimps guts contents and stable isotopes shows a composition and seasonal variation in the diets, as well as the source of carbon and nitrogen contained in the shrimp’s tissues. In general, the studies suggest that herbaceous detrital inputs to the food web are dominant in supporting shrimps in salt marshes, but phytoplankton or benthic algae may be equally or more important food sources.Los camarones son recursos importantes en las lagunas costeras porque utilizan el ecosistema para su desarrollo. Aunque algunos autores clasifican a los camarones Penaeidae como detritívoros, se encontró que su dieta comprende una gran variedad de ítems. Muchos autores han reportado que los camarones tienen una dieta diversificada que incluye varios elementos de la comunidad béntica. Esta revisión describe la ecología alimentaria de los camarones en los sistemas lagunar- estuarinos, con énfasis sobre los siguientes aspectos: el efecto del ambiente sobre el alimento natural de los camarones; técnicas para la identificación de ítems en los contenidos estomacales de los camarones y la composición de isotopos estables; consideraciones sobre la importancia de las plantas y pequeños animales en la dieta; y el efecto de los manglares y sistema lagunar-estuarino sobre la ecología alimentaria. La abundancia de peneidos parece ser principalmente afectado por variaciones estocásticas en factores ambientales. Sin embargo, se ha encontrado que las relaciones entre macroinfauna, macrofauna y condiciones ambientales en un estuario tropical pueden resultar en más interacciones con sus depredadores que una respuesta directa a factores fisico-químicos. La combinación del estudio de los contenidos estomacales e isotopos estables muestra la composición y las variaciones estacionales en las dietas, también, como la fuente de carbón y nitrógeno contenida en el tejido de los camarones. En general, los estudio sugieren que la entrada de detritus herbáceos al tejido de alimentos son dominantes en la alimentación de los camarones en las marismas, pero el fitoplancton o las algas bénticas pueden ser fuentes de alimento igual o más importantes que los detritus herbáceos

Evaluación de algunos parámetros de calidad del agua en un sistema cerrado de recirculación para la acuicultura, sometido a diferentes cargas de biomasa de peces

Utilizing different loadings of biomass of the Nile Tilapia Oreochromis niloticus and rainbow trout Oncorhynchus mykiss, some water quality parameters were evaluated in a closed aquaculture recirculating system. The systems is integrated by six culture tanks, a sedimentation cistern, two submerged bio-filters, a fast sand filter, two pumps, a reconditioning-water reservoir and a unit of ultraviolet light lamps. Fishes were fed twice a day for 120 days with 2% of their total biomass. The following water quality parameters were recorded: water temperature, dissolved oxygen, pH, total ammonium nitrogen (TAN), ammonia, nitrate and chemical oxygen demand. The data were analyzed with a one-way ANOVA to determine statistical differences in the components of the system. The average values of TAN and nitrate indicated a high efficiency of the nitrification process at different fish loading of biomass. About 50% of TAN and more than 90% of ammonia was stripped into the atmosphere and this explains the low levels measured in the other components of the system. Other causes that contribute to the removal of nitrogen compounds were the assimilation by microorganism accumulated in the bottom of the sedimentation tank and the absorption and adsorption by the sludge. Results showed that the water quality parameters were satisfactory for 99% survivorship and an acceptable growth rate for both fish species.El objetivo de este estudio, fue evaluar algunos parámetros de calidad del agua en un sistema cerrado de recirculación utilizado en la acuicultura, sometido a distintas cargas de biomasa de Tilapia del NiloOreochromis niloticus y de trucha arco iris Oncorhynchus mykiss. El sistema consiste de seis estanques de cultivo, una cisterna de sedimentación, dos piletas con biofiltros sumergidos, un filtro de arena rápido, dos bombas, una pileta de reacondicionamiento y una unidad de lámparas de luz ultravioleta. Los peces fueron alimentados durante 120 días dos veces al día con el 2% de su biomasa total. Se registraron los siguientes parámetros de calidad del agua: temperatura, oxígeno disuelto, pH, nitrógeno amoniacal total (NAT), amoniaco, nitrato y demanda química de oxígeno. Los datos se analizaron con un ANDEVA de una sola vía para detectar diferencias significativas entre los componentes del sistema. Los valores promedio de NAT y nitrato indicaron una alta eficiencia en los procesos de nitrificación, aún cuando el sistema fue sometido a diferentes cargas de biomasa de peces. Los bajos valores detectados de NAT y amoniaco se debieron al arrastre eficiente hacia la atmósfera (50% NAT y más del 90% respectivamente). Otras posibles causas que contribuyeron a la eliminación de los compuestos nitrogenados, fueron la asimilación por microorganismos presentes en los lodos acumulados en la cisterna de sedimentación, además de la absorción y la adsorción por los lodos. Los resultados mostraron que la calidad del agua mantenida en el sistema permitió el 99% de sobrevivencia de ambas especies y una tasa de crecimiento aceptable

Biology and use of the Pacific fat sleeper Dormitator latifrons (Richardson, 1844): state of the art review

The present work is a review of the literature on the native Mexican fish Dormitator latifrons. The aim is to contribute to the integration and systematization of current knowledge to make it easier to identify existing knowledge gaps and breakthroghs Moreover, promote the successful cultivation and protection of this species whose consumption is increasing in Latin America. A review of the articles related to D. latifrons published in international and regional databases was carried out. The articles reviewed focus on taxonomy and systematics, phylogenetic, geographic distribution, ecology, physiology, reproduction, development, pathology, health, and the technologies used to cultivate this fish species. The conclusion is that, even though the cultivation of D. latifrons is of commercial interest in some countries, there are still significant gaps in our knowledge of biology and, consequently, the domestication potential of the species. Filling these gaps will require systematic research efforts on protecting natural populations and improving mass cultivation techniques.Fil: Vega Villasante, Fernando. Universidad de Guadalajara; MéxicoFil: Ruiz González, Luis E.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Basto Rosales, Mao E. R.. Tecnológico Nacional de Bahía de Banderas; MéxicoFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Tintos Gómez, Adrián. Universidad Tecnológica de Manzanillo; MéxicoFil: Montoya Martínez, Cynthia E.. Universidad de Guadalajara; MéxicoFil: Kelly Gutiérrez, Liza D.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Ponce Palafox, Jesús T.. Universidad Autónoma de Nayarit; MéxicoFil: Zapata, Ana. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Badillo Zapata, Daniel. Universidad de Guadalajara; Méxic

Effect of white spot syndrome virus (WSSV) and water exchange on survival and production of Litopenaeus vannamei under semi-intensive culture conditions.

A study was performed in two commercial shrimp farms in the province of Guasave, north of Sinaloa, Mexico, to assess the effects of the presence of the white spot syndrome virus (WSSV) and of water exchange on the growth rate, production, and survival of the Pacific white shrimp, Litopenaeus vannamei, during the fall-winter season in semi-intensive culture ponds. The experiment consisted of four treatments; in the first (T1), three earthen ponds with water exchange, were stocked with PCR-positive for white-spot syndrome virus (WSSV) postlarvae. In the second (T2), three earthen ponds were stocked likewise (PCR-positive), but without water exchange. In the third (T3), three earthen ponds, with water exchange were stocked with PCR-negative for white-spot syndrome virus (WSSV) postlarvae. In the fourth (T4), three earthen ponds were stocked likewise (PCR-negative), but without water exchange. The average growth rates were 0.56, 0.56, 0.80, and 0.75 g/week for T1, T2, T3, and T4, respectively. Survival was 23.2% (T1), 26.1% (T2), 64.3% (T3), and 66.1% (T4). Production ranged between 252.60 and 847.00 kg/ha, with the lowest production in T2 and the highest in T3. Feed conversion ratio ranged from 1.00 for T3 to 1.70 for T2. The final average weight ranged between 10.6 g (T2) to 12.5 g (T3). The WSSV can affect negatively the growth rate (30%), the survival (64%), and the production (69%) in comparison with PCR-negative organisms.No differences in weight were found between WSSV-infected and non-infected individual shrimps, as well as in nested-PCR positive against single-step PCR positive organisms.It found that the zero water exchange strategy could be feasible for the culture of the white shrimp L. vannamei at a commercial level during the fallwinter season

Análisis de la Distribución Espacial del Esfuerzo Pesquero de la Flota Camaronera Mexicana en el Golfo de México y el Mar Caribe por Medio del Sistema Satelital de Monitoreo de Embarcaciones

Se analizaron la distribución espacial y la temporal del esfuerzo de pesca durante la temporada 2005/2006 que desarrolló la flota camaronera mexicana del Golfo de México y del mar Caribe. La información proviene del Sistema Satelital de Monitoreo de Embarcaciones Pesqueras (ssmep), proporcionada por la Comisión Nacional de la Pesca y Acuacultura (conapesca). El análisis de la información muestra que: a) el esfuerzo pesquero se distribuye principalmente en dos grandes zonas: el noroeste del Golfo de México y la Sonda de Campeche; b) la zona de pesca donde se aplica mayor esfuerzo es en la costa norte de Tamaulipas; c) la distribución del esfuerzo pesquero de la flota camaronera está influenciada por las fechas de apertura de la temporada de pesca en las diferentes zonas y d) la información que proviene del sistema satelital de monitoreo de embarcaciones pesqueras es útil para conocer la distribución tanto espacial como temporal del esfuerzo pesquero efectuado por la flota camaronera en las costas mexicanas en el Golfo de México y el mar Caribe

El efecto del nivel de proteína y lípidos sobre la acción dinámica específica y la excreción postprandial en sub-adultos del camarón blanco Litopenaeus vannamei

The study aimed to evaluate the effect of 4 levels of dietary protein (20, 30, 40 and 50%) and lipids (2, 4, 8 and 16%) on the magnitude and duration of specific dynamic action (SDA) and postprandial nitrogen excretion in the subadult white shrimp Litopenaeus vannamei using computer-controlled metabolic chambers (continuous-flow respirometer). We determined the oxygen consumption rate at 1 h intervals until the postprandial oxygen consumption rate returned to the pre-feeding level. Shrimp fed all the diets had significantly higher respiration rates after feeding due to the SDA. Oxygen consumption, the SDA coefficient and the SDA magnitude increased notably with increasing dietary protein content. Shrimp fed the 20% protein diet had the lowest levels of pre- and post-feeding respiration and the smallest SDA. A significant change in the SDA coefficient relative to each lipid level was not demonstrable. Additionally, nitrogenous excretion increased with an increase of dietary protein but not with an increase of lipid level. By estimating the SDA of subadults, the response to standard metabolic rate (SMR) was lower than that reported for juveniles and postlarva white shrimpEl objetivo del estudio fue evaluar el efecto de 4 niveles de proteína (20, 30, 40 y 50%) y lípidos (2, 4, 8 y 16%) sobre la magnitud y duración de la acción dinámica específica (ADE) y la excreción nitrogenada en subadultos del camarón blanco Litopenaeus vannamei usando una cámara metabólica controlada por computadora (respirómetro de flujo continuo). Se determinó la tasa de consumo de oxígeno a intervalos de 1 hora hasta que la tasa de consumo de oxígeno postprandial regresó al nivel de pre-alimentación. Los camarones alimentados con todas las dietas tienen una tasa de respiración significativamente alta después de la alimentación debida a la ADE. El consumo de oxígeno, el coeficiente de ADE y la magnitud de ADE aumentó notablemente con el incremento del contenido de proteína en la dieta. Los camarones alimentados con el 20% de proteína en la dieta tuvieron el nivel más bajo de respiración de pre y post-alimentación y la más baja ADE. Un cambio significativo en el coeficiente de ADE relativo a la energía digestible no fue demostrado para cada uno de los niveles de lípidos. Adicionalmente, la excreción nitrogenada aumento con el incremento del nivel de proteína en la dieta, pero no con el incremento del nivel de lípidos. Al estimar la ADE de subadultos se encontró que la tasa metabólica estándar (SMR) fue menor que la reportada para juveniles y postlarvas de L. vannamei