http://hdl.handle.net/1834/1379 Mon, 10 Jun 2013 10:52:16 GMT 2013-06-10T10:52:16Z http://hdl.handle.net/1834/1892 Title: X. Manejo de alimentación en estanques y alimentos amigables con el ambiente Abstract: Se realizaron bioensayos en agua estática para comparar los efectos de 1) la proteína dietaria y 2) el fósforo dietario sobre la acumulación de los nutrientes no asimilados en el agua de cultivo de poslarvas de Penaeus vannamei. Se evaluaron alimentos con 4 niveles de proteína dietaria (10, 18, 25 y 33%) y alimentos con 3 niveles de fósforo (0.4, 0.8 y 1.2%) con fosfato de sodio monobásico (NaH2PO4) como fuente inorgánica de fósforo. La acumulación de Nitrógeno inorgánico disuelto total (NIT) incrementó significativamente con el incremento en el nivel de proteína. El balance de masa de Nitrógeno constituyó el 87% de Nitrógeno que había entrado al medio de cultivo. La asimilación promedio de Nitrógeno en biomasa de camarón fue de 85, 71, 48 y 37% para los alimentos conteniendo 10, 18, 25 y 33% de proteína, respectivamente. La acumulación de fósforo reactivo disuelto (PRD) en el agua se incrementó significativamente con el incremento de los niveles del fósforo dietario. El balance de masa de Fósforo constituyó en promedio el 90% de Fósforo que había entrado al medio de cultivo. Mon, 01 Jan 1996 00:00:00 GMT http://hdl.handle.net/1834/1892 1996-01-01T00:00:00Z http://hdl.handle.net/1834/3102 Title: Water quality in recirculating aquaculture systems (ras) for arctic charr (salvelinus alpinus L.) culture. Authors: Isla Molleda, M. Abstract: Recirculating aquaculture systems (RAS) for fish culture have been used for more than three decades. The interest in RAS is due to their have advantages such as greatly reduced land and water requirements in places where the water resources are limited; but the RAS have also disadvantages like the deterioration of the water quality if the water treatment processes within the system are not controlled properly. The water quality problems in RAS were associated with low DO and high fish waste metabolite levels in the culture water. The objective of this study was to compare water quality in a RAS with water quality in a Limited Reuse System (LRS) for Arctic charr culture taking into account the oxygen demands of the fish; the metabolites production by the fish; the removal of CO2 by the aerators, the removal of ammonia by the biofilter and the removal of waste products in the reuse water. The experiment was conducted in Verid, the Aquaculture Research Facilities of Holar University College, Iceland, during 4 weeks and two different systems were compared during the experiment: a RAS with a biofilter and a LRS. The results of this study indicated that the water quality parameters in both systems were well within the acceptable levels for Arctic charr culture and the water quality was better in the LRS than in the RAS; was demonstrated the important role of the biofilter unit in the RAS and the necessity to control all the water treatment processes within the system, specially when the RAS are using sand filters as one of water treatment components of the system. Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/1834/3102 2008-01-01T00:00:00Z http://hdl.handle.net/1834/2076 Title: Variación en la calidad del pienso artificial durante el almacenamiento y su efecto sobre el Camarón Litopenaeus schmitti Authors: Díaz, V.; Fraga, I.; Fraga, R.; González, M.; Pérez, O.; Escobar, A.; Contreras, R.; Morales, N. Abstract: The effects of artificial diets were studied with different store times, between 1 week and 6.5 months in juveniles culture shrimps in fattening phase. The artificial diets were stored at environmental temperature. The quality of raw materials and finished products were controlled during the storage time with physical, chemical, organoleptical and entomological analysis also it was evaluated the growth, protein efficiency, the food conversion factor and the survival of the shrimps. The nutriments affected during storage were the proteins, lipids and the % of free fatty acids, due fundamentally to the contamination with acarids and insects. It was found that the growth and protein efficiency of juveniles shrimps decreased with the age of the feed, without mortality, the best results were obtained with the 2.5 storage months diet. It was detected the presence of Aphlatoxin B1 in three of the storages in quantities within the established limit for animal food, this affected the growth, but not the survival. It was found that the cost of shrimp culture can be increased by concept of feed between 96 to 535 US$/t of shrimps if feed is consumed with more than 2.5 months of storage, this would reduce the economical efficiency of the production action of the enterprise. It is recommended not to extend the storage feed period more than 2.5 months due to the economical looses which represents deterioration that produces low improvement in the animals. Thu, 01 Jan 2004 00:00:00 GMT http://hdl.handle.net/1834/2076 2004-01-01T00:00:00Z http://hdl.handle.net/1834/2338 Title: Variacion del residual de sulfito en el camarón l. vannamei. Authors: Flores Gutiérrez, E.R.; Espino Martínez, R.; Wong Wong, C.; Pérez Luis, M. Abstract: La absorción y pérdida del sulfito en el camarón reviste gran importancia en su manejo post-cosecha y procesamiento industrial, por cuanto el residual de sulfito puede dar una medida de la protección que presenta el camarón contra la aparición de la melanosis. Se tomaron ejemplares de camarón y se sometieron a un tratamiento en solución de MBS al 8 % empleando diferentes tiempos de inmersión, determinándose los residuales de sulfito en el producto obtenido en cada caso. Adicionalmente, los camarones tratados durante cinco minutos se colocaron en contenedores plásticos con hielo en proporción 1:1, los que fueron colocados en una cámara de refrigeración a una temperatura entre 7 y 10 °C durante siete días. Se determinaron los residuales cada día con el objetivo de cuantificar las pérdidas que se producen durante el almacenamiento en hielo. Posteriormente se obtuvieron las curvas de absorción y pérdida de MBS y se determinaron los modelos matemáticos que explican dichos procesos. Se observó que la mayor absorción se produce en el primer minuto de inmersión. En el proceso de pérdida se conoció que a los seis días de almacenamiento en hielo, el residual de sulfito había mermado en un 93 %.; The absorption and loss of the sulfhite in the shrimp has great importance in their post-crop handling and industrial prosecution, since the residual of sulfhite can give a measure of the protection that presents the shrimp against the appearance of the melanosis. Shrimps were taken and underwent to a treatment in solution of MBS to 8% using different times of immersion, being determined the residual of sulfhite in the product obtained in each case. Additionally, the shrimps tried during five minutes were placed in plastic containers with ice in proportion 1:1, those that were placed in a refrigeration camera to a temperature between 7 and 10 °C during seven days. The residual ones were determined every day with the objective of quantifying the losses that take place during the storage in ice. Later the curves of absorption and loss of MBS were obtained and the mathematical models were determined that explain this processes. It was observed that the biggest absorption takes place in the first minute of immersion. In the process of loss it was known that to the six days of storage in ice, the residual of sulfhite had shrunk in 93%. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/1834/2338 2007-01-01T00:00:00Z