Effect of dietary free fatty acid content on growth and hepatic morphology in sole (Solea Senegalensis) juveniles

Utilization in aquaculture of unusual meals with unbalanced lipid content or inadequate previous treatment may result in harmful state for fish. This research studied the effects caused by different dietary free fatty acid (FFA) content on growth performance and hepatic morphology in liver in sole juveniles. Results revealed an inverse relationship between dietary FFA content and ability of fish to grow. Moreover, hepatic morphology analysis indicated an overall healthier status in hepatocytes of fish fed with low dietary FFA content. Dietary fatty acids must be esterified to glycerols seem an absolutely necessary requisite in sole, allowing a proper energy storing and its latter mobilisation to gain biomass.This work was supported by Interreg Project 0251_ECOAQUA_5_E, financed by the EDRF (European Regional Development Fund). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaquaLa utilizaci&oacute;n en la acuicultura de dietas inusuales con contenido lip&iacute;dico desequilibrados o tratamientos previos inadecuados puede resultar nocivo para los peces. Esta investigaci&oacute;n estudi&oacute; los efectos causados por distintas dietas con diferente contenido en &aacute;cidos grasos libres (FFA) en el crecimiento y la morfolog&iacute;a hep&aacute;tica en juveniles de lenguado. Los resultados revelaron una relaci&oacute;n inversa entre el contenido de FFA en la dieta y la capacidad de los peces para crecer. Por otra parte, el an&aacute;lisis de la morfolog&iacute;a hep&aacute;tica indic&oacute; un estado m&aacute;s saludable en los hepatocitos de los peces alimentados con una dieta baja en FFA . La esterificaci&oacute;n con glicerina de &aacute;cidos grasos es un requisito indispensable en lenguados, lo que permite un adecuado almacenamiento de energ&iacute;a y su posterior movilizaci&oacute;n para ganar biomasa.Este trabajo fue apoyado por el proyecto Interreg 0251_ECOAQUA_5_E , financiado por el FEDER (Fondo Europeo de Desarrollo Regional). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.</p

Rearing Senegalese sole (Solea senegalensis) growth juveniles at high stocking density

Stocking density and ration size are two major factors influencing aquaculture production. Their effects on growth and immune system were evaluated in Senegalese sole growth juveniles. Our results confirm that S. senegalensis is a species tolerating, in productive terms, to be cultivated under crowding conditions (30-45 kg m-2). Nevertheless, the studied biomarkers indicate physiological stress associated to high density, which might be affecting in last term to their inmuno-competence. Present work also assesses that sole response to high density is modulated by feeding ration. Finding the equilibrium between economically feasible, animal welfare and assumable risk factors seem to be the most reasonable option to cultivate this species nowadaysLa densidad de cultivo y el tamaño de ración son los dos principales factores que influyen en la producción acuícola. Sus efectos sobre el crecimiento y el sistema inmunológico fueron evaluados durante el crecimiento de juveniles de lenguado senegalés. Nuestros resultados confirman que S. senegalensis es una especie tolerante, en términos productivos, ser cultivado a altas densidades (30-45 kilogramos m-2). Sin embargo, los marcadores biológicos estudiados indican estrés fisiológico asociado a la alta densidad, que podría afectar en último término a su inmuno-competencia. El presente trabajo también muestra cómo la respuesta del lenguado a la alta densidad de cultivo está modulada por la ración de alimento. Por tanto, encontrando el equilibrio entre el bienestar animal, lo económicamente rentable y el riesgo asumible sería la opción más razonable para cultivar esta especie hoy día

Recent activities in the cultivation of sole (Solea senegalensis) in the El Centro IFAPA Toruño

El interés potencial del cultivo de Solea senegalensis se debe a que es una especie altamente demandada, se disponen de técnicas de cultivo a nivel larvario-juvenil y al buen crecimiento potencial. Se describen los hitos más importantes registrados así como los principales condicionantes de la producción

Metamorphosis Senegalese sole (Solea senegalensis Kaup, 1858) to low salinity: Production parameters and transcriptional analysis

&nbsp; The aim of this study was to analyze the effect of different salinities (10, 18, ¿¿27 and 36 ppt) on growth, survival and evolution of metamorphosis during larval development (from 10 to 31 days after hatching (DAH)). Moreover, we have determined the effects on different metabolic pathways by quantifying gene expression tg, hamp1, hsp90aa and gapdh1 .El lenguado senegal&eacute;s (Solea senegalensis Kaup, 1858) es una especie de gran importancia comercial en la acuicultura del sur de Europa. En Andaluc&iacute;a se ha apostado fuertemente por el cultivo en las aguas salobres de las marismas del Guadalquivir, donde la salinidad se sit&uacute;a en torno a 10 ppt. Sin embargo, poco se sabe sobre los efectos de bajas salinidades durante el cultivo larvario, particularmente en la metamorfosis. Estudios previos de nuestro grupo han evaluado la expresi&oacute;n de diferentes genes regulados durante la metamorfosis e implicados en la ruta de s&iacute;ntesis de hormonas tiroideas (tirogloblulina, tg), sistema inmune (hepcidin 1, hamp1), estr&eacute;s celular (hsp90aa), y metabolismo central (gapdh1) (Manchado et al., 2007; Manchado et al., 2008a; Manchado et al., 2008b; Ponce et al., 2010). El objetivo de este trabajo ha sido analizar el efecto de cuatro salinidades (10, 18, 27 y 36 ppt) sobre el crecimiento, supervivencia y evoluci&oacute;n de la metamorfosis durante el desarrollo larvario (desde 10 a 31 d&iacute;as tras la eclosi&oacute;n (DTE)). Ademas, se han determinado los efectos sobre diferentes rutas metab&oacute;licas mediante la cuantificaci&oacute;n de la expresi&oacute;n g&eacute;nica de tg, hamp1, hsp90aa y gapdh1. </p

High Tolerance of Senegalese sole (S. senegalensis Kaup, 1858) larvae to a low salinity culture medium.

&nbsp;Adjusting culture salinity to optimun physiological requirements is needed for the full aquaculture development of any species. Information concerning to salinity and larval cultivation conditions in sole does not exist at present. The possibility of rearing sole larvae in brackish waters with optimum results would constitute an advantage to industry, facilitating managing practices in hatchery facilities. The aim of present work was to analyze growth, survival anf feed ingestion of larvae reared at a salinity of 10 gl-1 (S=10 psu) from first feeding, 2 days after hatching (DAH) until completing metamorphosis (DAH 21).&nbsp;Adjusting culture salinity to optimun physiological requirements is needed for the full aquaculture development of any species. Information concerning to salinity and larval cultivation conditions in sole does not exist at present. The possibility of rearing sole larvae in brackish waters with optimum results would constitute an advantage to industry, facilitating managing practices in hatchery facilities. The aim of present work was to analyze growth, survival anf feed ingestion of larvae reared at a salinity of 10 gl-1 (S=10 psu) from first feeding, 2 days after hatching (DAH) until completing metamorphosis (DAH 21).</p

Dietary protein/carbohydrate ratio in low-lipid diets for Senegalese sole (Solea senegalensis, Kaup 1858) juveniles. Influence on growth performance, nutrient utilization and flesh quality

Four isoenergetic (21 kJ/g dry matter, DM) and isolipidic (65 g/kg DM) diets containing different crude protein/total carbohydrate (CHO) ratios: 60/26, 56/30, 52/34 and 48/38, were tested in 22 g Senegalese sole for 104 days. Apparent digestibility coefficients (ADC) were not affected by the treatments, and all groups presented extremely low starch ADC values (22.8%\u201336.5%). Replacement of dietary protein by CHO did not affect daily growth index (0.9\u20131.0), but significantly increased voluntary feed intake of fish. Regression analyses demonstrated that digestible protein content, rather than digestible energy, was the main dietary factor influencing such feeding activity (R2 = .952). A significantly increased feed conversion ratio was observed in sole fed increasing CHO contents. The dietary protein/CHO ratio did not influence whole-body composition. Sole fed the 48/38 diet showed the lowest efficiency in terms of N and energy utilization. PUFA were the most represented fatty acid fraction in fillet, regardless of the dietary protein/CHO ratio, mainly due to the high content of DHA. Senegalese sole increase feed intake under low dietary protein/CHO ratios to ensure an adequate N intake. Such compensatory mechanism seems to be triggered to satisfy a specific protein metabolic requirement for energy purposes as tissue accretion remained unchanged

Low salinity induces dysfunctional mouths without affecting the overall development in yolk sac larvae of Senegalese sole (S. senegalensis Kaup, 1858)

&nbsp; This research evaluated the influence of salinity on yolk sac larvae development of the flatfish Senegalese sole (Solea senegalensis Kaup). Larval notochord length, myotomal height and yolk sac volume were the studied development indicators. Opening mouth process and deformities also were analyzed.&nbsp; Esta investigaci&oacute;n evalu&oacute; la influencia de la salinidad sobre el desarrollo del saco vitelino en larvas del pez plano lenguado senegal&eacute;s (Solea senegalensis Kaup). La longitud de la notocorda, altura myotomal y volumen del saco vitelino fueron los indicadores de desarrollo estudiados. El proceso de apertura de la boca y las deformidades tambi&eacute;n fueron analizados.</p

Interactive effects of a high-quality protein diet and high stocking density on the stress response and some innate immune parameters of Senegalese sole Solea senegalensis

Amino acids (AA) regulate key metabolic pathways, including some immune responses. Therefore, this study aimed to assess whether an increased availability of dietary AA can mitigate the expected increase in plasma cortisol and metabolites levels due to high stocking density and its subsequent immunosuppression. Senegalese sole (Solea senegalensis) were maintained at low stocking density (LSD; 3.5 kg m−2) or high stocking density (HSD; 12 kg m−2) for 18 days. Additionally, both treatments were fed a control or a high protein (HP) diet (LSD, LSD HP, HSD and HSD HP). The HP diet slightly increased the levels of digestible indispensable AA, together with tyrosine and cysteine. HSD was effective in inducing a chronic stress response after 18 days of treatment since fish held at HSD presented higher plasma cortisol, glucose and lactate levels. Moreover, this increase in stress indicators translated in a decrease in plasma lysozyme, alternative complement pathway (ACP) and peroxidase activities, suggesting some degree of immunosuppression. Interestingly, while plasma glucose and lactate levels in HSD HP specimens decreased to similar values than LSD fish, plasma lysozyme, ACP and peroxidase activities increased, with even higher values than LSD groups for ACP activity. It is suggested that the HP diet may be used as functional feed since it may represent a metabolic advantage during stressful events and may counteract immunosuppression in sole