Use of tissue chromogranin A as chronic and acute stress marker in fish

Chromogranin A (CgA) has recently reported as stress marker in superior vertebrates. It is stored in granules of the chromaffin tissue and released to the bloodstream from the adrenal medulla and pituitary after stress situations. The objective of this work was to study the chromogranin A variation for acute and chronic stress in fish, aiming at determining if those proteins could be suitable stress markers. A chronic stress experiment was conducted consisting of two treatments, stressed and control meagres (Argyrosomus regius) for 6 months. The stressed groups were submitted to confinement and netting/chasing stress. The control group tanks were not disturbed along the experiment. A complementary acute stress challenge was performed exposing control fish to air for 3 min. Fish were sampled for blood, tissues and biometry. Plasma lactate and cortisol increased significantly after acute stress although glucose and proteins remained stable, and kidney cortisol and brain adrenaline were significantly higher. Kidney CgA decreased significantly in the acute stressed fish though brain CgA did not change. Final weight and length, growth and condition index were significantly lower in chronically stressed fish, though survival rate was not different between treatments. Plasma markers did not change significantly though kidney cortisol increased in chronically stressed fish. Brain noradrenaline was lower in chronically stressed fish. Both brain and kidney CgA concentrations decreased in stressed (chronic and acute) fish. Concluding, only kidney CgA and cortisol kept the same variation pattern in both stress types. Although cortisol concentrations in plasma and tissues have been widely studied, the tissue CgA concentrations related to stress have not still reported in fish. Initially, the depletion of kidney CgA could be considered as a chronic stress marker though it needs to be supported by future research.M. Herrera’s contract is supported by the Emergia Program (PAIDI 2020), from Junta de Andalucía. N. Salamanca’s pre-doc contract is cofinanced by the European Social Fund (FSE) through the call “Ayudas para contratos predoctorales para la formaci´on de doctores 2017” from the AEI. Funding for open access charge: Universidad de Huelva / CBUA

First releases of hatchery‑produced Senegal sole (Solea senegalensis), brill (Scophthalmus rhombus), and wedge sole (Dicologoglossa cuneata) juveniles in the South‑western Spanish coast

Primeras y únicas repoblaciones con peces en el litoral de HuelvaThe regression of fisheries in the Gulf of Cadiz is evident since current fish catches are 33% of that 30 years before. Consequently, some initiatives for the replenishment of exhausted wild stocks are welcome. The objective of the present work is to describe and analyze the results coming from the first flatfish stock enhancements in Andalusia. A total of 3189 fish from three flatfish species: Senegal sole (Solea senegalensis Kaup), wedge sole (Dicologlossa cuneata Moreau), and brill (Scophthalmus rhombus Linnaeus) were tagged and released. Several variables were calculated through the data analysis of recovered fish. Some variables were calculated only for Senegal soles since wedge sole and brill recaptures were not significant. The Senegal sole recapture rate was 2.71±0.72, similar to other published data, the recapture rates for bigger fish being higher though not significant. No significant differences were detected for distance, time, growth or recapture rate among initial Senegal sole sizes. Around 80% of recaptures were registered within 15 weeks after release. The results show that it is possible the release and recovery of tagged Senegal soles in the Gulf of Cadiz. Future long-term programs on stock enhancement could help to determine the effects on fisheries and recover stocks.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study has been financed by the Consejería de Agricultura, Ganadería, Pesca y Desarrollo Sostenible of the Junta de Andalucia. M. Herrera’s post-doc contract is supported by the National Institute of Agricultural Research and the European Social Fund (INIA-FSE). Funding for open access charge: Universidad de Huelva / CBUA

Bromatological composition of palm kernel meal according to its origin and production periods potential use of palm kernel meal in animal feed

Ecuador has a variety of agroindustrial by-products, which can be used in animal feed, although their nutritional values are often unknown. The objective of this study was to evaluate bromatological composition of palm kernel cake (PKC) in samples from two palm oil extraction plants in two areas (Quevedo and Santo Domingo) and two production periods (August and September). Random samples were taken weekly with two repetitions for a total of 64 samples. Dry matter (DM), ash, organic matter (OM), crude protein (CP), ether extract (EE), crude fibre (CF), nitrogen-free extract (NFE), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), calcium, phosphorus, crude energy (CE) and metabolisable energy (ME) were determined. OM (62.92%) and EE (10.10%) content were higher at the Quevedo plant, while CF (23.84%) and ADL (24.66%) were higher at the Santo Domingo plant. The sampling period affected DM (98.58%), CF (23.98%) and ADL (23.78%) content, which were higher in September, while EE (10.87%) and phosphorus (0.44%) were higher in August. For CP, NFE, NDF, ADF, ash, calcium, CE and ME, interaction was observed between the two factors studied. It was concluded that most of the parameters analysed depend on the place of origin or the extraction season, or interaction between the two factors.The research was supported by the Graduate Department of the State Technical University of Quevedo, with supported from Fourth Notary of the canton Quevedo Los Rios, Ecuador and INIA-FS

Rendimiento productivo de la vieja colorada (Mesoheros festae) alimentada con dietas basadas en torta de palmiste durante la etapa juvenil

Background: The increasingly aquaculture development have favored the searching of new protein sources for fish feeding. Goals: 1) trying to present the first data on the culture of an important commercial species in Ecuador, 2) replacing the protein source for feeding in order to minimize the global problem of the fish-based meals in aquaculture. Methods: Guayas cichlid juvenile fish were submitted to 4 feeding treatments: 0%, 4%, 8% and 12% palm cake replacement for 30 days. Several zootechnnical indexes were calculated and analyzed at the end of the experimental culture, as well as the feed proximal composition. Results: The inclusion up to 8% palm cake did not affect the digestibility coefficients of dry matter, gross protein or gross energy.  No differences were found in final weight, growth rate, food conversion rate, protein efficiency rate and productive value of the protein among 0, 4 and 8% palm meal content treatments. As the percentage of palm kernel meal in the diets was increased, the food conversion rate decreased. Increasing palm meal in diets decreased costs.  Conclusions: The productive performance was not affected by the palm cake replacement in diets up to 8% with palm meal, and deriving in lower feed production costs.Antecedentes: La expansión de la acuicultura ha favorecido el estudio de fuentes de proteínas para la alimentación de peces. Objetivos: 1) tratar de presentar los primeros datos sobre el cultivo de una importante especie comercial en Ecuador, 2) reemplazar la fuente de proteína para la alimentación con el fin de minimizar el problema global de las comidas a base de harina de pescado en la acuicultura. Métodos: Juveniles de vieja colorada fueron sometidos a 4 tratamientos de alimentación: 0%, 4%, 8% y 12% de sustitución por torta de palmiste durante 30 días. SE calcularon y analizaron varios índices zootécnicos al final del cultivo experimental, así como la composición proximal de las dietas experimentales. Resultados: La inclusión de hasta un 8% de torta de palmiste no afectó a los coeficientes de digestibilidad de materia seca, proteína bruta o energía bruta. No se encontraron diferencias en peso final, tasa de crecimiento, tasa de eficiencia de la proteína y valor productivo de la proteína entre los tratamientos de 0, 4 y 8% de contenido en torta de palmiste. Conforme creció el porcentaje de torta de palmiste en la dieta aumentó la tasa de conversión del alimento. El aumento de la torta de palmiste en las dietas redujo los costes.  Conclusiones: El rendimiento productivo no se vio afectado por la sustitución de dietas incluyendo hasta un 8% por torta de palmiste, y derivando en menores costes de producción

Influence of Dietary Lipids and Environmental Salinity on the n-3 Long-Chain Polyunsaturated Fatty Acids Biosynthesis Capacity of the Marine Teleost Solea senegalensis

Fish vary in their ability to biosynthesise long-chain polyunsaturated fatty acids (LC-PUFA) depending upon the complement and function of key enzymes commonly known as fatty acyl desaturases and elongases. It has been reported in Solea senegalensis the existence of a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid (DHA) from eicosapentaenoic acid (EPA), which can be modulated by the diet. The present study aims to evaluate the combined effects of the partial replacement of fish oil (FO) with vegetable oils and reduced environmental salinity in the fatty acid composition of relevant body compartments (muscle, hepatocytes and enterocytes), the enzymatic activity over α-linolenic acid (ALA) to form n-3 LC-PUFA through the incubation of isolated hepatocytes and enterocytes with [1-14C] 18:3 n-3, and the regulation of the S. senegalensis fads2 and elovl5 in the liver and intestine. The presence of radiolabelled products, including 18:4n-3, 20:4n-3 and EPA, provided compelling evidence that a complete pathway enabling the biosynthesis of EPA from ALA, establishing S. senegalensis, has at least one Fads2 with ∆6 activity. Dietary composition prevailed over salinity in regulating the expression of fads2, while salinity did so over dietary composition for elovl5. FO replacement enhanced the proportion of DHA in S. senegalensis muscle and the combination with 20 ppt salinity increased the amount of n-3 LC-PUFA in hepatocytes

Cross-border cooperation for the development of good sanitary practices in marine aquaculture

This documental about BONAQUA project summarizes the activities that has been developed in the context of this: Research and Development, Formation, Improvement of facilities, management and coordination and communication.Video sobre el proyecto BONAQUA que resume las actividades que se desarollan en el marco de &eacute;ste sobre Investigaci&oacute;n y desarrollo, Formaci&oacute;n, Mejora de instalaciones, Gesti&oacute;n y coordinaci&oacute;n y Comunicaci&oacute;n.</p

Sperm production and quality in brill Scophthalmus rhombus L.: Relation to circulating sex steroid levels

The aims of the present study were to characterize sperm quality and to quantify seasonal changes in sexual hormone (testosterone [T], 11-ketotestosterone [11-KT] and 17,20β-dihydroxypregn-4-en-3-one [17,20β-P]) levels in male brill (Scophthalmus rhombus) plasma, as well as to test a more intensive sampling strategy to establish relationships between sex steroid levels and sperm production parameters. Sperm concentration ranged from 0. 5 to 3. 1 × 109 spermatozoa mL-1, and changes in sperm quality parameters depending on sampling date were observed. Plasma sexual steroid levels remained high and changed in parallel during the spawning season and afterwards decreased to very low levels in summer. The analysis of annual changes of 11-KT and T ratios suggests that 11-KT can be the main circulating androgen for stimulating spermatogenesis in S. rhombus and that T could be involved in the beginning of spermatogenesis through the positive feedback on brain-pituitary-gonad axis. Finally, daily 11-KT and T levels showed similar patterns of variation in males sampled, whereas 17,20β-P amounts showed somewhat opposite trends. These differences could be related with the different role of androgens and progestin during the spermatogenesis. © 2012 Springer Science+Business Media B.V.This work has been founded by the project INIA TRT2006-00011-C02-01, “Establecimiento de una metodología de reproducción artificial para la obtención de puestas de calidad en el parracho (Scophthalmus rhombus).Peer Reviewe

Aquaculture developments and cross-border cooperation in IFAPA

This documentary seeks to highlight the technological improvements in infrastructure and laboratories and scientific advances made within ECOAQUA project, in IFAPA ¿Agua del Pino¿Este documental pretende dar a conocer las mejoras tecnológicas en las infraestructuras y laboratorios y los avances científicos logrados en el Centro IFAPA Agua del Pino en el seno de proyecto ECOAQU