Cuantificación y alteraciones histopatológicas producidas por concentraciones subletales de cobre en Fundulus heteroclitus

25 páginas.[EN] Fed and starved Fundulus heteroclitus specimens were exposed for 30 days to sublethal copper concentrations (800 ?g Cu2+/L). The accumulation of copper and histopathological effects on the liver and gills were studied. In both fed and starved specimens, the liver showed a progressive copper accumulation during the experimental period (from 2 to 30 days), with higher levels of copper in the liver of starved fish. Copper accumulation was also detected in the gills, and the specimens exposed to copper for 15 to 30 days (both fed and starved) showed significant differences (P < 0.005) with respect to the control group and the 2-day treated fishes. The main histopathological alterations were: vacuolization of hepatic parenchyma, desquamation of gill epithelia, lamellar telangiectasia, as well as hepatic and branchial necrosis. The results of this paper provide evidence that the nutritional status of the fish has great importance in modifying its response to sublethal copper effects.[ES]Ejemplares de Fundulus heteroclitus alimentados y mantenidos en inanición fueron expuestos a concentraciones subletales de cobre (800 µg Cu2+/L) durante un periodo de 30 días. Se estudió la acumulación de cobre, así como las alteraciones histopatológicas producidas en las branquias y en el hígado. El hígado, tanto en los organismos alimentados como en los mantenidos en ayunas, presentó acumulación progresiva hasta los 30 días, con mayores niveles en ejemplares sometidos al ayuno. Por otro lado, en las branquias se detectó también acumulación de cobre, presentando el grupo de organismos expuestos de 15 a 30 días (alimentados y sometidos a inanición) diferencias significativas (P < 0.005) con respecto al grupo control y los tratados durante 2 días. Las principales alteraciones histopatológicas fueron: vacuolización del parénquima hepático, descamación del epitelio branquial, telangiectasia lamelar, así como necrosis branquial y hepática. Los resultados obtenidos en el presente trabajo muestran la importancia del estado nutricional de peces, como modificador de la respuesta de los mismos a los efectos subletales producidos por la exposición a cobre.Peer reviewe

Potential risk of Artemia sp as a transmission vector of lymphocystis disease virus (LCDV)

4 páginas, 1 figura. XI Congreso Nacional de Acuicultura (Vigo, 24-28 septiembre 2007). Ed. Antonio Cerviño Eiroa, Alejandro Guerra Díaz y Carmen Pérez Acosta.[EN] Cysts and naupliis of Artemia sp. were analysed. Specific nested-PCR revealed lymphocystis disease virus (LCDV) genome. Infective viral particle has been observed by CPE development in inoculated cell cultures. Viral genome was found by in situ hybridization in nauplii and adults of natural infected artemia, as in nauplii of bath challenged artemia. No morphological damages have been observed. Artemia is a bio-accumulator of fish pathogens, with a possible role as environmental reservoir of fish pathogens. These results have shown the risk of artemia as a source of viral pathogens to fish larvae.[ES] En el presente trabajo se han realizado estudios virológicos en distintos lotes de quistes comerciales de artemias utilizados como alimento de larvas de peces marinos en piscifactorías. Mediante nested-PCR se ha detectado genoma del virus de linfocistis (LCDV) en homogeneizados de quistes y nauplios de artemia. La existencia de partículas víricas infectivas en estos homogeneizados se ha demostrado mediante la aparición de efectos citopáticos en cultivos celulares. Los ensayos de hibridación in situ han demostrado la existencia del LCDV en artemias infectadas naturalmente, así como en artemias inoculadas mediante baño, sin observarse alteraciones morfológicas. Las artemias actúan por tanto como bioacumuladores, pudiendo desempeñar un papel importante como reservorios ambientales de patógenos de peces. Estos resultados ponen de manifiesto el riesgo potencial de las artemias como fuente de patógenos víricos en estadios larvarios.Irene Cano es contratada postdoctoral en el ICMAN.CSIC dentro del Fondo social europeo- I3P-CSIC, en el marco del proyecto AGL2006-17777-C03-02/ACU (IP: Carmen Sarasquete).Peer reviewe

Contrasting outcomes of Vibrio harveyi pathogenicity in gilthead seabream, Sparus aurata and European seabass, Dicentrachus labrax

Vibrio harveyi has been reported as the dominant heterotrophic bacterial species in western Mediterranean coastal areas during warm seasons, and is recognized as an economically significant pathogen for the aquaculture industry. The present work aimed to evaluate the pathogenicity of a V. harveyi strain isolated from ascitic fluid collected from cultured gilthead seabream and then used in a challenge experiment involving the two most important fish species in Mediterranean aquaculture: gilthead seabream, Sparus aurata and European seabass, Dicentrarchus labrax. The ascitic fluid from diseased juvenile seabreams, previously vaccinated against Photobacterium damselae and Vibrio anguillarum, was extracted and bacteria cultivated for isolation and characterization. Additionally, different tissues were sampled for histological evaluation and description. Significant histopathological responses were observed in hepatic and mucosal tissues. One of the strains isolated from ascitic fluid, IRTA 17-43, was selected for a bacterial challenge. Additionally, the attenuation of virulence through sequential passage of the strain on solid media was also assessed. In parallel, a co-habitation trial was performed in order to evaluate the possible transfer of the bacteria between injected and healthy individuals. Pathogenicity trials in gilthead seabream resulted in only 25% mortality when injected with 107 CFU mL−1, whereas, for European seabass, a mortality of 95% was recorded, with clear signs of vibriosis. When passed sequentially on solid media, the strain IRTA-17-43 showed a decrease of 35% in cumulative mortality for European seabass. No apparent transmission of the pathogen occurred during the co-habitation trial for both species. In conclusion, although few external signs of V. harveyi are observed in vaccinated carriers, internal effects of the infection were clear and severe. Although no horizontal transfer of infection was observed, the risk of occurrence between carriers and immunosuppressed individuals or between different species should be considered. This further validates that the establishment of a good health management system within fish farms is of major importance in order to avoid the onset of disease outbreaks.info:eu-repo/semantics/acceptedVersio

Effect of dietary vitamin A on Senegalese sole (Solea senegalensis) skeletogenesis and larval quality

16 páginas, 12 figuras, 4 tablas.The effects of different levels of vitamin A (VA) in Senegalese sole larval performance and development were evaluated by means of a dietary dose–response experiment using enriched Artemia metanauplii as a carrier of this micronutrient. Larvae were fed from 6 to 27 days post hatch (dph) with enriched Artemia containing graded levels of total VA (1.3, 2.1, 4.5 and 12.9 µg VA mg− 1 DW). The content of VA in live prey directly affected its accumulation in larvae and early juveniles. Retinyl palmitate accumulated during larval ontogeny, whereas retinol showed the opposite trend, decreasing from hatching until 41 dph and then remaining constant until the end of the study. In metamorphic larvae (10 and 15 dph), VA did not affect the number of thyroid follicles or the intensity of the immunoreactive staining of T3 and T4. However, at older stages of development (post-metamorphic larvae: 20, 30, 41 and 48 dph), VA decreased the number of thyroid follicles but increased their mean size and enhanced T3 and T4 immunoreactive staining. A dietary excess of VA did not affect either larval performance in terms of growth and survival or the maturation of the digestive system. However, the most remarkable impact of this morphogenetic nutrient was detected during skeletal morphogenesis. Dietary VA accelerated the intramembranous ossification of vertebral centrums, which led to the formation of a supranumerary haemal vertebra and a high incidence of fused and compressed vertebrae in fish fed 2.1, 4.5 and 12.9 mg VA mg− 1 DW. In addition, VA also affected those structures from vertebrae and caudal fin formed by chondral ossification, leading to defects in their shape and fusions with adjacent skeletal elements. In particular, the caudal fin was the region most affected by the dietary treatments. In order of importance, the bones with more developmental anomalies were the modified neural and haemal spines, epural, hypurals and parahypural. The impact of systemic factors such as thyroidal hormones in skeletogenesis should not be neglected since present results revealed that an excess of dietary VA affected the levels of T3 and T4, which might have affected bone formation and remodelling, leading to skeletal deformities.This work was funded by the Ministry of Education and Culture (MEC) of the Spanish Government (project AGL2005-02478).Peer reviewe

Unveiling the effect of dietary essential oils supplementation in Sparus aurata gills and its efficiency against the infestation by Sparicotyle chrysophrii

A microencapsulated feed additive composed by garlic, carvacrol and thymol essential oils (EOs) was evaluated regarding its protective effect in gills parasitized by Sparicotyle chrysophrii in Sparus aurata. A nutritional trial (65 days) followed by a cohabitation challenge with parasitized fish (39 days) were performed. Transcriptomic analysis by microarrays of gills of fish fed the EOs diet showed an up-regulation of genes related to biogenesis, vesicular transport and exocytosis, leukocyte-mediated immunity, oxidation–reduction and overall metabolism processes. The functional network obtained indicates a tissue-specific pro-inflammatory immune response arbitrated by degranulating acidophilic granulocytes, sustained by antioxidant and anti-inflammatory responses. The histochemical study of gills also showed an increase of carboxylate glycoproteins containing sialic acid in mucous and epithelial cells of fish fed the EOs diet, suggesting a mucosal defence mechanism through the modulation of mucin secretions. The outcomes of the in vivo challenge supported the transcriptomic results obtained from the nutritional trial, where a significant reduction of 78% in the abundance of S. chrysophrii total parasitation and a decrease in the prevalence of most parasitic developmental stages evaluated were observed in fish fed the EOs diet. These results suggest that the microencapsulation of garlic, carvacrol and thymol EOs could be considered an effective natural dietary strategy with antiparasitic properties against the ectoparasite S. chrysophrii.info:eu-repo/semantics/publishedVersio

Unveiling the effect of dietary essential oils supplementation in Sparus aurata gills and its efficiency against the infestation by Sparicotyle chrysophrii

A microencapsulated feed additive composed by garlic, carvacrol and thymol essential oils (EOs) was evaluated regarding its protective effect in gills parasitized by Sparicotyle chrysophrii in Sparus aurata. A nutritional trial (65 days) followed by a cohabitation challenge with parasitized fish (39 days) were performed. Transcriptomic analysis by microarrays of gills of fish fed the EOs diet showed an up-regulation of genes related to biogenesis, vesicular transport and exocytosis, leukocyte-mediated immunity, oxidation–reduction and overall metabolism processes. The functional network obtained indicates a tissue-specific pro-inflammatory immune response arbitrated by degranulating acidophilic granulocytes, sustained by antioxidant and anti-inflammatory responses. The histochemical study of gills also showed an increase of carboxylate glycoproteins containing sialic acid in mucous and epithelial cells of fish fed the EOs diet, suggesting a mucosal defence mechanism through the modulation of mucin secretions. The outcomes of the in vivo challenge supported the transcriptomic results obtained from the nutritional trial, where a significant reduction of 78% in the abundance of S. chrysophrii total parasitation and a decrease in the prevalence of most parasitic developmental stages evaluated were observed in fish fed the EOs diet. These results suggest that the microencapsulation of garlic, carvacrol and thymol EOs could be considered an effective natural dietary strategy with antiparasitic properties against the ectoparasite S. chrysophrii.info:eu-repo/semantics/publishedVersio

Comparative gene expression of gonadotropins (FSH and LH) and peptide levels of gonadotropin-releasing hormones (GnRHs) in the pituitary of wild and cultured Senegalese sole (Solea senegalensis) broodstocks

12 páginas, 8 figuras, 2 tablas.The Senegalese sole (Solea senegalensis) is a valuable flatfish for aquaculture, but it presents important reproductive problems in captivity. Spawning is achieved by wild-caught breeders but cultured broodstocks fail to spawn spontaneously and, when they do, eggs are unfertilized. To gain knowledge on the physiological basis underlying this reproductive dysfunction, this study aimed at analyzing comparative hormone levels between wild and cultured broodstocks at the spawning season. The Senegalese sole gonadotropin (GTH) subunits, FSHβ, LHβ and GPα, were cloned and qualitative (in situ hybridization) and quantitative (real-time PCR) assays developed to analyze pituitary GTH gene expression. In females, FSHβ and GPα mRNA levels were higher in wild than in cultured broodstocks, whereas in males all three subunits were highest in cultured. By ELISA, three GnRH forms were detected in the pituitary, displaying a relative abundance of GnRH2 > GnRH1 > GnRH3. All GnRHs were slightly more abundant in wild than cultured females, whereas no differences were observed in males. Plasma levels of vitellogenin and sex steroids were also analyzed. Results showed endocrine differences between wild and cultured broodstocks at the spawning period, which could be related to the endocrine failure of the reproductive axis in cultured breeders.This research was funded by the Spanish Ministry of Education and Science (MEC) (AGL2006-13777-C01), the Ministry of Agriculture, Fisheries and Food (MAPA) (JACUMAR, II National Plan for the Cultivation of Sole) and the Regional Government of Galicia (PGIDIT06RMA004E). J.M. Guzmán received a FPI fellowship from the MEC. J.B. Ortiz-Delgado was supported by the “Ramón y Cajal” program (MEC, Spain).Peer reviewe

Unveiling the effect of dietary essential oils supplementation in Sparus aurata gills and its efficiency against the infestation by Sparicotyle chrysophrii

Altres ajuts: Industrial PhD program of Generalitat de Catalunya (Doctorats Industrials) and TECNOVIT-FARMFAES S.L. (No. 2017 DI 017)A microencapsulated feed additive composed by garlic, carvacrol and thymol essential oils (EOs) was evaluated regarding its protective effect in gills parasitized by Sparicotyle chrysophrii in Sparus aurata. A nutritional trial (65 days) followed by a cohabitation challenge with parasitized fish (39 days) were performed. Transcriptomic analysis by microarrays of gills of fish fed the EOs diet showed an up-regulation of genes related to biogenesis, vesicular transport and exocytosis, leukocyte-mediated immunity, oxidation-reduction and overall metabolism processes. The functional network obtained indicates a tissue-specific pro-inflammatory immune response arbitrated by degranulating acidophilic granulocytes, sustained by antioxidant and anti-inflammatory responses. The histochemical study of gills also showed an increase of carboxylate glycoproteins containing sialic acid in mucous and epithelial cells of fish fed the EOs diet, suggesting a mucosal defence mechanism through the modulation of mucin secretions. The outcomes of the in vivo challenge supported the transcriptomic results obtained from the nutritional trial, where a significant reduction of 78% in the abundance of S. chrysophrii total parasitation and a decrease in the prevalence of most parasitic developmental stages evaluated were observed in fish fed the EOs diet. These results suggest that the microencapsulation of garlic, carvacrol and thymol EOs could be considered an effective natural dietary strategy with antiparasitic properties against the ectoparasite S. chrysophrii

Ongrowing European fish species with feeds formulated with a by-product derived from cereal processing

Trabajo presentado en el congreso Aquaculture Europe 2023: Balanced Diversity in Aquaculture Development celebrado en Viena (Austria) entre el 18 y el 21 de septiembre de 2023.The cereal industry generates large amounts of residual by-products with high potential as feed ingredient for aquafeeds. Such raw materials could help to substitute protein and lipids from less sustainable sources such as soy concentrate, wheat flour or oils and reduce the competitiveness between the production of aquafeeds and the use of food for human consumption. In this study, one of these by-products, corn gluten feed, has been tested in dose-response experiments as ingredients in on-growing feeds for two European species (greater amberjack, Seriola dumerili; gilthead seabream, Sparus aurata). The final aim was to examine to what extent this more-sustainable and low-cost product can be used as alternate ingredient for fish feeds.Project SUSTAINFEED, EIT Food 21168, Co-funded by the European Union

Medicinal Plant Leaf Extract From Sage and Lemon Verbena Promotes Intestinal Immunity and Barrier Function in Gilthead Seabream (Sparus aurata)

The inclusion of a medicinal plant leaf extract (MPLE) from sage (Salvia officinalis) and lemon verbena (Lippia citriodora), rich in verbascoside and triterpenic compounds like ursolic acid, was evaluated in gilthead seabream (Sparus aurata) fed a low fishmeal-based diet (48% crude protein, 17% crude fat, 21.7 MJ kg-1, 7% fishmeal, 15% fish oil) for 92 days. In particular, the study focused on the effect of these phytogenic compounds on the gut condition by analyzing the transcriptomic profiling (microarray analysis) and histological structure of the intestinal mucosa, as well as the histochemical properties of mucins stored in goblet cells. A total number of 506 differentially expressed genes (285 up- and 221 down-regulated) were found when comparing the transcriptomic profiling of the intestine from fish fed the control and MPLE diets. The gut transcripteractome revealed an expression profile that favored biological mechanisms associated to the 1) immune system, particularly involving T cell activation and differentiation, 2) gut integrity (i.e., adherens and tight junctions) and cellular proliferation, and 3) cellular proteolytic pathways. The histological analysis showed that the MPLE dietary supplementation promoted an increase in the number of intestinal goblet cells and modified the composition of mucins’ glycoproteins stored in goblet cells, with an increase in the staining intensity of neutral mucins, as well as in mucins rich in carboxylated and weakly sulfated glycoconjugates, particularly those rich in sialic acid residues. The integration of transcriptomic and histological results showed that the evaluated MPLE from sage and lemon verbena is responsible for the maintenance of intestinal health, supporting gut homeostasis and increasing the integrity of the intestinal epithelium, which suggests that this phytogenic may be considered as a promising sustainable functional additive for aquafeeds.info:eu-repo/semantics/publishedVersio