4629 research outputs found
Sort by
Bivariate and multivariate analyses of allometric growth in larvae of farmed meagre (Argyrosomus regius): an integrated approach to define growth stages and ontogenetic transitions
Get PDFFish larval rearing represents a critical stage due to the extreme fragility of larvae, small size, and specific nutritional needs during rapid growth. Successful larviculture requires understanding ontogenetic changes to adapt rearing practices and optimize larval development. Thus, the objective of this study was to describe the ontogeny and allometric growth of hatchery-reared meagre (Argyrosomus regius) larvae from hatching to the juvenile stage by combining bivariate and multivariate morphometric analyses. Results showed that the early development of meagre was divided into three distinct growth stages marked by functional transitions. The first stage (≤3.21 mm standard length, SL) coincided with yolk absorption, onset of exogenous feeding, swim bladder inflation, and accelerated cranial development, particularly in the operculum and eye–operculum region, supporting respiration and feeding. The second stage (3.21–5.35 mm SL) was characterized by near-isometric cranial growth and positive allometry in trunk and caudal traits, reflecting gastrointestinal maturation and enhanced swimming capacity. The third stage (>5.35 mm SL) included substantial cranial and caudal differentiation, such as jaw ossification, fin formation, and sensory refinement, particularly visual enhancement, enabling efficient prey detection and capture. Principal component analysis identified two inflection points (3.21 and 5.35 mm SL), marking developmental transitions from cranial growth to locomotor enhancement and the onset of juvenile traits. These morpho-functional transitions highlight critical windows for aquaculture, such as ensuring optimal light conditions and swim bladder inflation during the first stage, providing highly digestible diets and adequate buoyancy during the second, and optimizing live prey presentation and water clarity during the third. This study showed that while traditional allometric approaches examine isolated characters relative to organism size, multivariate allometry offers comprehensive understanding of how multiple larval body regions scale together during size changes. In conclusion, this integrated approach highlights coordinated allometric transitions during meagre larval development, providing a framework to identify critical growth phases and refine rearing protocols for improved larval performance and survival.The author(s) declare that financial support was received for the research and/or publication of this article. This work was co-funded by IRTA’s own funds and the Project RTI2018-095653-R-I00 funded by the Ministerio de Ciencia, Innovación y Universidades (Spain).info:eu-repo/semantics/publishedVersio
Spectroscopic Analysis of Proximal Leaves as a Method for Studying Nectarine Ripening
Get PDFTraditional methods for fruit quality assessment are labor-intensive, destructive, and result in the loss of marketable
produce. Spectroscopy, especially near-infrared (NIR) and mid-infrared (MIR), has helped in the analysis of fruit quality, despite
being nondestructive, as it can leave some marks on the fruit. This study investigates the potential of NIR and MIR spectroscopy for
monitoring nectarine ripening through the analysis of proximal leaves, leveraging their biochemical and physiological changes during
ripening as a practical and truly noninvasive alternative to predict key fruit attributes. Spectral data were analyzed using ANOVASimultaneous Component Analysis (ASCA) to determine the key factors influencing spectral variability. The results indicated that
the evolution of the spectra was the primary contributor to spectral changes, reflecting physiological dynamics during fruit ripening.
Partial Least Squares (PLS) regression models were employed to predict key fruit properties (weight, firmness, sugar content, pH
and acidity). The models showed acceptable performance for indirect prediction with R2CV values ranging from 0.4 to 0.7, RPD
values from 1.41 to 1.88, and RER values from 5.56 to 10.21. Predictions were good for nectarine properties like weight and
firmness, with leaf spectra effectively predicting these fruit characteristics, though predictions for acidity and pH were less robust.
Key findings suggest that combining spectral data from both sides of the leaf provides models with good performance, offering a
practical noninvasive alternative to destructive fruit quality analysis methods and providing valuable insights for precision agriculture.
This approach has great potential to redefine ripening assessments in fruit production and monitoring practices.Grants PID2019-104269RR-C33 funded by MICIU/AEI/10.13039/501100011033. Grants URV Martí i Franques− Banco Santander (2021PMF-BS-12; Ezenarro, J.) and URV Martí i Franques− IRTA (2020PMF−PIPF-6; Garcia-Pizarro, Á).info:eu-repo/semantics/publishedVersio
The orientation and oviposition choices of Plutella xylostella and its parasitoid Diadegma semiclausum on a range of Brassica plants
Get PDFPlants emit volatile organic compounds (VOCs) that mediate interactions with organisms in the surrounding community, such as herbivorous insects and their natural enemies. Understanding on plant attractiveness for insects can help to design intercropping systems, such as trap crops. Here we present the results of laboratory tests designed to compare the attractiveness of cabbage (Brassica oleracea), broccoli (Brassica oleracea var. italica), turnip (Brassica rapa var. rapa), and yellow rocket (Barbarea stricta) to Plutella xylostella and its natural enemy, the parasitoid wasp, Diadegma semiclausum. Plants were selected based on the results of a cabbage intercropping field experiment and a screening of VOC emissions of a variety of landrace Brassica plants both intact and damaged by P. xylostella. Plutella xylostella selected turnip and B. stricta over cabbage and broccoli in oviposition tests. Reproductive success of Diadegma semiclausum in oviposition tests was higher on host larvae feeding on turnip plants compared to cabbage and broccoli, while B. stricta was not tested. According to principal component analyses, volatile blends emitted by turnip and B. stricta differed from each other as well as from other plants, while volatile blends emitted by cabbage and broccoli were more similar, both when intact and when damaged by P. xylostella.info:eu-repo/semantics/publishedVersio
Monitoring the texture of high-moisture extrudates in the cooling die of an extruder using near-infrared spectroscopy
Get PDFHigh-moisture extrusion processing (HMEP) is used to produce high-moisture extrudates (HME) with fibrous textures that mimic animal meat. However, many factors affect the final product, and industries require in-line control tools to monitor and optimise the process. This study aims to evaluate the feasibility of using near-infrared spectroscopy (NIRS) to monitor HMEP in the cooling die of an extruder through the prediction of the textural properties of the final product. Different strategies to minimise the temperature effects over the spectra and different modelling approaches were evaluated. To do so, NIR spectra were acquired in the cooling die of the extruder during HMEP at different cooling die temperatures (10–30 °C) and flow rates (10.0, 12.5, 16, 19.5, and 22.0 g/min). Then, the moisture content and textural properties of the final HME were determined physicochemically. Various correction techniques were used to minimise the effects of temperature on the spectra and improve the in-line prediction accuracy of the extrudates' textural properties. Results showed that, with adequate preprocessing, the textural properties could be estimated using both partial least squares regression (PLSR) and principal component regression. Using PLSR models, the lowest predictive errors obtained were 0.87 N for transversal cut force, 9.15 N for hardness, and 7.90·10−3 for springiness. However, the data proved to be insufficient to train a convolutional neural network properly. Although more experimental work is needed, NIRS and chemometric techniques demonstrate potential for monitoring HMEP in the cooling die, enabling in-line optimisation of this process.Project grant [PID2021-122285OR-I00] funded by MICIU/AEI/10.13039/501100011033 and by ERDF/EU. First author's grant [PRE2022-103798] funded by MICIU/AEI/10.13039/501100011033 and ESF+. Acknowledgements are extended to the consolidated research group (2021 SGR 00461) and CERCA program from Generalitat de Catalunya.info:eu-repo/semantics/publishedVersio
Growth performance, phytate degradation, and tibia characteristics of broiler chickens fed pelleted diets with varying feed particle sizes and phytase levels
Get PDFThe objective was to investigate the effects of feed particle size and microbial phytase supplementation of pelleted diets on growth performance, myo-inositol hexakisphosphate (InsP6) degradation, and tibia characteristics
in broiler chickens. Ross 308 broilers were housed in 56 floor pens in groups of 42, and seven pens were allocated
to one of eight dietary treatments to measure the performance data on day 38 of age. From day 21 to 26, six birds
from each floor pen were moved to metabolism units with the same distribution of treatments for digestibility
and bone measurements. For the starter phase, two diets with fine or coarse particle size (429 or 657 µm mean
particle size, determined after feed processing by wet sieving) were formulated and added with 500 FTU phytase/kg. For the grower and finisher phase, diets were arranged with two particle sizes (fine and coarse, 434 or
729 µm) and four phytase levels (0, 300, 600, and 1,200 FTU/kg). No significant interactions between particle
size and phytase were determined. Prececal InsP6 disappearance and P digestibility were higher with fine than
coarse particles, indicating that coarse grinding of rapeseed meal may not benefit birds. Increasing phytase
supplementation increased ADG, ADFI, prececal InsP6 disappearance and P digestibility, tibia ash, and tibia
breaking strength. Under the conditions of this study, birds were sufficiently supplied with P at a total P level of
4.0 g/kg and phytase supplementation of 1,200 FTU/kg. Renouncement of feed phosphate in the grower and
finisher phase was possible without impaired performance.The authors gratefully acknowledge the experimental station’s staff and the laboratory members of IRTA for animal care and sample preparation and analysis. We also thank the staff of the Department of Animal Nutrition at the University of Hohenheim for sample analysis. This study was financially supported by BASF SE (Ludwigshafen, Germany). Dieter Feuerstein is an employee of BASF SE.info:eu-repo/semantics/publishedVersio
Retrospective investigation of porcine circoviruses in cases of porcine dermatitis and nephropathy syndrome
No full textinfo:eu-repo/semantics/publishedVersio
Protection Against Transplacental Transmission of a Highly Virulent Classical Swine Fever Virus Two Weeks After Single-Dose FlagT4G Vaccination in Pregnant Sows
Get PDFBackground/Objectives: Classical swine fever (CSF) continues to challenge global eradication efforts, particularly in endemic regions, where pregnant sows face heightened risks of vertical transmission following exposure to CSFV. Methods: This study evaluates the early protective efficacy of FlagT4G, a novel live attenuated DIVA-compatible vaccine. Pregnant sows were vaccinated at mid-gestation and challenged 14 days later with a highly virulent CSFV strain. Results: FlagT4G conferred complete clinical protection, preventing both maternal viremia and transplacental transmission. No CSFV RNA, specific antibodies, or IFN-α were detected in fetal samples from vaccinated animals. In contrast, unvaccinated sows exhibited clinical signs, high viral loads, and widespread fetal infection. Interestingly, early protection was observed even in the absence of strong humoral responses in some vaccinated sows, suggesting a potential role for innate or T-cell-mediated immunity in conferring rapid protection. Conclusions: The demonstrated efficacy of FlagT4G within two weeks of vaccination underscores its feasibility for integration into emergency vaccination programs. Its DIVA compatibility and ability to induce early fetal protection against highly virulent CSFV strains position it as a promising tool for CSF control and eradication strategies.This research was funded by USDA-IRTA Agreement No. NACA 58-8064-0-013F and the Spanish Ministry of Science and Innovation, grant PID2021-125599OB-100. L.C. was supported by the Juan de la Cierva Program (2022), Spanish Ministry of Science and Innovation. A.M.-A. was supported by the ICA grant 001-2022. The IRTA is supported by the CERCA program/Generalitat de Catalunya.info:eu-repo/semantics/publishedVersio
Bycatch in Cetaceans from the North-Western Mediterranean Sea: Retrospective Study of Lesions and Utility of Bycatch Criteria
Get PDFBycatch (accidental capture in fisheries) is the most common cause of death of small delphinids worldwide. Determining bycatch to be the primary cause of death in a free-ranging stranded cetacean relies on the detection of lesions termed “bycatch criteria”, that vary in their specificity. Here, we retrospectively reviewed the bycatch criteria found in 138 necropsied cetaceans from the North-western Mediterranean Sea in a 13-year period to identify the most reliable criteria. Bycatch was determined as the cause of death/stranding in 40 (29%) of cetaceans. Both sexes were equally represented in the bycatch group. Bycatch was diagnosed in the Mediterranean common bottlenose dolphin (10/14; 71.4%), striped dolphin (29/108; 26.9%), and Risso’s dolphin (1/11; 9.1%). Recent feeding, absence of disease, good nutritional status, marks of fishing gear, intravascular gas bubbles, hyphema and amputations or sharp incisions presumably inflicted by humans were significantly more likely to result in a diagnosis of bycatch, while loss of teeth and cranial fractures were not. None of the dolphins diagnosed as bycatch had ingested fishing gear. Our results highlight the relevance of bycatch as cause of death of dolphins in the Mediterranean and show that some criteria traditionally linked to bycatch are not specific for bycatch in our region.Necropsies were performed with official governmental permits and were funded by Direcció de Medi Natural i Biodiversitat (Generalitat de Catalunya), including projects AG-2015-474, PTOP-2016-663, and PTOP-2021-14 (GJ513324). Additional financial support came from Servei de Diagnòstic de Patologia Veterinària (Universitat Autònoma de Barcelona).info:eu-repo/semantics/publishedVersio
Identification of Gambierdiscus species from La Réunion and evaluation of toxicity and toxin profile
Get PDFFive different species of Gambierdiscus have been identified in La Réunion (G. belizeanus, G. balechii, G. pacificus, G. silvae and G. ribotype 2) by morphological observations in Scanning Electron Microscopy (SEM) and molecular identification and phylogenetic analysis. Growth rates of cultures have also been evaluated showing values from 0.09 to 0.36 d-1.
The toxicity and toxin profile of thirteen strains have been analysed by a multidisciplinary approach with Neuro-2a cell-based assay (CBA), magnetic bead-based immunoassay, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and LC coupled to high-resolution mass spectrometry (LCsingle bondHRMS). G. balechii showed the highest toxicity by CBA (∼627 fg equiv. CTX1B·cell -1) followed by G. ribotype 2 (76 to 13 fg equiv. CTX1B·cell -1), G. balechii (63 to 7 fg equiv. CTX1B·cell -1), G. belizeanus (30 to 20 fg equiv. CTX1B·cell -1) and G. pacificus with values close to LOQ but not conclusive. The toxin profile for the 13 strains was evaluated by LC-MS/MS using seven different methods and being gambierone and 44-methylgambierone the two only known compounds, found in high concentrations in all samples. Gambierone was detected from 2.05 pg ·cell-1 in G. balechii (P-0414B) to 12.91 pg·cell-1 in G. balechii (P-0414A) and 44-methylgambierone was detected from 1.93 pg·cell-1 in G. belizeanus (P-0414B) to 14.95 pg·cell-1 in G. pacificus (P-0304). These samples were analysed also by LCsingle bondHRMS, confirming gambierone and 44-methylgambierone the main compounds detected. Additionally, a potential polyether sulphur-containing compound corresponding to the novel molecular formula C62H94O23S ([M+NH4]+, m/z 1256.6234) were tentatively identified.
This study combining morphological and molecular data is the first to mention such diversity in the area. It is also the first time that toxicity and toxin profile of Gambierdiscus from La Réunion have been evaluated.info:eu-repo/semantics/publishedVersio
Integrated brain and testis transcriptomic analyses reveal the benefits of sandy environmental enrichment in Senegalese sole male (Solea senegalensis) reproduction
Get PDFThis study investigates the effects of physical enrichment (sand substrate) on the gonadal development and transcriptomics of juvenile Senegalese sole (Solea senegalensis). A total of 1500 fish were distributed into six outdoor fiberglass tanks, three of which included a 2 cm layer of sand to simulate physical enrichment. Throughout a two-year study, the fish were sampled at four intervals, corresponding to developmental stages ranging from juvenile, pre-pubertal to adult. Blood, testis, and brain tissues were collected at each sampling point to analyse hormonal profiles (estradiol, testosterone, follicle-stimulating and luteinizing hormones) and gene expression. Histological analysis of testicular tissue was used to assess the germ cell development stages, while RNA sequencing (RNA-seq) was performed to evaluate the impact of physical enrichment on transcriptomic profiles in both the brain and testes. Sandy environmental enrichment is associated with increased testosterone and luteinizing hormone levels. Bioinformatics analysis identified differentially expressed genes (DETs) associated with reproduction, immune response, and metabolism. GO and KEGG enrichment analysis demonstrated that important terms and pathways associated with the process of spermatogenesis, cognition and metabolism where differentially enriched between males maintained in sand and fiberglass. These results provided new insights into how environmental enrichment influences reproductive physiology and molecular mechanisms in cultured Senegalese sole from very early stages.info:eu-repo/semantics/publishedVersio