Polychaete (Alitta virens) meal inclusion as a dietary strategy for modulating gut microbiota of European seabass (Dicentrarchus labrax).

Recent research has revealed the significant impact of novel feed ingredients on fish gut microbiota, affecting both the immune status and digestive performance. As a result, analyzing the microbiota modulatory capabilities may be a useful method for assessing the potential functionality of novel ingredients. Therefore, this study aimed to evaluate the effects of dietary polychaete meal (PM) from Alitta virens on the autochthonous and allochthonous gut microbiota of European seabass (Dicentrarchus labrax). Two diets were compared: a control diet with 25% fishmeal (FM) and a diet replacing 40% of fishmeal with PM, in a 13- week feeding trial with juvenile fish (initial weight of 14.5 ± 1.0 g). The feed, digesta, and mucosa-associated microbial communities in fish intestines were analyzed using high-throughput sequencing of the 16S rRNA gene on the Illumina MiSeq platform. The results of feed microbiota analyses showed that the PM10 feed exhibited a higher microbial diversity than the FM diet. However, these feed-associated microbiota differences were not mirrored in the composition of digesta and mucosal communities. Regardless of the diet, the digesta samples consistently exhibited higher species richness and diversity than the mucosa samples. Overall, digesta samples were characterized by a higher abundance of Firmicutes in PM-fed fish. In contrast, at the gut mucosa level, the relative abundances of Mycobacterium, Taeseokella and Clostridium genera were lower in the group fed the PM10 diet. Significant differences in metabolic pathways were also observed between the FM and PM10 groups in both mucosa and digesta samples. In particular, the mucosal pathways of caffeine metabolism, phenylalanine metabolism, and sulfur relay system were significantly altered by PM inclusion. The same trend was observed in the digesta valine, leucine, and isoleucine degradation and secretion pathways. These findings highlight the potential of PM as an alternative functional ingredient in aquafeeds with microbiota modulatory properties that should be further explored in the future

Welfare and performance of ballan wrasse (Labrus bergylta) reared at two different temperatures after a preparatory feeding trial with enhanced dietary eicosapentaenoic acid

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Effects of novel ingredients on growth performance in european sea bass, dicentrarchus labrax

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A data driven approach to landslide susceptibility mapping in Great Britain

Landslides are a geo-hazard which can have significant societal impacts including loss of human life, physical damage to infrastructure and financial loss. The ability to assess where landslides will occur is therefore of great interest for the public good and can be approached both theoretically and empirically. With the ever increasing availability of spatial data, information on landslide events is now much more readily available ranging from initiation point coordinates to high (sub-metre) resolution topographic information and associated derivatives on affected (and unaffected) areas. Coupled with information on the geology of a region, it is possible to build up a detailed location specific profile of past events, all of which may prove useful for informing where future events may occur. We present preliminary results from an assessment of various data to reassess current British landslide susceptibility datasets. These could be used in future to provide additional information to support landslide forecasting. We define susceptibility as: The potential for the occurrence of a hazard within a specified area. This is currently provided for by the BGS GeoSure Landslides product [1] which classifies landslide prone areas on an A-E (low-high) basis, based on heuristics as well as consideration of lithology, discontinuities and slope angle. Data-driven analyses may provide further insights into where and why landslides occur. Using this knowledge, we hope to improve our current landslide susceptibility model. Consequently, this will enable us to be more confident in the identification of areas where landslides may occur in the future

Efficacy of 2-phenoxyethanol as an anaesthetic for two size classes of white sea bream, Diplodus sargus L., and sharp snout sea bream, Diplodus puntazzo C

The objective of this study was to evaluate the efficacy of 2-phenoxyethanol as an anaesthetic for two size classes of white sea bream, Diplodus sargus L. (30 and 60 g), and sharp snout sea bream, Diplodus puntazzo C., (15 and 30 g) and establish the minimum concentration producing desirable anaesthetic effects on them. Fish were exposed to concentrations varying from 0.1 to 0.4 mL/L for a 60-min period. At concentrations of 0.1, 0.117 and 0.133 mL/L, 2-phenoxyethanol failed to induce anaesthesia, whereas at concentrations of 0.167, 0.2, 0.3 and 0.4 mL/L all the fish were anaesthetised within 3 min of exposure. However, mortality was observed with the two higher concentrations. Induction time decreased and recovery time increased with increasing concentrations, being significantly concentration-dependent in both species (P ≤ 0.01). Following exposure of D. sargus to concentrations of 0.2 or 0.3 mL/L, both induction and recovery time were significantly weight-dependent (P ≤ 0.01). However, erratic weight dependencies of both induction and recovery time were observed in D. puntazzo. 2-Phenoxyethanol proved to be an effective and safe anaesthetic in both species permitting rapid and uneventful induction and recovery after a 60-min exposure period. The minimum concentration producing desirable anaesthetic effects was 0.167 mL/L. © 2005 Elsevier B.V. All rights reserved

Dietary lysine imbalance affects muscle proteome in zebrafish (Danio rerio): a comparative 2D-DIGE study

Lysine (Lys) is an indispensable amino acid (AA) and generally the first limiting AA in vegetable protein sources in fish feeds. Inadequate dietary Lys availability may limit protein synthesis, accretion and growth of fish. This experiment aimed to further elucidate the role of Lys imbalance on growth by examining the myotomal muscle proteome of juvenile zebrafish (Danio rerio). Quadruplicate groups of 8 fish were fed either a low-Lys [Lys(−), 1.34 gkg−1], medium/control (Lys, 2.47 gkg−1) or high-Lys [Lys(+), 4.63 gkg−1] diet. Fish growth was monitored from 33 to 49 days postfertilization (dpf) and trunk myotomal muscle proteome of Lys(−) and Lys(+) treatments were screened by 2D-DIGE and MALDI ToF tandem mass spectrometry. Growth rate was negatively affected by diet Lys(−). Out of 527±11 (mean±S.E.M.) protein spots detected (∼10–150 kDa and 4–7 pI value), 30 were over-expressed and 22 under-expressed in Lys(−) fish (|fold-change|>1.2, p value <0.05). Higher myosin light chains abundance and other myofibrillar proteins in Lys (−) fish pointed to increased sarcomeric degradation, indicating a higher protein turnover for supplying basal energysaving metabolism rather than growth and muscle protein accretion. The Lys deficiency also possibly induced a higher feeding activity, reflected in the over-expression of beta enolase and mitochondrial ATP synthase. Contrarily, in the faster growing fish [Lys(+)], over-expression of apolipoprotein A-I, F-actin capping protein and Pdlim7 point to increased energy storage as fat and enhanced muscle growth, particularly by mosaic hyperplasia. Thus using an exploratory approach, this study pinpoints interesting candidates for further elucidating the role of dietary Lys on growth of juvenile fish

Environment and feeding for optimal health and survival of cleaner fish in sea cages

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