@article {9138, title = {How ocean warming and acidification affect the life cycle of six worldwide commercialised sea urchin species: A review}, journal = {Aquaculture, Fish and Fisheries}, year = {2023}, month = {Jul-04-2023}, abstract = {Ongoing global changes are expected to affect the worldwide production of many fisheries and aquaculture systems. Because invertebrates represent a relevant industry, it is crucial to anticipate challenges that are resulting from the current environmental alterations. In this review, we rely on the estimated physiological limits of six commercialised species of sea urchins (Loxechinus albus, Mesocentrotus franciscanus, Paracentrotus lividus, Strongylocentrotus droebachiensis, Strongylocentrotus\  intermedius and Strongylocentrotus purpuratus) to define the vulnerability (or resilience) of their populations facing ocean warming and acidification (OW\&A). Considering that coastal systems do not change uniformly and that the populations{\textquoteright} response to stressors varies depending on their origin, we investigate the effects of OW\&A by including studies that estimate future environmental mutations within their distribution areas. Crossreferencing 79 studies, we find that several sea urchin populations are potentially vulnerable to the predicted OW\&A as environmental conditions in certain regions are expected to shift beyond their estimated physiological limit of tolerance. Specifically, while upper thermal thresholds seem to be respected for L. albus along the SW American coast, M. franciscanus and S. purpuratus southern populations appear to be vulnerable in NW America. Moreover, as a result of the strong warming expected in the Arctic and sub-Arctic regions, the local productivity of S. droebachiensis is also potentially largely affected. Finally, populations of S. intermedius and P. lividus found in northern Japan and eastern Mediterranean respectively, are supposed to decline due to large environmental changes brought about by OW\&A. This review highlights the status and the potential of local adaptation of a number of sea urchin populations in response to changing environmental conditions, revealing possible future challenges for various local fishing industries.}, keywords = {Aquaculture, ecophysiology, fishery, Ocean acidification, ocean warming, sea urchin}, issn = {2693-8847}, doi = {10.1002/aff2.107}, url = {https://onlinelibrary.wiley.com/doi/10.1002/aff2.107}, author = {Uboldi, Thomas and Fr{\'e}d{\'e}ric Olivier and Chauvaud, Laurent and Tremblay, Rejean} } @article {5315, title = {Cultured eastern oysters (Crassostrea virginica): retention and assimilation of picophytoplankton using a multi-biomarker approach}, journal = {Aquatic Living Resources}, volume = {30}, year = {2018}, month = {08/2018}, type = {Article}, abstract = {

{In this study, we investigated the food sources of eastern oysters Crassostrea virginica cultivated in Atlantic Canada. Stable isotopes (C-13 and N-15) and fatty acid biomarkers were used to identify these sources under in situ conditions for suspended (similar to 0.5 m below surface) and bottom(similar to 2 m) culture stocks. It was found that particulate organic matter represented the main food source, with major contributions from live phytoplankton. Higher lipid contents were detected in the digestive glands of suspended oysters compared to bottom oysters (p \< 0.05). Bottom oysters did not show significant preference for detrital or bacterial organic matter. Near-surface waters contained an elevated picophytoplankton biomass (PPP, 0.2-2 mu m, 1.93 +/- 0.16mg l(-1), mean +/- SEM) compared to nanophytoplankton biomass (NPP, \> 2 mu m, 1.05 +/- 0.15 mu g l(-1), mean +/- SEM). To determine whether the small size PPP was captured and assimilated by C. virginica, feeding trials were conducted in the laboratory using three PPP/NPP diets (20\%, 50\%, and 80\% PPP), consisting of isotopically-labelled (delta C-13) PPP cells (Nannochloropsis oculata) and non-labelled NPP cells (Tisochrysis lutea). An isotopically-labelled fatty acids analysis indicated PPP assimilation in various tissues (digestive gland, gills, mantle, and abductor muscle), including from oysters fed the reduced (20\%) PPP diet. Isotopic enrichment (C-13) in the FA 22:2 (non-methylene-interrupted or NMI) showed that precursors of NMIs utilized PPP carbon in its biosynthesis process. In conclusion, C. virginica assimilated primarily particulate organic matter (POM), including PPP, which dominated the phytoplankton community in near surface waters. C. virginica can exploit PPP carbon during fatty acid production and further biosynthesis.}

}, keywords = {Aquaculture, fatty acids, Picophytoplankton, Shellfish}, Stable isotopes, {Crassostrea virginica}, issn = {{0990-7440}}, doi = {{10.1051/alr/2017031}}, author = {R{\'e}mi Sonier and R{\'e}jean Tremblay and Fr{\'e}d{\'e}ric Olivier and Tarik Meziane and Comeau, Luc Andre} } @article {5499, title = {Dietary aquaculture by-product hydrolysates: impact on the transcriptomic response of the intestinal mucosa of European seabass (Dicentrarchus labrax) fed low fish meal diets}, journal = {BMC Genomics}, volume = {19}, year = {2018}, abstract = {

Aquaculture production is expected to double by 2030, and demands for aquafeeds and raw materials are expected to increase accordingly. Sustainable growth of aquaculture will require the development of highly nutritive and functional raw materials to efficiently replace fish meal. Enzymatic hydrolysis of marine and aquaculture raw materials could bring new functionalities to finished products. The aim of this study was to determine the zootechnical and transcriptomic performances of protein hydrolysates of different origins (tilapia, shrimp, and a combination of the two) in European seabass (Dicentrarchux labrax) fed a low fish meal diet (5\%), for 65\ days.

Results

Results were compared to a positive control fed with 20\% of fish meal. Growth performances, anterior intestine histological organization and transcriptomic responses were monitored and analyzed. Dietary inclusion of protein hydrolysates in the low fish meal diet restored similar growth performances to those of the positive control. Inclusion of dietary shrimp hydrolysate resulted in larger villi and more goblet cells, even better than the positive control. Transcriptomic analysis of the anterior intestine showed that dietary hydrolysate inclusion restored a pattern of intestinal gene expression very close to the pattern of the positive control. However, as compared to the low fish meal diet and depending on their origin, the different hydrolysates did not modulate metabolic pathways in the same way. Dietary shrimp hydrolysate inclusion modulated more metabolic pathways related to immunity, while nutritional metabolism was more impacted by dietary tilapia hydrolysate. Interestingly, the combination of the two hydrolysates enhanced the benefits of hydrolysate inclusion in diets: more genes and metabolic pathways were regulated by the combined hydrolysates than by each hydrolysate tested independently.

Conclusions

Protein hydrolysates manufactured from aquaculture by-products are promising candidates to help replace fish meal in aquaculture feeds without disrupting animal metabolism and performances.

}, keywords = {Aquaculture, Aquafeed, By-products, European seabass, Fishmeal replacement, Hydrolysate, Illumina RNA-sequencing, Intestinal organization, Metabolic pathways}, doi = {doi.org/10.1186/s12864-018-4780-0}, author = {Leduc, Alexandre and C{\'e}line Zatylny-Gaudin and Robert, Marie and Corre, Erwan and Le Corguill{\'e}, Gildas and Castel, H{\'e}l{\`e}ne and Lefevre-Scelles, Antoine and Fournier, Vincent and Gisbert, Enric and Andree, Karl B. and Jo{\"e}l Henry} } @article {6665, title = {Digestive enzyme ratios are good indicators of hatchling yolk reserve and digestive gland maturation in early life stages of cuttlefish Sepia officinalis L.: application of these new tools in ecology and aquaculture}, journal = {Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology}, volume = {188}, year = {2018}, pages = {57-76}, abstract = {In Sepia officinalis (Linnaeus, 1758), the digestive gland matures during the first month post-hatching, while a shift from intracellular acid to extracellular alkaline digestion occurs. The purpose of this study was to investigate the possibility of using enzymatic ratios for the description of digestive system maturation in early life stages of S. officinalis. Second, it is intended to apply these new tools as eco-physiological indicators for understanding the impact of cuttlefish eggs{\textquoteright} life history from different spawning sites of the English Channel on digestive performance of juveniles. An experimental rearing was performed over 35\ days after hatching (DAH) on juveniles from wild collected eggs in 2010 and 2011. Four digestive enzyme activities and their ratios [i.e., trypsin, cathepsin, acid (ACP), and alkaline (ALP) phosphatase, ALP/ACP, and trypsin/cathepsin] were studied along with histological features (e.g., internal yolk surface and digestive gland development). The two enzyme ratios were good indicators of digestive system maturation allowing the study of the digestive gland{\textquoteright}s development. They were highly correlated to juveniles{\textquoteright} weight increase and histological features of the gland in early DAH. These ratios described more accurately the shift occurring between the intracellular acid and the extracellular alkaline modes of digestion in S. officinalis and were more specific than separated enzyme activities. Their application as eco-physiological tools revealed that enzyme ratios reflected yolk content and digestive gland development in new hatching juveniles. Finally, ALP/ACP ratio was shown to be a powerful tool to describe growth performance of S. officinalis which is useful for aquaculture optimization. {\textcopyright} 2017, Springer-Verlag GmbH Germany.}, keywords = {Acid Phosphatase, alkaline phosphatase, anatomy and histology, animal, Animals, Aquaculture, cathepsin, Cathepsins, cuttlefish, Gastrointestinal Tract, Physiology, Sepia, Trypsin}, issn = {01741578}, doi = {10.1007/s00360-017-1115-4}, url = {https://link.springer.com/article/10.1007\%2Fs00360-017-1115-4}, author = {Safi, Georges and Anne-Sophie Martinez and Le Pabic, Charles and Estelle Le Bihan and Jean-Paul Robin and Koueta, Noussith{\'e}} }