@article {6916, title = {An integrated investigation of the effects of ocean acidification on adult abalone (Haliotis tuberculata)}, journal = {ICES Journal of Marine Science}, volume = {77}, year = {2020}, month = {Sep-01-2020}, pages = {757 - 772}, type = {research article}, abstract = {Ocean acidification (OA) and its subsequent changes in seawater carbonate chemistry are threatening the survival of calcifying organisms.Due to their use of calcium carbonate to build their shells, marine molluscs are particularly vulnerable. This study investigated the effect of CO2-induced OA on adult European abalone (Haliotis tuberculata) using a multi-parameter approach. Biological (survival, growth), physiological (pHT of haemolymph, phagocytosis, metabolism, gene expression), and structural responses (shell strength, nano-indentation measurements,Scanning electron microscopy imaging of microstructure) were evaluated throughout a 5-month exposure to ambient (8.0) and low (7.7) pH conditions. During the first 2 months, the haemolymph pH was reduced, indicating that abalone do not compensate for the pH decrease of their internal fluid. Overall metabolism and immune status were not affected, suggesting that abalone maintain their vital functions when facing OA. However, after 4 months of exposure, adverse effects on shell growth, calcification, microstructure, and resistance were highlighted, whereas the haemolymph pH was compensated. Significant reduction in shell mechanical properties was revealed at pH 7.7, suggesting that OA altered the biomineral architecture leading to a more fragile shell. It is concluded that under lower pH, abalone metabolism is maintained at a cost to growth and shell integrity. This may impact both abalone ecology and aquaculture.}, keywords = {Abalone, calcification, Gene Expression, Growth, mechanical properties, Ocean acidification, Physiology, shell microstructure}, issn = {1054-3139}, doi = {10.1093/icesjms/fsz257}, url = {https://academic.oup.com/icesjms/article/77/2/757/5699268}, author = {Avignon, Sol{\`e}ne and St{\'e}phanie Auzoux-Bordenave and Martin, Sophie and Dubois, Philippe and Badou, Aicha and Coheleach, Manon and Richard, Nicolas and Di Giglio, Sarah and Malet, Lo{\"\i}c and Servili, Arianna and Gaillard, Fanny and Huchette, Sylvain and Roussel, Sabine} } @article {6915, title = {Ocean acidification impacts growth and shell mineralization in juvenile abalone (Haliotis tuberculata)}, journal = {Marine Biology}, volume = {167}, year = {2020}, month = {Jan-01-2020}, type = {research article}, abstract = {Ocean acidification is a major global driver that leads to substantial changes in seawater carbonate chemistry, with potentially serious consequences for calcifying organisms. Marine shelled molluscs are ecologically and economically important species, providing essential ecosystem services and food sources for other species. Due to their physiological characteristics and their use of calcium carbonate (CaCO3) to build their shells, molluscs are among the most vulnerable invertebrates with regard to ocean acidification, with early developmental stages being particularly sensitive to pH changes. This study investigated the effects of CO2-induced ocean acidification on juveniles of the European abalone Haliotis tuberculata, a commercially important gastropod species. Six-month-old juvenile abalones were cultured for 3 months at four pH levels (8.1, 7.8, 7.7, 7.6) representing current and predicted near-future conditions. Survival, growth, shell microstructure, thickness and strength were compared across the four pH treatments. After three months of exposure, significant reductions in juvenile shell length, weight and strength were revealed in the pH 7.6 treatment. SEM observations also revealed modified texture and porosity of the shell mineral layers as well as alterations of the periostracum at pH 7.6 which was the only treatment with an aragonite saturation state below 1. It is concluded that low pH induces both general effects on growth mechanisms and corrosion of deposited shell in H. tuberculata.
This will impact both the ecological role of this species and the costs of its aquaculture.}, keywords = {Abalone, Growth, Juvenile, Ocean acidification, Shell mineralization}, issn = {0025-3162}, doi = {10.1007/s00227-019-3623-0}, url = {http://link.springer.com/10.1007/s00227-019-3623-0}, author = {St{\'e}phanie Auzoux-Bordenave and Wessel, Nathalie and Badou, Aicha and Martin, Sophie and M{\textquoteright}Zoudi, Saloua and Avignon, Sol{\`e}ne and Roussel, Sabine and Huchette, Sylvain and Dubois, Philippe} } @article {5619, title = {Effect of CO2{\textendash}induced ocean acidification on the early development and shell mineralization of the European abalone (Haliotis tuberculata)}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {508}, year = {2018}, pages = {52 - 63}, abstract = {

Ocean acidification is a major global stressor that leads to substantial changes in seawater carbonate chemistry, with potentially significant consequences for calcifying organisms. Marine shelled mollusks are ecologically and economically important species providing essential ecosystem services and food sources for other species. Because they use calcium carbonate (CaCO3) to produce their shells, mollusks are among the most vulnerable invertebrates to ocean acidification, with early developmental stages being particularly sensitive to pH changes. This study investigated the effects of CO2-induced ocean acidification on larval development of the European abalone Haliotis tuberculata, a commercially important gastropod species. Abalone larvae were exposed to a range of reduced pHs (8.0, 7.7 and 7.6) over the course of their development cycle, from early-hatched trochophore to pre-metamorphic veliger. Biological responses were evaluated by measuring the survival rate, morphology and development, growth rate and shell calcification. Larval survival was significantly lower in acidified conditions than in control conditions. Similarly, larval size was consistently smaller under low pH conditions. Larval development was also affected, with evidence of a developmental delay and an increase in the proportion of malformed or unshelled larvae. In shelled larvae, the intensity of birefringence decreased under low pH conditions, suggesting a reduction in shell mineralization. Since these biological effects were observed for pH values expected by 2100, ocean acidification may have potentially negative consequences for larval recruitment and persistence of abalone populations in the near future.

}, keywords = {Abalone, larval development, Ocean acidification, Shell mineralization}, issn = {0022-0981}, doi = {https://doi.org/10.1016/j.jembe.2018.08.005}, url = {http://www.sciencedirect.com/science/article/pii/S0022098117304070}, author = {Nathalie Wessel and Sophie Martin and Badou, Aicha and Philippe Dubois and Sylvain Huchette and Vivien Julia and Flavia Nunes and Ewan Harney and Christine Paillard and St{\'e}phanie Auzoux-Bordenave} } @article {4554, title = {Shell growth, microstructure and composition over the development cycle of the European abalone Haliotis tuberculata}, journal = {Marine Biology}, volume = {162}, year = {2015}, pages = {687{\textendash}697}, abstract = {

The shell of the European abalone Haliotis tuberculata is a model for studying mechanisms of mollusc shell formation, but the early steps of shell formation and calcification remain poorly documented. The microstructure and the mineralogical and geochemical composition of larval and juvenile shells were investigated by scanning electron microscopy, infrared spectroscopy and ion microprobe analyses (NanoSIMS). Analyses were performed on shells obtained from controlled fertilisations at the hatchery France-Haliotis (Plouguerneau, France) in July 2009 and 2010 using abalone from Roscoff. Shell cross sections revealed the microstructural arrangement of the developing shell, showing progressive biomineral organisation into two differentiated layers, i.e. the outer granular and the internal nacreous layer. Infrared analysis confirmed that the European abalone shell, at every stage of development, was mostly composed of CaCO3 in the form of aragonite. Variations in trace element composition, i.e. Sr/Ca, were measured in the different stages and correlated with micro-structural changes in the shells. Experimental manganese labelling of live abalones produced cathodoluminescence marks in the growing shell sections. The increase in shell thickness can be used to determine the growth rate of an early adult abalone shell.

}, issn = {1432-1793}, doi = {10.1007/s00227-015-2615-y}, url = {http://dx.doi.org/10.1007/s00227-015-2615-y}, author = {St{\'e}phanie Auzoux-Bordenave and Brahmi, C. and Badou, Aicha and de Raf{\'e}lis, M. and Huchette, S.} } @article {3490, title = {Characterisation and expression of the biomineralising gene Lustrin A during shell formation of the European abalone Haliotis tuberculata}, journal = {Comparative Biochemistry and Physiology , Part B}, volume = {169}, year = {2014}, month = {2014}, pages = {1-8}, type = {Research article}, abstract = {

The molluscan shell is a remarkable product of a highly biomineralisation process, and is composed of calcium carbonate most commonly in the form of calcite or aragonite. The exceptional mechanical properties of this biomaterial are imparted by the embedded organic matrix which is secreted by the underlying mantle tissue. While many shell-matrix proteins have already been identified within adult molluscan shell, their presence and role in the early developmental stages of larval shell formation are not well understood. In the European abalone Haliotis tuberculata, the shell first forms in the early trochophore larva and develops into a mineralised protoconch in the veliger. Following metamorphosis, the juvenile shell rapidly changes as it becomes flattened and develops a more complex crystallographic profile including an external granular layer and an internal nacreous layer. Among the matrix proteins involved in abalone shell formation, Lustrin A is thought to participate in the formation of the nacreous layer. Here we have identified a partial cDNA coding for the Lustrin A gene in H. tuberculata and have analysed its spatial and temporal expression during abalone development. RT-PCR experiments indicate that Lustrin A is first expressed in juvenile (post-metamorphosis) stages, suggesting that Lustrin A is a component of the juvenile shell, but not of the larval shell. We also detected Lustrin A mRNAs in non-nacre forming cells at the distal-most edge of the juvenile mantle as well as in the nacre-forming region of the mantle. Lustrin A was also expressed in 7-day-old post-larvae, prior to the formation of nacre. These results suggest that Lustrin A plays multiple roles in the shell-forming process and further highlight the dynamic ontogenic nature of molluscan shell formation.

}, keywords = {biomineralisation, Haliotis tuberculata, larval development, Lustrin A, mollusc, organic matrix, shell}, author = {Gaume, B{\'e}atrice and Denis, Fran{\c c}oise and Van Wormhoudt, Alain and Huchette, Sylvain and Jackson, Daniel and Avignon, Sol{\`e}ne and St{\'e}phanie Auzoux-Bordenave} }