Langer G. auteur aut IRD Nehrke G. auteur aut IRD Baggini C. auteur aut IRD Rodolfo-Metalpa Riccardo auteur aut IRD Hall-Spencer J. M. auteur aut IRD Bijma J. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Specimens of the patellogastropod limpet Patella caerulea were collected within (pH(low)-shells) and outside (pHn-shells) a CO2 vent site at Ischia, Italy. Four pH(low)-shells and four pHn-shells were sectioned transversally and scanned for polymorph distribution by means of confocal Raman microscopy. The pHlow-shells displayed a twofold increase in aragonite area fraction and size-normalised aragonite area. Size-normalised calcite area was halved in pH(low)-shells. Taken together with the increased apical and the decreased flank size-normalised thickness of the pH(low)-shells, these data led us to conclude that low-pH-exposed P. caerulea specimens counteract shell dissolution by enhanced shell production. This is different from normal elongation growth and proceeds through addition of aragonitic parts only, while the production of calcitic parts is confined to elongation growth. Therefore, aragonite cannot be regarded as a disadvantageous polymorph per se under ocean acidification conditions. specialized ITALIE MEDITERRANEE TYRRHENIENNE MER 036 032 11 24 7363-7368 2014 1726-4170 https://www.documentation.ird.fr/hor/fdi:010063700 10.5194/bg-11-7363-2014 1726-4170 [F B010063700] https://www.documentation.ird.fr/hor/fdi:010063700 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-10/010063700.pdf IRD - Base Horizon / Pleins textes 2015-03-03 2017-10-31 fdi:010063700 fre