Variability in the crystallographic texture of bivalve nacre

Bulletin of geosciences

Klicnarová K¹  Frýda J¹  Frýdová B¹  Mergl M¹ 

关键词: Bivalvia;    nacre;    crystallographic texture;    phylogeny;   

DOI  :  

来源: Czech Geological Survey

【 摘 要 】

ThecrystallographictextureofnacreinelevenbivalvespeciesbelongingtothesuperordersOpponobranchia,Pteriomorpha,andPaleoheterodonta,wasstudied.Ouranalysisconfirmedauniformorientationofthecrystallographicc-axesofaragoniteplateletsinallthespeciesstudied,butavariablearrangementofa-andb-axes.Newdatasuggestthattherateofalignmentofa-andb-axesfromgirdle-like(unorderednacre)toasinglecrystal-liketexture(orderednacre)differsconsiderablyamongtheanalyzedspecies.Numericalevaluationofthedataobtainedfromspecieswithorderednacrealsorevealedsystematicdifferencesintexturestrengthamongthemaincrystallographicaxesofaragoniteplatelets.Thetexturestrengthofa-axes(directionparalleltogrowthlines)isalwaysweakerthanthatofb-andc-axes.Observeddifferencesinshapeofthegrowthlinesonthesurfaceofnacreousplatelets,intwinningpercentageaswellasinrateofalignmentofa-andb-axessuggestvariationsinnacregrowthprocessinindividualphylogeneticlineagesoftheClassBivalvia.Thesefactsmayimplynotonlyevolutionarychangesinmicrostructureandcrystallographictextureofthenacrebutalsoinmolecularmechanismsdrivingitsproductionduringthelongmolluscanevolution.

【 授权许可】

Unknown