Relationship between imposex and morphological variation of the shell in Nucella lapillus (Gastropoda : thaididae)

The relationship between imposer and shell morphology of the common dogwhel k, Nucella lapillus, was examined in populations from North Wales. Degree o f imposer, morphometry of the shell, habitat-exposure to wave action and su bstratum type were subjected to multivariate statistical analyses. Shell si ze increased significantly with increasing degree of imposer. This trend po ssibly is caused by a diversion of energy allocation from reproduction to s hell growth when reproductive effort is blocked or disturbed by imposer. (C ) 2000 Academic Press.