| This paper presents a simple method of individual age determination of the gastropod Buccinum undatum, based on the counting of operculum striae. The validation of this method is achieved by the use of several unrelated approaches. As a first step, oxygen stable isotopie analysis is used to check shell records of seasonal temperature fluctuations. We then establish a geometrie correspondence between simultaneously elaborated parts of the shell and the operculum, and show that the mean periodicity of operculum striae formation is annual. With the help of complementary data collected on the fishing grounds, and also of a biometrical study, it is further shown that the age criterion is marked during the warmer months of the year, between June and October.... |
