Continuous growth-line sequences in gastropod shells

Studies of gastropod shell growth at the level of fine growth layers are scarce, because coiling of gastropod shells hinders the observation of continuous growth series spanning across whorls. We propose here a new method to obtain continuous growth patterns of gastropod shells over whorls with Terebralia palustris (L.) as an example. Comparison of vertical and horizontal sections of the shell of this species reveals that growth patterns can be observed continuously for several whorls on the vertical section of the columella. In addition, an obvious tidal growth pattern preserved in this species enables us to trace its growth with a precision of 12.4 h and indicates that it takes about two years for a shell to grow from 3 cm to 9.5 cm in height and add 5 complete whorls.