Sexual dimorphism in the shells of the southwestern Atlantic gastropod Olivella plata (Ihering, 1908) (Gastropoda: Olividae)

PASTORINO, G.

JOURNAL OF MOLLUSCAN STUDIES

Oxford University Press

Lugar: Oxford; Año: 2007 vol. 73 p. 283 - 285

0260-1230

Sexual dimorphism is clearly visible on female shells. These show an anterior wide vertical groove, adjacent to the parietal callus and the pillar structure. The groove is not on the same plane as the aperture, i.e., it runs approximately at right angles to the apertural plane. Therefore, it is clearly visible in lateral view and not quite so in apertural or adapertural views. The groove curves adaxially at the tip of the also curved pillar. It grows at the same rhythm as the shell judging by the growth lines visible at the bottom of it (Figs. 4, 7, 9,10). Male shells are easily distinguished because there is no groove but a continuation of the parietal callus which, apparently “infills” the groove described for the female shells