Torsion in Gastropoda
One of the most significant modifications of the molluscan body form in the gastropods occurs early in gastropod development. Torsion is a 180°, counterclockwise twisting of the visceral mass, mantle, and mantle cavity. Torsion positions the gills, anus, and openings from the excretory and reproductive systems just behind the head and nerve cords, and twists [...]
