Lumpy Morum Shell, Morum tuberculosum

Lumpy Morum Shell, Morum tuberculosum. Shell collected off the beach in the greater Los Cabos area, Baja California Sur, March 2009. Size: 2.6 cm (1.1 inches) x 1.8 cm (0.7 inches).

The Lumpy Morum, Morum tuberculosum (Reeve, 1842), is a gastropod mollusk that is a  member of the Harpidae Family of Harps. They are also known as the Humped Morum Harp and in Mexico as morum jorobado. The shell is cylindrical in shape with exterior having sculpting with concentric rows of tubercles. Their spire is low to flat and the aperture is long and narrow. The exterior of the shells are generally cream colored, with dark brown blotches and speckles; the interiors are white to light yellow. The Lumpy Morum shells reach a maximum of 4.3 cm (1.7 inches) in length and 3.0 cm (1.2 inches) in height.

Lumpy Morums are found in sand, or under rocks in sand in the intertidal zone to depths up to 15 m (50 feet). They are found from Magdalena Bay, Baja California Sur along the southern west coast of the Baja, throughout the Sea of Cortez, and south to Peru.

Synonyms are Morum xanthostoma and Oniscia tuberculosa.