Solander’s Trivia Shell, Pusula solandri

Solander’s Trivia Shell, Pusula solandri. Shell collected off the beach of Bahía Concepción, Baja California Sur, October 2019. Size: 1.6 cm (0.6 inches) x 1.2 cm (0.5 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Solander’s Trivia, Pusula solandri (Gray, 1832), is a gastropod mollusk that is a member of the Triviidae Family of Trivias. They are also known as the False Cowry, the Sea Button and Solander’s Coffee-bean. The shells have an internal spire, the central ribs end in knobs at the furrow on the dorsal apex of the body whorl, and the aperture is fairly straight and toothed on both lips. They are a light brown or light gray in color and some have a pinkish tinge; the central ribs end in lighter colored knobs. Solander’s Trivia Shells reach a maximum of 2.2 cm (0.9 inches) in length and 1.6 cm (0.6 inches) in height.

Solander’s Trivial is very similar to the Coffee Bean Shell, Pusula pediculus (larger in stature with ribs that do not cross the midline).

Coffee Bean Shell, Pseudopusula californiana, on the right, versus Solander’s Trivia Shell, Trivia solandri. Photograph courtesy of Bob Hillis, Irvins, Utah.

Solander’s Trivias can also be easily confused with the Radiant Button Shell or Radiating Trivia Shell, Trivia radians (lighter in color and larger).

Solander’s Trivias reside attached to and under rocks in the intertidal zone to depths up to 35 m (115 feet). When actively feeding the mollusk its soft mantle sides emerge and join together at the mid-line of the back. The exposed mantle is soft gray with warty brown bumps. They are more commonly found as dead specimens washed up on the beach. They range from Southern California to Peru, including the Galapagos Islands and they are found throughout most of the Sea of Cortez.

Synonyms include Cypraea solandri, Pasula padreserrai, and Trivia solandri.