Hexagon Tusk Shell, Dentalium neohexagonum

Hexagon Tusk Shell, Dentalium neohexagonum. Shell collected off the beach of Bahía Concepción, Baja California Sur, October 2019. Size: 2.5 cm (1.0 inch). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Hexagon Tusk Shell, Dentalium neohexagonum (Pilsbry and Sharp, 1892), is a marine scaphopod mollusk that is a member of the Dentalidae Family of Tusk Shells, and a representative of the Scaphopods Class. The genus Dentalium is one of thirteen genera in this family, and there are seventy species in this genus.  This species is also known as the six-sided tusk shell. In Mexico they are called Dentalium Hexagonal.

Description: The Hexagon Tusk Shell is tusk-shaped, and has six strong ribs, running the length of the shell that affords the shell a hexagonal cross-section. These angles are more pronounced at the wide end of the shell. The shells are white in color. Hexagon Tusk Shells reach 3.3 cm (1.3 inches) in length.

Habitat and Distribution:  Hexagon Tusk Shells are found on and within sand and mud substrates. They live at depths between 7 m (15 feet) and 256 m (840 feet). They are a temperate to subtropical Eastern Pacific species.  In Mexican waters they are found along the entire west coast of the Baja Peninsula and they are found in the Gulf of California from Isla Tiburon, Baja California to Cabo San Lucas, Baja California Sur.

Ecology and Behavior: Hexagon Tusk Shells feed on foraminifera, mollusk larvae, and detritus, which they sift from the sand. Their predators include rays and ratfish. They are gonochoric and reproduce sexually, with internal fertilization. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.

Synonyms: None