Delicate Hoof Shell, Hipponix delicatus
Delicate Hoof Shell, Hipponix delicatus. Shell collected off the beach of Todos Santos, Baja California Sur, May 2025. Size: 1.7 cm (0.7 inches) x 0.7 cm (0.3 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.
Delicate Hoof Shell, Hipponix delicatus. Shell collected off the beach of Punta Chivato, Baja California Sur, May 2025. Size: 2.0 cm (0.8 inches) x 0.8 cm (1.5 inches) x 0.8 cm (0.3 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.
Phylogeny: The Delicate Hoof Shell, Hipponix delicatus Dall, 1908, is a gastropod mollusk that is a member of the Hipponicidae Family of Hoof Shells. The genus Hipponix is one of eight genera in this family, and there are nineteen species in this genus. This species was first described by William Healey Dall who was Curator of the United States Collection of Mollusks at the Smithsonian Institution from 1869-1914. During that time he described 5,302 species of mollusks and 125 non-molluscan species.
Description: Delicate Hoof Shells are thick and obliquely conical shells that resemble limpets. They are irregularly circular in outline, though they are often shaped by the contours of the surface to which they are attached. Their apex if set near the posterior margin and curves slightly backward. They are sculpted with fine radial ribs, which are most visible at the margins, and fine lamellae. The interior horseshoe-shaped muscle scar opens toward the anterior. These shells are white. Delicate Hoof Shells reach a maximum of 2.0 cm (0.8 inches) in diameter. These shells closely resemble the Panamanian Hoof Shell, Antisabia panamensis, which has a flattened lip edge and coarser lamellae.
Habitat and Distribution: Delicate Hoof Shells are found on rocks, shells and other hard substrates in the intertidal zone, and to depths of, at least, 333 m (1,092 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception they that are absent from north of Todos Santos, Baja California Sur, along the central and northwest coasts of the Baja Peninsula and north of Punta Chivato, Baja California Sur, in the Sea of Cortez.
Ecology and Behavior: Delicate Hoof Shells are a poorly studied and understood species. Other similar species feed primarily on algae, detritus, and carrion. Because they are sedentary, they use their extendable snout to reach food sources and are dependent on water movement to bring them food. They are sequential hermaphrodites, beginning life as males and transitioning into females. They reproduce sexually. The eggs sacs are brooded under the female’s shell. Beyond sometimes being an epibiont on other shells, their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. From a conservation perspective the Delicate Hoof has not been formally evaluated. However, they are fairly common with a wide distribution and should be consider to be of Least Concern.
Synonyms: None