Rugged Vitularia Shell, Vitularia salebrosa

Rugged Vitularia Shell, Vitularia salebrosa. Shell collected off the beach at Punta Chivato, Baja California Sur, May 2022. Size: 7.3 cm (2.9 inches) x 4.2 cm (1.7 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Phylogeny: The Rugged Vitularia Shell, Vitularia salebrosa (P.P. King, 1832), is a gastropod mollusk that is a member of the Muricidae Family of Rock Shells. The genus Vitularia is one of one hundred ninety-eight genera in this family, and there are six species in this genus. The species name salebrosa comes from the Latin word salebra, which means a rugged road, reflecting the concept of ruggedness or unevenness, like the surface of this shell.

Description: The Rugged Vitularia Shell is solid, and spindle shaped. It consists of about five whorls, with a single row of knobs at the shoulder. The spire is relatively high, and the shell may have several varices. The exterior texture may be smooth, wrinkled, or a combination of warts and dimples. The siphon canal is short and open. The outer lip of the aperture may be thin, but more often, it is thick and sculpted inside with denticles. The exterior of the shell is olive-brown or terra-cotta in color, often with white patches and/or brown spiral lines; the interior is shiny white. Rugged Vitularia Shells reach a maximum of 10.7 cm (6.2 inches) in length and 6.2 cm (2.5 inches) in height.

Habitat and Description: Rugged Vitularia Shells are found on rocks from the lower intertidal zone to depths up to 41 m (134 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent north of Cedros Island, Baja California, along the central and northwest coasts of the Baja Peninsula and north of Cabo Tepoca, Sonora, in the Sea of Cortez.

Ecology and Behavior: The majority of Muricidae Rocks are family are considered to be predators. However, the Rugged Vitularia Shells drill into their prey and feed so slowly that they are considered to be ectoparasites (parasitizing from the outside). Research has shown that these shells take at least 90 days, to feed on their host. In some cases, feeding can take more than 200 days. Rugged Vitularia Shells parasitize oysters and slipper shells. In turn they are preyed upon by crabs, fish, and sea stars. They are gonochoric and reproduce sexually, with internal fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. From a conservation perspective the Rugged Vitularia has not been formally evaluated. However, they are fairly common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: Murex salebrosus, Vitularia extensa and Vitularia salebrosa extensa.