Veined Olive Shell, Oliva spicata

Veined Olive Shell, Oliva spicata. Shell collected off the beach of Bahía Concepción, Baja California Sur, October 2019. Size: 4.1 cm (1.6 inches) x 1.9 cm (0.7 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Veined Olive Shell, Oliva spicata (Roding, 1798), is a gastropod mollusk that is a  member of the Olividae Family of Olive Shells. The genus Oliva is one of eleven genera in this family, and there are one hundred and twenty species in this genus. They are also known as the Spicate Olive Shell and in Mexico as Oliva Venosa. The species name spicata comes from the Latin, meaning “spiked”. There is one accepted subspecies of this shell, Oliva spicata spicata.

Description: Veined Olive Shells vary significantly in color, pattern and shape, with individual shells being wider or more tapering than others. They have moderately high, pointy, spires. There is a defined channel where the body whorl meets the spire. The anterior of the shell is marked with ridges spiraling from the interior, and the inner lip of the aperture is well marked with short ridges. The exterior of the shell is cream, brown, or yellowish-gray and marked with brown that can include specks, spots, bands, or chevrons.  Veined Olive Shells reach a maximum of 8.5 cm (3.3 inches) in length and 3.9 cm (1.6 inches) in height.

Habitat and Distribution: Veined Olives reside on sand substrate from the intertidal zone to depths up to 29 m (95 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 from north of Magdalena Bay, Baja California Sur, along the central and northwest coasts of the Baja Peninsula. Veined Olive Shells are thought to be the most common Olive Shell in the Gulf of California, but due to the wide variation between individual shells they can be difficult to identify.

Ecology and Behavior:  Veined Olives are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in the Olividae Family are predatory carnivores that feed on bivalves, crustaceans, echinoids, holothurians, and gastropods, including other olive shells. 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 Veined Olive has not been formally evaluated. However, they are common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: Oliva oniska, Porphyria litterata, and Porphyria spicata.