Neobernaya spadicea

Lore & Background

The chestnut cowrie inhabits kelp beds and rocky surfaces in intertidal and subtidal zones, often found under rocks and in protected crevices. Its range extends from Monterey, California to Isla Cedros, Baja California, with common populations in Southern California, particularly around the Channel Islands. North of Santa Barbara, California, the species is rare.

The shell features a large, irregularly shaped caramel-colored spot with a dark brown border on top, while the rest of the shell, including the bottom, is white. A narrow aperture with small teeth runs the length of the underside. The shell grows until the cowrie reaches adult form, then stops. When undisturbed, the orange-spotted mantle extends around and can completely cover the shell. The foot is white. The glossy finish results from enamel secreted by the edges of the mantle; retracting and extending the mantle acts as a buffer, polishing the shell while depositing new enamel.

Reader's Guide

The chestnut cowrie holds significance as the sole cowrie species in the eastern Pacific, marking a distinct biogeographic boundary. Its glossy shell, produced by mantle secretions, is a defining characteristic of the family. The species is an opportunistic feeder, consuming a wide variety of organic matter including anemones, sponges, tunicates, eggs, dead organisms, plants, and detritus. Reproduction occurs during summer months, with batches of approximately 100 egg capsules, each containing several hundred eggs. The chestnut cowrie's presence in intertidal and subtidal zones, particularly in kelp beds and rocky areas, makes it a component of the coastal marine ecosystem from central California to Baja California. Its rarity north of Santa Barbara and commonality around the Channel Islands highlight localized population patterns.

Did You Know?

• The chestnut cowrie is the only cowrie species found in the eastern Pacific Ocean.
• The adult shell ranges in size from 40 to 65 mm.
• Each batch of eggs contains approximately 100 egg capsules, each with several hundred eggs.