Neobernaya spadicea (Swainson, 1823) (the “chestnut” cowrie), a member of family Cypraeidae, lives today only from Monterey Bay, Monterey County, California to southern Baja California Sur, Mexico. Cowries are marine gastropods found most commonly throughout the world in warm to tropical, shallow-marine waters. There are approximately 260 living species and many extinct species. Living cowries are among the favorites of sea-sea collectors because the cowrie shell is glazed (highly polished) and can have an array of beautiful colors and patterns. The geologic record of cowries is from the Jurassic to Recent. There are many Cenozoic cowries in the fossil record of the west coast, and most of them lived during times that were much warmer than today in this area.
The cowrie now known as Neobernaya spadicea (Swainson, 1823) was misidentified as to genus [e.g., Cypraea], until 2000, when it was recognized as actually belonging to genus Neobernaya. The fossil record of N. spadicea is Pliocene to Recent.
The following four images are of a specimen of N. spadices (49 mm length [distance between the posterior and anterior]; 29 mm width; and 24 mm height [distance between the base/bottom and the dorsum/top]. This specimen was collected in beach drift from a beach in Santa Barbara County, Southern California.
The name “spadicea” refers to the chestnut-brown color although there is a variation of the color of the top surface of the shell of this species: from chestnut brown to rust to red. The base (lower surface) and lower parts of its sides of the shell, however, is white.
This species lives in moderately cool waters, from intertidal to 50 m depth, especially the sublittoral zone near ledges and rocky areas. It lives in the near vicinity of forests of the giant kelp Macrocystis pyrifera, where this gastropod preys on bryozoans, hydroids, sponges, anemones, tunicates, and molluscan eggs. At least one of octopus apparently feeds on N. spadicea.
After hatching from eggs, the young of N. spadicea transition into a free swimming stage (veliger), but they are slow swimmers and many settle quickly to the ocean floor and begin to grow into adults. The juvenile stage of this species, like all cowries, is called the “bulla” stage. Its shell is very thin and elongate. Eventually, this stage will transition into the glazed over, strong shell of an adult. The maximum, full adult shell size is about 80 mm length.
Interior of a N. spadicea specimen showing the juvenile bulla stage. The entire specimen (length 46 mm, width 27 mm) was collected also as beach drift from a beach in Santa Barbara County, Southern California.
Much of the information used in this post is from the following very useful and up-to-date reference:
Groves, L.T. 2019. The family Cypraeidae Rafinesque, 1815, in the northeast Pacific: One spectacular species. Zoosymposia 13:131–138 (James H. McLean Memorial Volume).
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