Shell Guide
for South Carolina Beaches
Shelling is a popular past-time on beaches worldwide and S.C. is no exception. Many people include them as home decor and enjoy the memories of the ocean.
While I certainly love shells as mush as the next gal it’s important to remember to never collect live shells and that dead shells are habitat for numerous species, not just hermit crabs! Over time shells may be broken down by wave action and ground into smaller and smaller pieces until they finally add to the sand we all enjoy running our toes through on the beach. I challenge all who read this to think twice before collecting every shell in sight and instead choose a few of your favorites and leave the rest for the sea.
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Shells are in the mollusk phylum along with their cousins the cephalopods (squid, octopus, etc.). This guide will be divided into two general sections to make identification easier.
Bivalves have two shells connected by a hinge (think clams, oysters) while univalves have only one shell (think snails). It can be difficult to discern one from the other in the beginning as we often find only one of the half of a bivalve on the beach, but with a little practice you’ll be identifying shells no time!
Note: At this time this page only includes the most common shells and is meant to get you to the general group your shell is in. Some groups such as arcs have numerous species. See below for further resources to identify to species if you’d like.
Bivalves
Eastern Oyster
Pen Shell
Incongruous Arc
Giant Atlantic Cockle
Tellin
Calico Scallop
Jingle
Tagelus
Quahog
Univalves/Gastropods
Gastropods, meaning “stomach-footed”, are a class of mollusks more commonly referred to as snails. Gastropods are found on land and in both fresh and salt water. Many snails have a hard plate called an operculum that acts as a protective door, sealing the animal into the shell making it less susceptible to predation. Like bivalves, snails may be herbivores or carnivores. Most of the snails found on our beaches are carnivores and use their radula to drill into prey (moon snail) or may open bivalves with the sharp edge of their shell and operculum (whelks).
Check back soon for a section on Who Eats Who.
The most common whelk on SC beaches is the knobbed whelk, followed by the channel and lightning whelks. To tell the knobbed and lightning apart (some find them to be similar in appearance), do the sand test: stick the pointy end of the shell in the ground and if the opening is on the right = knobbed and left = lightning! It should be noted that we do not have any true conchs in SC; conchs are herbivores with a wider lip to the shell unlike our carnivorous whelks. The horse conch is out to confuse you with it’s common name!
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Augers, oyster drills, mussels, clams
For other beach treasurers click here!
Additional References:
Audubon Field Guide – Extremely comprehensive, but bulky to carry on walks
Why are some shells of the same species different colors?
Black shells have become stained from resting in mud. White shells are found washed up on beaches or shell rakes where the sun bleaches them white. And some shells are a combination!
