What is Georgia’s State Shell? The Knobbed Whelk (Busycon carica)!
Christened the state shell in 1987, the knobbed whelk is a whorled shell. It grows to eight inches long at maturity. It displays heavy spines, many knobs, and an orange or red mouth. Minerals in Georgia coastal waters cause ocher striations on the sand-colored, semi-gloss surface. This marine snail shell appears all along Georgia’s shoreline, out to 30 feet of water.
Both the knobbed whelk and the lightning whelk have knobs on the edge of each whorl. The shell is dextral, meaning that it is right-handed. If the shell is held in front of the viewer, with the spiral end up. The opening faces the viewer, the opening will be on the animal’s right side. The shell is thick and strong and has six clockwise coils. The surface had fine striations, with a ring of knob-like projections protruding from the widest part of the coil.
Knobbed whelks grow to eight or nine inches in shallow water along the coast from Massachusetts to northern Florida. The knobbed whelk lives subtidally and is migratory, alternating between deep and shallow water, depending on the time of year.
During the weather extremes of the summer and winter months, these sea snails live in deep water.
In the milder weather of the spring and fall they live in shallow water, on near-shore or intertidal mud flats and sand flats.
On the shallow-water mud flats whelks prey on oysters, clams, and other marine bivalves. They wedge a bivalve open using the edge of their shell, and insert their long proboscis to eat the flesh of their victim.
Females lay strings of egg capsules attached by one end in the sand.
Photo provided by Ed Jackson.