Prickly cockles are a distinctive, easily identified species. They grow to
approximately 3 inches, with the somewhat elongate shell reaching 2 inches
in height. The shell has 27 - 31 radial ribs, each with many raised scales
covering the surface. Color is variable, ranging from white to
gray, with patches of yellow, purple, brown, or brick red. Shell
interior is generally glossy with bright hues of salmon, purple or red.
Prickly cockles are a common shallow subtidal species. They are much
more common on the west coast of Florida than on the east coast, though they
can be fairly common around inlet areas of the Indian River Lagoon.
Prickly cockles may be confused with Trachycardium muricatum, the yellow cockle. The
two are distinguished in that yellow cockles are generally more oval in
have 30 - 40 radial ribs. These ribs are only moderately scaled,
and are somewhat smooth at the
center of the shell. Further, the interiors of yellow cockle shells may
range in color from white to bright yellow.
Prickly cockles are found from North Carolina south through Florida and
the West Indies. They are common in shallow water areas of the Indian
River Lagoon, especially around inlets.
The prickly cockle,
Trachycardium egmontianum, from the
Indian River Lagoon. Photo courtesy of K.
Hill, Smithsonian Marine Station.