Broad-ribbed Carditid
Cardites floridanus (Conrad, 1838)
The Broad-ribbed Carditid is a common shell on S. Hutchinson Island beaches. On an average shelling day you will find several of them. They have a variety of color but most have red lines on off-white or gray.
Two (enlarged) Broad-Ribbed Carditid from S. Hutchinson Island (February, 2021)
Harry Lee: This species doesn't occur much further North on the FL east coast, but it is found on the shores of virtual all of the Gulf of Mexico.
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Family Carditidae
Cardites floridanus
(Conrad, 1838)
Broad-ribbed Carditid
Shell size to 40 mm; shell thick, solid, heavy, ovate. Sculpture of about 15-20 thick radial ribs crossed by concentric lines, which gives scaly appearance to ribs. Umbos close together. Lunule small. Color yellowish-white with blotches of reddish purple to brown. Interior white. Attaches by byssus to hard substrates. Common on mud flats. The yellow-tinged white shell, is infrequently found in the barrier islands of Collier County. This shell was collected by Amy Tripp on Kice Island. The composite image to the right shows a juvenile specimen measuring about 9 mm.
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The Broad-ribbed Carditid
José H. Leal May 19, 2017
The Broad-ribbed Carditid, Cardites floridanus (Conrad, 1838), is a common species on our shores. Its shell may reach about 1.5 inches in size, is very thick and relatively heavy for its size. With its sculpture of thick radial ribs, it vaguely resembles and might be confused with local species of Ark Clams. These latter, however, have a shell hinge consisting of many, small teeth that are similar in size; the Carditid, on the other hand, has a hinge with just a few teeth, all different from each other. The shell color is usually whitish with brown markings; an unusual form with yellowish color is sometimes found.