Mollusks

The Colorful Moon Snail

The Colorful Moon Snail, Naticarius canrena (Linnaeus, 1758), belongs in the category of "most desirable shell finds" locally. Colorful Moon Snails are in the same group (family Naticidae) as the Shark Eye, but unlike this latter species, which has a brown, proteinaceous, "soft" operculum (plural opercula), Colorful Moon Snails have opercula made of shell material, or calcium carbonate. The sculpture of the operculum in the family Naticidae is important in the classification of the different spe

The Spiny Paper Cockle

The Spiny Paper Cockle, Papyridea lata (Born, 1778), belongs to family Cardiidae, as do its larger and heavier cousins, the Spiny, Egg and Giant Cockles. Spiny Paper Cockle shells are not uncommon on the beaches of Sanibel and Captiva. The shell is relatively thin, delicate, with radial (oriented from the beak toward the shell margin) ribs that bear fine, saw-tooth-like scales. The species is closely related to Papyridea soleniformis (also known as a Spiny Paper Cockle), differing from that by d

The Florida Spiny Jewel Box

The Florida Spiny Jewel Box, Arcinella cornuta Conrad, 1866, is a relatively common species in our area, and loose valves may be found after storms on the beaches of Sanibel and Captiva. As it happens with many bivalve species, whole shells, or paired valves, however, are more difficult to find. Spiny Jewel Boxes show delicate and variable color patterns, and the species name derives from the hollow spines present on the shell. The complete shells shown in the photos were collected by Smoky Pays

The Pristis Egg Cockle

The Pristis Egg Cockle, Laevicardium pristis (Bory de Saint Vincent, 1827), is closely related to last week's featured shell, the Common Egg Cockle. Egg Cockles are so called because of their smooth, egg shell-like shells. Reaching almost 3 inches in size, the Pristis Egg Cockle differs from the Common Egg Cockle by having a more inflated ("fatter") shell, and a much more conspicuous, stronger set of hinge teeth. The shell in the image was collected on the east end of Sanibel by Museum volunteer

The Common Egg Cockle

The Common Egg Cockle, Laevicardium serratum (Linnaeus, 1758), belongs to the Cockle family Cardiidae, a group of bivalves represented locally by at least nine species, including the Florida Prickly Cockle and the Atlantic Giant Cockle. Egg Cockles are so called because of their smooth, egg shell-like shells. Fully grown Common Egg Cockles typically measure a little less than two inches, and the scientific name of the species alludes to the finely serrated internal surface of the shell edges. An

The Squared Turrid

The Squared Turrid, Glyphoturris quadrata (Reeve, 1845), belongs to a relatively obscure family of marine gastropods, the Mangeliidae. Little is known about the Squared Turrid biology and feeding habits, but shells or the species are not uncommon along the shores of our barrier islands. Fully grown shells typically measure about 8 mm (1/3 inch). The two shells in the photos represent, on the left, a fully mature individual, and, on the right, an immature one. The main difference, other than the

The Zigzag Scallop

The Zigzag Scallop, Euvola ziczac (Linnaeus, 1758), lives offshore along the coast of Southwest Florida and other parts of the tropical and subtropical western Atlantic. Its shell is circular, and the two half-shells, or valves, are strongly dissimilar, with the lower valve strongly concave, and the upper valve flatter, slightly convex. The valves are also remarkably different in color; with the top, flat valve being colorful, usually displaying a pattern of brown or reddish-brown radial bands a

The Beau’s Vitrinella

Beau's Vitrinella, Cyclostremiscus beauii (P. Fisher, 1857), at about 12 mm in diameter (about 0.5 inch), is most likely the largest local member of the micro-gastropod family Tornidae, commonly known as Vitrinellas. Small sizes, sometimes never reaching beyond 1/8 inch, and strong similarity among species render Vitrinellas difficult to study, but the "larger" size, characteristically "keeled" shell outline, and typical spiral cords make Beau's Vitrinella relatively easy to identify. This speci

The File Fleshy Limpet

The File Fleshy Limpet, Lucapinella limatula (Reeve, 1850), is one of the three species of Keyhole Limpets (family Fissurellidae) that may be found along the barrier island of Southwest Florida. It has a relatively small shell (about 10 mm, or a little less than an inch), with a relatively large "keyhole" orifice. As in other Keyhole Limpets, the orifice helps direct waste water away from the snail's head and gills. File Fleshy Limpets have "rays" of colors ranging from red to brown set against

The Delicate Ark

The Delicate Ark, Fugleria tenera (C.B. Adams, 1845), is an uncommon western Atlantic member of the Arcidae, a family of marine bivalves that also includes the Turkey Wing and the Transverse Ark, among others. The delicate Ark may reach slightly more than one inch (25 mm) in size. It differs from others, related species by its thin shell, with an alternating pattern of thicker and thinner radial ribs, which are in turn crossed by concentric ridges. Living delicate Arks have a hairy, rich periost