Mollusks

The Fat Dove Snail

At about 5 mm length (0.2 inch), the Fat Dove Snail, Parvanachis obesa (C.B. Adams, 1845) is one of the smallest local species of the Dove Snail family (Columbellidae). The live animals (on the right) were picked from stranded seaweed collected by Museum Marine Biologist Rebecca Mensch on Sanibel, in January 2015, and photographed by me at the Museum’s photography facility. As seen in the photo, Dove Snails (and other micro-gastropods) are capable of "crawling upside down" under the interface ai

Polycera hummi Abbott, 1952

Sea Slugs are gastropod mollusks that rely on chemical substances rather than on a shell for protection. The Sea Slug Polycera hummi Abbott, 1952, may reach about 20 mm (a little less than an inch). The species was named in 1952 by Shell Museum's Founding Director R. Tucker Abbott, and the animal in the photo was collected by our Marine Biologist Rebecca Mensch on Sanibel (on stranded sea weed) during the last week of January [2015]. This species may be found from North Carolina through Florida

The Atlantic Gray Cowrie

The Atlantic Gray Cowrie, Luria cinerea (Gmelin, 1791), is a relatively common species of Cowrie inhabiting shallow coral reef areas in the tropical western Atlantic. The species is not found, however, on the coast of Southwest Florida. As it happens with most species from the Cowrie family (Cypraeidae), the Atlantic Gray Cowrie bears planktonic larvae (their babies drift in the sea), which will grow until the moment of metamorphosis to their adult, bottom-living lives. The larval shell is very

The Lineate Dove Snail

The Lineate Dove Snail, Suturoglypta iontha (Ravenel, 1861) is a small gastropod that measures about 9 mm (about a third of an inch). A member of the Marine Dove Snail family Columbellidae, this species is found in sea grass beds and mud flats around the barrier islands of Southwest Florida. The Lineate Dove Snails are very variable in their color pattern, ranging from having fine lines to large spots of mahogany-, light- or yellowish-brown color. Small Dove Snails are known to feed on carrion (

The Rusty Dove Snail

The Rusty Dove Snail, Columbella rusticoides Heilprin, 1886, is not a common shell in the beaches of Sanibel and Captiva. Still, the Bailey-Matthews National Shell Museum collection houses about eight lots of the species from our barrier islands, collected between 1958 and 1967. The Rusty Dove Snail has the outer edge of the shell opening (the external lip) lined with tiny “teeth” (denticles), and the interspaces between the “teeth” are of darker color. The Rusty Dove Snail belongs in the family

The Specter Clam

Most bivalve mollusks (clams, mussels, oysters, etc.) are filter-feeders, straining large amounts of water to get their food, usually microscopic plants (phytoplankton). Exceptions to this are marine bivalves that prey on small critters such as crustaceans. These clams, known as septibranch bivalves, use a flexible, muscular "wall", or septum, which acts as a pump, creating a sudden negative pressure that sucks in nearby prey. The Specter Clam, Dilemma spectralis Leal, 2008, a deep-sea dweller f

The Fine-cut Nutmeg

The Fine-cut Nutmeg, Trigonostoma tenerum (Philippi, 1848), is a close relative of the local Nutmeg (Cancellaria reticulata (Linnaeus, 1767), but, unlike this latter, is a very rare shell on local beaches, living in deeper water in the Gulf of Mexico. The Fine-cut Nutmeg is also represented in the Florida fossil record. The shell in this image was found by former Shell Museum volunteer Lois Dunnan on Sanibel in December 2003, and a second Fine-cut Nutmeg was recently found on Blind Pass by avid

The Sanibel Turrid

Did you know that there is one species of marine snail named after Sanibel Island? The species is informally known as the “Sanibel Turrid,” and its scientific name is Crassispira sanibelensis. The species was first described by Smithsonian biologists Paul Bartsch and Harald Rehder, in 1939. The shell, which may reach 30 mm (a little more than an inch) in length, may be found in Southwest Florida and offshore in the Gulf of Mexico. For many years, this member of the family Pseudomelatomidae was m

The Stimpson Chimney Clam

Stimpson Chimney Clam, Rocellaria stimpsoni Tryon, 1861, is a small bivalve that measures about 18 mm (3/4 inch). Chimney clams bore into calcareous substrates such as coral and shells, where they form bottle-shaped dwellings of calcium carbonate (same material as shells). Found locally in valves of Cross-Barred Venus clams (center of image), Ponderous Arks (right), Quahogs, Jewel Boxes, and other bivalve and gastropod shells. In some extreme cases, the bivalve will form dwellings independent o

The Frond Oyster (Duplicated)

Shells of the Frond Oyster, Dendostrea frons (Linnaeus, 1758), can be found on island beaches usually attached to other objects. The shell outline is variable (see pictures), and usually conforms to the shape of the objects the oyster is attached to: very elongate when attached to Sea Whips, or rounded when living on rocks or other hard substrates. Claw-like projections "hook" the shells onto stems of Sea Whips. Frond Oysters belong to the same family as the edible oysters, the family Ostreidae.