Mollusks

The False Angel Wing

A member of the Venus Clam family Veneridae, the False Angel Wing, Petricolaria pholadiformis (Lamarck, 1818), is so named because of its superficial similarity with the famous Angel Wing, and the fact that both burrow in compact mud or peat. However, the two species belong in separate families, with the False Angel Wing sharing its genetic and anatomical features with Venus clams. Among other differences between the “true” and the False Angel Wing are the size, much smaller (to two inches) in t

The Cayenne Keyhole Limpet

The Cayenne Keyhole Limpet, Diodora cayenensis (Lamarck, 1822), is a Keyhole Limpet often found on the beaches of Sanibel and Captiva. Like most representatives of the Keyhole Limpet family, Fissurellidae, this species shows the typical keyhole-shaped orifice that serves to reroute waste water away from the head of the animal (see picture on the right). The shell has a sculpture of numerous radial riblets of which every third or fourth is larger. The animal feeds on microalgae growing on rocks o

The Sharp-rib Drill

The shell of the Sharp-rib Drill, Eupleura sulcidentata Dall, 1890, has a “flattened” appearance, thanks to the blade-like varices (“ribs”) that occur alternately every 180° (every half-whorl). There may be two or three “bumps,” or nodes, present between last two varices. Color variable, often grayish-white to tan, sometimes with brown spiral bands. The shell is not uncommon on the barrier islands beaches, in particular after winter storms. Sharp-rib Drills use their teeth, as part of their feed

The Woven Lucine

The Woven Lucine, Lucinisca nassula (Conrad, 1846), is one of many species of the family Lucinidae found along the barrier islands of SW Florida (there are at least nine species found on local beaches—the Buttercup Lucine is probably the best known species). Lucinid clams are known to host chemosynthetic bacteria in their body tissues. These bacteria derive their life energy from simple chemical reactions (in contrast to plants, which derive their energy from sunlight, in the process known as ph

The Striate Piddock

The inch-long Striate Piddock, Martesia striata (Linnaeus, 1758), uses its rough shell to bore through wood. Piddocks use the front end of their shells in a semi-circular motion to drill through the wood, creating a long, cylindrical hole that is occupied for life by the animal. To collect their shells, look for “Swiss cheese-like” driftwood with the characteristic boreholes indicative of their presence. The Striate Piddock (left) and driftwood bored by Piddocks and other Clams, found on Sanib

The Arrow Dwarf Triton

The Arrow Dwarf Triton, Tritonoharpa lanceolata (Menke, 1828), is a very attractive, inch-long species found on the beaches of Sanibel and Captiva. It belongs in the family Cancellariidae, the same family as the more common, local Nutmeg. The Arrow Dwarf Triton occurs from North Carolina to Florida, the Gulf of Mexico, and Caribbean. A few have been found this season (2014–15), following the strong and extended periods of NW winds. A very similar species, Leal’s Dwarf Triton, Tritonoharpa lea

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 (