Mollusks

The Common Atlantic Marginella

The Common Atlantic Marginella, Prunum apicinum (Menke, 1828), has a shell that may reach 10 mm (almost half an inch). The shell is pear-shaped, with a highly polished surface. The outer lip of the shell is adorned with two or three darker spots. The shell of live individuals is translucent, almost transparent, revealing colors and patterns on the animal’s body within. The shell will become opaque after the death of the animal. The species is very common in the seagrass beds present all through

The Angulate Wentletrap

The Angulate Wentletrap, Epitonium angulatum (Say, 1831), is the most prevalent (and variable) within the many species of the family Epitoniidae present on Sanibel and other parts of the eastern Gulf of Mexico. The species may reach up to 25 mm in length (about an inch). Again, as it is true for other local species of Wentletraps, including the one presented in this column last week, the Humphrey Wentletrap, it is found most abundantly on the eastern half of the island, from the Lighthouse to Gu

The Humphrey Wentletrap

The Humphrey Wentletrap, Epitonium humphreysii (Kiener, 1834), is one of the many species of the family Epitoniidae present on Sanibel and other parts of the eastern Gulf of Mexico. As is true for other species of Wentletraps, it may be found most abundantly on the eastern half of the island, from the Lighthouse to Gulfside City Park Beach. Wentletraps are known to feed on soft corals, and these are known to live in the relatively calmer waters of that part of the island. The live Wentletrap in

The Lace Murex

The Lace Murex, Chicoreus dilectus (A. Adams, 1855), is one of the most desirable and collectible shells from the barrier islands of Southwest Florida. The species may reach two inches in length. Lace Murexes feed on other mollusks, and will drill on the shell surface or chisel at the shell edge of clams and other bivalves in order to reach the soft tissues of the prey. Like many local species of mollusks, Lace Murexes lay egg capsules that help protect the eggs and embryos until is time for the

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