Mollusks

Shell of the Week: The Flat Tree Oyster

Not a true oyster, Isognomon alatus (Gmelin, 1791) is a rare find along the coast of Southwest Florida, with very few examples from our immediate area present in the larger American museum collections. The species is common in the Tampa Bay area and along the east coast of Florida. There are a couple of holdings in our collection from Marco Island, but only recently we confirmed the presence of the species in Lee County. Lorin Buckner found and photographed a couple of Flat Tree Oysters near San

Shell of the Week: The Banded Transennella

Transennella stimpsoni Dall, 1902 reaches 14 mm in length. The rounded-trigonal shell is smooth except for very low commarginal (“concentric”) ridges. The shell color is usually white, often with brown or violet chevron-like markings, internally infused with purple. The outer shell layer, or periostracum, is varnish-like, yellowish. Compare with the locally occurring Transennella conradina, which is more pointed posteriorly and lacks the purple color. Also known as Stimpson's Transennella. This

Shell of the Week: The Hairy Triton

Monoplex pilearis (Linnaeus, 1758) is a relatively common tropical western Atlantic species that is also present in the tropical Indian and Pacific oceans, including Polynesia and Hawaii. Hairy Tritons may reach 140 mm (5.5 inches) in some parts of its distribution. The long-lasting pelagic (open-water) larvae in the species allow for ocean crossing at the larval stage, one of the reasons for its broad geographical distribution. You can see the larval shell preserved as the protoconch (at the ap

Shell of the Week: The Scaly Scallop

Caribachlamys sentis (Reeve, 1853) is a shallow-water scallop (family Pectinidae) that may reach about 45 mm (about 1.8 inch). The shell is fan-shaped, with one auricle (the “little ear”) much larger than other, the left valve is reddish to brown, evenly colored, right valve of roughly the same color. The basic sculpture pattern includes about 18, regularly spaced, radial ribs. The species is present in South Florida, Florida Keys, Caribbean down to South America. (A large reproduction of this i

Shell of the Week: The Atlantic Trumpet Triton

Charonia variegata (Lamarck, 1816) is one of the largest gastropods found in the Atlantic Ocean. Atlantic Trumpet Tritons can be found from North Carolina to Brazil, and feed on, among other large sea stars, the red cushion sea star Oreaster reticulatus. The Museum displays the world record-size shell of this species, a shell measuring 388 mm (about 16 inches), collected off Fortaleza in northeastern Brazil. (A large reproduction of this illustration is on display in the In Focus exhibition at t

A Gem of a Land Snail!

Look at this little green gem! Simpulopsis rufovirens (Moricand, 1846) was photographed by Alex Popovkin, working in the State of Bahia, Brazil. Notice how the color of the shell matches the color of the leaf on which it crawls. The early whorls are yellowish-brown, but the adult shell is a bright green! The entire shell surface is corrugated, which probably helps reinforce the shell against crushing by predators. The shell in this species is thin, and may grow to be a little larger than 0.5 inc

Museum Collection Reaches Out Globally

Today I want to do something different and discuss a powerful resource for those of us interested in molluscan biodiversity. The image below shows the Museum’s landing page on the Global Biodiversity Information Facility (GBIF). That includes a map showing our general reach (for lots with geographic coordinates) and a quick access to our gallery of images, currently with 2,786 multiple-photo images (see image on bottom of page.) Based in Europe, GBIF is one of large data aggregators for natural

Shell of the Week: The Magnum Prickly Cockle

Acrosterigma magnum (Linnaeus, 1758) reaches about 50 mm (about 2 inches). This is one of the largest and more impressive species of the cockle family Cardiidae found in the western central Atlantic. The species is found in Florida, the Florida Keys, the Caribbean, northern South America, and in parts of the Gulf of Mexico (but not on the beaches of Southwest Florida.) The Magnum Prickly Cockle is notable for the delicate hues and smooth surface on the sculpture of radial ribs. (A large reproduc

Shell of the Week: The Little Knobby Scallop

Caribachlamys pellucens (Linnaeus, 1758) measures up to 37.4 mm (about 1.5 inches) in height. The shell has about 8–10 radial ridges festooned with small knobs or thick scales. The valves in this species may show strong yellow hues internally. We assume that the coloration is not advantageous for visual communication of any kind, because other animals cannot see the inside of a shell. Bright colors and strong patterns usually serve to warn predators of poisonous substances present, or to attract

Shell of the Week: The Red-ribbed Scallop

Aequipecten glyptus (A.E. Verrill, 1882) measures up to 75 mm (about 3 inches) in height. The Red-ribbed Scallop is found along the Eastern Seaboard of the US, from Cape Cod to Texas. It is a moderately deep-water species, usually living in depths from 130 to 860 m (about 430 to 2,820 ft). The thin, flattened shell bears typical, red-colored, relatively broad ribs. The internal surface of valves shows narrow ribs that may serve to reinforce the shell. (A large reproduction of the illustration be