Mollusks

Shell of the Week: The Common Violet Snail

Janthina janthina (Linnaeus, 1758) measures up to 38 mm (about 1.5 inches) in height. The species is a member of the open-water, surface-dwelling community known as the neuston. Violet snails drift on the ocean surface using a raft of bubbles, feeding on other members of the neuston community such as the hydrozoans By-the-Wind-Sailor (Velella velella) and the Blue Button (Porpita porpita). The snail’s dependence on a raft of bubbles affects its posture on the water: they rest upside-down on the

Shell of the Week: The Coffee Bean Trivia

Pusula pediculus (Linnaeus, 1758) measures up to 22 mm (about 0.87 inch). The shell outline in trivias is elliptical, with an etched furrow along dorsal middle line. Trivias resemble cowries, but the sculpture of strong radial ridges sets them apart. The Coffee Bean Trivia usually lives on coral rocks in association with tunicates (e.g., sea pork.), and the species is not found along the shores of Southwest Florida.

FUM 2022: Save the Date!

The twelfth meeting of Florida United Malacologists (FUM) will take place on Saturday, February 5, 2022, at the Bailey-Matthews National Shell Museum on Sanibel Island, Florida. The one-day gathering brings together researchers, collectors, citizen scientists, enthusiasts, and students interested in a broad range of mollusk-related topics. FUM 2022 follows the pattern of similar, informal gatherings such as BAM (Bay Area Malacologists), SCUM (Southern California United Malacologists), MAM (Mid-A

Shell of the Week: The Blackberry Drupe

Claremontiella nodulosa (C.B. Adams, 1845) is a member of the family Muricidae, the same groups that include the local drills and murexes. The Blackberry Drupe shell reaches about 25 mm mm (about one inch), and its surface is entirely covered with round, black beads; the overall effect evokes a drupe, in this case a blackberry. The shell is also very thick shell in relation to its overall size. Notice also the white “teeth” inside the shell aperture. Blackberry Drupes live in shallow water, and

Cowrie Larvae Hatch at Museum!

One of the Arabian Cowries (Mauritia arabica) in our Living Gallery recently laid egg capsules. We moved some of the egg capsules to our lab and, six days later, larval cowries emerged from the capsules! Although some species of mollusks spend most of their early development inside egg capsules, many undergo a free-swimming larval phase before settling to the bottom as adults. These swimming "toddlers" are known as veliger larvae, a type of larva found only in mollusks. Most veliger larvae are c

Shell of the Week: The Beautiful Miter

Vexillum pulchellum (Reeve, 1844) is a member of the family Costellariidae that may reach 23 mm (about 0.9 inch). Its shell has a sculpture of strong axial (“vertical”) ribs and an elegant color pattern of an orange or salmon-pink background and a single, narrow spiral band of lighter color, which is in turn crossed by short dark-brown bars. The species is found in Florida and the Caribbean. (A large reproduction of this illustration is displayed in the In Focus exhibition at the National Shell

Shell of the Week: The Noble Wentletrap

Reaching about 35 mm (about 1.4 inches) in size, Sthenorytis pernobilis (P. Fischer & Bernardi, 1857), can be found in deep water around Florida and the Gulf of Mexico. Thanks to its elegant proportions and exquisite sculpture of prominent blades, or costae, the species is an eternal favorite among shelling enthusiasts. (A large reproduction of this illustration is displayed in the In Focus exhibition at the National Shell Museum.) #sthenorytispernobilis #noblewentletrap #epitoniidae #gulfofmexi

Shell of the Week: The Smooth Sundial

Reaching only about 14 mm (about 0.6 mm) in diameter, Psilaxis krebsii (Mörch, 1875), is one of the smallest species in the sundial family Architectonicidae. The Smooth Sundial has an amphi-Atlantic distribution, living in moderately deep water from Florida to Colombia in the western Atlantic, and the Mediterranean Sea, Canary Islands, and off West Africa. (A large reproduction of this illustration is displayed in the In Focus exhibition at the National Shell Museum.) #psilaxiskrebsii #smoothsun

Extinction is Forever!

The Arc-form Pearly Mussel, Epioblasma arcaeformis (Lea, 1831), a freshwater bivalve originally from Alabama, Kentucky, and Tennessee, is one of the mollusks diagnosed as extinct in the Red List prepared by the International Union for Conservation of Nature (IUCN). The Red List classifies animals according to their conservation status, ranging from species of “Least Concern” to “Extinct in the Wild.” In this case, extinction was caused by habitat loss due to construction of dams and human encroa

Shell of the Week: The Channeled Sundial

Heliacus infundibiliformis (Gmelin, 1791) reaches 15 mm (about 0.6 inch). It has a “flattened” shell and a wide umbilicus (opening on shell base) and may reach about 15 mm (about 0.6 inch). The entire shell sculpture consists of beaded spiral cords. Sundials are usually associated with soft corals, and the Channeled Sundial is no exception. The species is found from the coast of Southeast Florida to the southern Caribbean. (A large reproduction of this illustration is displayed in the In Focus e