Curator’s Corner

Museum, research, and collection updates from Dr. José H. Leal, plus Shell of the Week, which highlights a different species every other Friday. Most Shells of the Week are found in Southwest Florida.

Dr. José H. Leal serves as the Bailey-Matthews National Shell Museum & Aquarium’s Science Director and Curator. He received his Ph.D. in Marine Biology and Fisheries from the University of Miami and has served at the Museum since 1996.

The Tollin Wentletrap

Tollin Wentletrap, Epitonium tollini Bartsch, 1938, is one of the less common among the eight recognized species of local Wentletraps. Measuring a tad more than 0.5 inch in size, it differs from the more common Angulate and Humphrey Wentletraps by its slender shape, with a more acute spire angle (the angle formed by the “sides” of the shell.) The costae (“blades”) that comprise the bulk of the shell sculpture line up nicely along successive shell whorls. The operculum (“trapdoor”) in this specie

The Unequal Spoon Clam

The Unequal Spoon Clam, Periploma margaritaceum (Lamarck, 1801), is a rare find from the muddy, back-bay environments of Sanibel, Captiva, and neighboring areas. The shell is small (rarely reaching more than ½ inch in length), oval, thin, with a posterior keel that runs from the beak to ventral (“bottom”) of the shell valve. The area behind the keel is usually covered with a thick, dark periostracum. The shell valves are unequal, with the left valve more inflated, larger than and the overlapping

The Suppressed Vitrinella

At about 1/10 of an inch in diameter, the Suppressed Vitrinella, Cyclostremiscus suppressus (Dall, 1889), is one the many true micromollusks found on Sanibel and Captiva. A member of the family Tornidae, it has a circular, puck-shaped shell with three distinctive keels around the shell periphery. Well-defined grooves separate the keels from each other. The Suppressed Vitrinella is usually opaque-white or slightly translucent (shells of recently dead individuals). Its Latin specific name, supress

The Smooth Risso

The Smooth Risso, Zebina browniana (d'Orbigny, 1842), is one the many micromollusks found on Sanibel and Captiva, but the only one from the gastropod family Zebinidae found locally. Reaching not more than 0.2 inch in size, it qualifies as a true micromollusk, as, by definition, micromollusks are those having shells not larger than 5 mm, or about 0.2 inch. The shell shape is conical and, as the common, or vernacular, name implies, smooth and devoid of any sculpture, smooth. The shell is also tran

The Semisulcate Moon Snail

There are locally at least eight shallow-water species of the Moon Snail family Naticidae. The half-inch long Semisulcate Moon Snail, Sigatica semisulcata (J.E. Gray, 1839) is the second smallest of them. (The smallest is the Miniature Moon Snail, Tectonatica pusilla, measuring only about ¼ inch.) Semisulcate Moon Snails have egg-shaped, almost always pure-white shells. The species distinguishing feature, other than its relatively small size, is the presence of 2­­­–6 incised (“etched”) spiral l

The Carib Fossaria

This week I hope to surprise you by presenting a local freshwater snail. The vast majority of the species treated in this column dwell either in the marine or brackish-water (estuaries, “backbay”) realms. Once in a blue moon I may introduce a local freshwater species, those living in very low salinity environments such as some of the local in-island ponds and ditches. The Carib Fossaria, Galba cubensis (Pfeiffer, 1839) is one of the locally found freshwater snails. A pulmonate snail, it breathes

The Olive Nerite

A rare find locally on Sanibel-Captiva, the Olive Nerite, Neritina usnea (Röding, 1798), is relatively common in other parts of Florida and the Gulf of Mexico. The species is very variable in color and shape, but usually presents a pattern of closely set, wavy axial (“vertical”), dark lines against a light-olive background. The 0.6-inch shell in the photos was found on the beach of Captiva by Kimberly Nealon, on the first weekend after Hurricane Irma’s visit. Given that the species prefers to li

The Yellow-spot Scallop

I am including this entry for the Yellow-spot Scallop, Spathochlamys benedicti (Verrill & Bush [in Verrill], 1897), hoping to find from the readers of this column whether anyone has found it on local beaches. The species, which has a broad distribution in the western tropical Atlantic Ocean, is known from samples collected offshore of Sanibel, in depths around 90 feet. This species, at about 0.5 inches in size, is one of the smallest scallops from our part of the Gulf of Mexico. The shell has ab

The Tea Drillia

The Tea Drillia, Cerodrillia thea (Dall, 1884), is another local, small gastropod that may, due to its size, be missed by most casual shell seekers. Its shell reaches 0.5 inch in length, and is elongate and attractive. The shell sculpture consists of 7–9 slightly curved, axial (parallel to the main shell axis) ribs. The shell is light-brown (“tea-colored”), with a very thin grayish-green periostracum (outer, preteinaceous shell layer) present mostly between the axial ribs. The species belongs in

The Adams Miniature Cerith

The Adams Miniature Cerith, Seila adamsii (H.C. Lea, 1845), is a small gastropod not uncommon on the barrier islands of Southwest Florida. Its shell reaches 0.5 inch in length, and is slender, narrowly conical, with an elegant sculpture of three spiral cords. The shell color is orange to dark-brown. Despite its small size, Adams Miniature Ceriths are as handsome as some larger species. Casual beachcombers may walk the beaches for years and not notice them, but small shells and micromollusks repr