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.

Marine Mollusks and Global Warming

The question of how mollusks respond to climate change often comes up in interactions with our audience and the community in general. As temperatures gradually rise, researchers are investing more time and effort interpreting the effects of those changes onto biodiversity patterns in plants and animals. And mollusks are not an exception. For instance, in a compelling paper recently published in the Proceedings of the Royal Society B: Biological Sciences, Paolo Albano and his collaborators have s

Shell of the Week: The Antillean Caecum

Giving continuation to local species of the family Caecidae, today I present the Antillean Caecum, Caecum antillarum Carpenter, 1858. The small, curved, tube-like shell in this species is smooth, glossy in well-preserved specimens, and measures only up to 3.5 mm (about 0.14 inch). The structure opposite the aperture (shell opening), called the apical plug, is dome-shaped, hemispheric; shell color is white. The shell in the image was collected in 1998 by Lois Dunnam, at Gulfside City Park on Sani

Perfection from Disorder

We have discussed in the past the fantastic physical features of shell material. The structural properties of mother-of-pearl, also known as nacre, for instance, a material of great strength and resilience, have been tapped for uses in engineering, optics, electronics, and other hi-tech applications. Not all molluscan shells include a nacreous layer, though. When present, nacre is usually the internal shell layer, showing iridescent, always-shifting colors. (the shells of nautiluses and abalones

Shell of the Week: The Beautiful Caecum

At 2.5 mm (about 0.1 inch), Caecum pulchellum Stimpson, 1851 is a local member of the family Caecidae, a group of marine microgastropods that have spiral juvenile shells that become cylindrical in the adult stage. The juvenile shells of caecums actually “fall” at the inception of adulthood. The Beautiful Caecum has a shell sculpture of about 20 “rings” that are half as wide as the interspaces separating them. The color is white or tan. The image was taken with a Scanning Electron Microscope. #ca

Shell of the Week: The Virgin Nerite

At 12 mm (about 0.5 inch), Vitta virginea (Linnaeus, 1758) is another small nerite with rounded, smooth shell. The parietal shield (the flat area inside aperture) is crescent-shaped, white, and may bear a number of small, irregular teeth. The shell is very variable in color; the dominant color may be black, red, green, purple, with spots, wavy or zigzag lines, and bands of alternating colors. The single shell of this species from Sanibel present in the Museum collection was collected in 1950 at

Wentletrap Triumvirate

Like wentletraps? Here are from left: Angulate, Humphrey, and Tollin wentletraps (from left, Epitonium angulatum, E. humphreysii, and E. tollini), .three species living along the coast of Southwest Florida. Observe how the Humphrey Wentletrap has a much darker operculum (the “trapdoor”) when compared to the two other species! And Tollin Wentletrap is the smallest and daintiest among the three species, usually reaching only about 5 mm (or 0.2 inch; the photos are not to scale). On Sanibel Island,

One Nerite, or Two?

The introduction of DNA sequencing as a taxonomic tool in the 1980s started a revolution that keeps transforming the classification of mollusks and opening the way for better species delimitations. Molecular systematics has shown time after time not only that what we believe to be separate species are just one and the same, but also that what may be perceived as a single species may actually be two or more! Take, instance, the article by Cristiane Barroso, from the Universidade Federal do Ceará

Shell of the Week: The Elliptical Sportella

Basterotia elliptica (Récluz, 1850) is one of the rarest species of bivalves in our area. The Museum collection only houses only one valve (half-shell) of the species! This nondescript “little white clam” grows to be around 10 mm (about 0.4 inches), and is very similar to its locally found, “sister” species, the Square Sportella (presented last week in this column.) The Elliptical Sportella, however, has a more elongate shell (not necessarily “elliptical’!) The slightly damaged valve illustrated

Life Imitates Art?

In the photos below, the image at left shows the distinctive hinge teeth of the Southern Quahog, Mercenaria campechiensis (Gmelin, 1791), as well as the distinct “scars” that hint at areas of contact between the living clam’s muscles and its shell. And you may be wondering about the image on the right? Well, the story goes like this: A few years ago, after taking the photo of the hinge, it looked to me like two people facing each other. But I was left with a lingering feeling that I had seen tho

Shell of the Week: The Square Sportella

Basterotia quadrata (Hinds, 1843) grows to be around 14 mm (about 0.55 inches), and has a “squarish” shell with irregular and variable outline. The shell has a slightly granular (“pebbly”) sculpture, and its hinge is garnished internally with one cardinal tooth on each valve. A ridge is present near the posterior margin. The presence of the species on Sanibel is represented in the Shell Museum collection by loose valves found in 2015–2016 by Susan J. Hewitt on Turner Beach. #squaresportella #bas