Mollusks

Shell of the Week: The Atlantic Diplodon

Diplodonta punctata is a small clam that reaches only about 19 mm (3/4 inch). The Atlantic Diplodon belongs to the relatively small bivalve family Ungulinidae. Its shell is inflated (“swollen”), with a sculpture of fine growth lines and hinge with very small teeth. The species is found in the Gulf of Mexico and from North Carolina through the Caribbean Sea south Venezuela, and in Bermuda. Illustration created in December 2020 by James F. Kelly for the Museum’s Digital Imaging Project.#diplodonta

Shell of the Week: The Deep-water Dove Snail

Astyris profundi is a small gastropod that reaches about 8 mm (about 0.31 inch). The species is found in depths between 200 and 500 meters (about 657 and 1640 feet). Its shell is relatively smooth, with most of the sculpture limited to spiral threads around the base and around the siphonal canal (the “bottom” of the shell in the images). The shell is clear, somewhat translucent. The Deep-water Dove Snail is found from off North Carolina to northern Cuba, and the species apparently is not found i

Shell of the Week: The Knave Marginella

Prunum torticulum Dall, 1881, is a small gastropod that reaches only 11.5 mm. The species can be distinguished from other species of Prunum by its unusual aspect (the word torticulum derives from the Latin word for “crooked,” “twisted,” or “arched”). In the original description of the species, Smithsonian zoologist William Healey Dall observed that “the twist gives the shell a very peculiar and highly characteristic appearance.” In addition to that, the shell spire is usually covered with a rela

The Gills of Bivalves

Did you know that the gills of mollusks are called ctenidia? Ctenidia (singular ctenidium) consist of filaments arranged in comb- or feather-like structures. In aquatic mollusks, the ctenidia are the main respiratory organs, absorbing oxygen dissolved in the water for the metabolic functions of those animals.The vast majority of bivalves are filter-feeding species: they strain the water to capture their food, usually microalgae or other types of microorganisms. In an interesting twist of evoluti

The Florida Regal Doris

Felimare picta is one of the nudibranch sea slugs (shell-less gastropods with external gills) found offshore along Sanibel Island and other parts of Southwest Florida. Reaching 13 cm (about 5.1 inches), it is one of the largest nudibranch species in the western Atlantic Ocean. It is also one of the most attractive, showing an elegant color pattern of yellow lines and elliptical markings against a dark blue, sometimes almost black, background. The gills are visible as a set of feather-like projec

2023 Bivalves Workshop: A Success Story

On November 8-10, I taught the 2023 Marine Bivalves workshop, promoted by the Florida Association of Aquatic Biologists (FAB) at the University of Tampa’s Marine Science Field Station, in Tampa. The workshop dealt with the natural history and identification of local marine bivalve mollusks. The 2.5-day event was attended by marine biologists from, among other institutions, the University of Tampa, University of South Florida, United States Geological Survey, and Smithsonian Marine Station at For

Shell of the Week: The White-spot Dove Snail

Mitrella ocellata is a small (13 mm, or 0.5 inch) marine snail from the dove snail family Columbellidae. Its shell shows a color pattern of white spots set on a chestnut-brown background, and a set of denticles on the outer shell lip. The species is found in the tropical western Atlantic Ocean from east Florida to southeastern Brazil. The species is found also on the mid-Atlantic oceanic islands of Trindade, Ascension, and Santa Helena. Illustration by James F. Kelly.#mitrellaocellata #mwhitespo

Florida United Malacologists 2024

Save the Date! The next meeting of Florida United Malacologists (FUM) will take place on Sanibel Island, Florida, on Saturday, April 13, 2024. The one-day gathering brings together researchers, collectors, students, citizen scientists, and enthusiasts interested in a broad range of mollusk-related topics. The event is free for registrants, but you must be registered to attend. Registration will start on January 1st, 2024. Read more about previous FUM events here. We hope to see you at FUM 2024!

Here to Stay!

Since the discovery of the Thrush Cowrie, Naria turdus, in Florida in December 2022*, several other findings of the species have been informally reported for the east coast of Florida, most between Palm Beach County and Key West in the lower Florida Keys. The Thrush Cowrie originates from the Red Sea and western Indian Ocean, and had been introduced to the Mediterranean and Caribbean seas. One of the most recent sightings of the species took place in the same general area as that of the first fi

Shell of the Week: The Gulf Stream Miter

Isara straminea is a predatory gastropod of the miter family Mitridae that reaches 30 mm (about 1.2 inches). The species is found in relatively shallow water from off North Carolina, Gulf of Mexico, Caribbean, south to southeastern Brazil. The shell has a characteristic sculpture of revolving spiral cords, and is usually white or white with large, irregular light-brown spots. The illustration was created by Chris Kovaz for the Museum’s Digital Imaging Project.#isarastraminea #gulfstreammiter #mi