Shells

Striate Piddocks: Stowaways for Life

The Striate Piddock, Martesia striata (Linnaeus, 1758) is one of the species of wood-boring bivalves found along the coast of SW Florida. Its shells may be found on local beaches, always confined to pieces of driftwood, such as the little (11 cm, or about 4.5-inch) log in the top part of the picture. The log is riddled with the remnants of a few hundred Striate Piddocks. They may grow to be more than an inch long, and have free-living larvae that live in excess of a month drifting in the ocean.

A Tumbling Snail

Most mollusk species are known only from their shell. But a peek at a beautiful shell can hardly reveal the life habits of the mollusk that made it. Take, for instance, the snail known as Gaza daedala Watson, 1879, a deep-sea species of gastropod from the South and Central Pacific. Reaching about 40 mm (about 1.5 inch), its attractive shell is smooth, iridescent, with delicate pearly hues, resembling the internal layers of abalones, pen shells, and some mussels. The species was named in 1879 by

Fabio Moretzsohn: 1964-2020

As some of you may already know, this week we lost a friend and well-known malacologist at the peak of his productive scientific and educational career. On Monday, January 6, 2020, Dr. Fabio Moretzsohn passed away, of complications from lung cancer. Fabio received his B.S. in Biology in 1987 from the University of São Paulo, in Brazil. In 1993, he received his M.S. in Biology from the University of the Ryukyus in Okinawa, Japan, and in 2003 was awarded his Ph.D. in Zoology from the University of

Shell of the Week: The Tampa Drill

Eupleura tampaensis (Conrad, 1846), reaches about 25 mm (an inch) and has a markedly angled shell outline, with a sculpture of about 12 strong axial (“vertical”) ribs crossed by equally strong spiral cords. Could be confused with two species of similar size and proportions: the Mauve-mouth Drill, Calotrophon ostrearum, which has a more rounded, “gentler,” not-angled outline and sculpture of axial ribs that are larger than the spiral cords, or the Gulf Oyster Drill, Vokesinotus perrugatus, which

Telltale Shell Parts: The Pallial Sinus

The pallial sinus is an etched “bent line” present on the inside of some bivalve shells, at their posterior end. The sinus is a continuation of the pallial line, a scar that indicates the limit of the bivalve body that is attached internally to its shell. The pallial sinus corresponds to a "pouch" in the animal body that houses the siphons when they are retracted. The siphons are fleshy tubes that can be expanded for the intake and outtake of water for respiration and feeding. Usually, bivalves

Shell of the Week: The Velie Marginella

Prunum succineum (Conrad 1846), reaches about 14 mm (a little more than 0.5 inch) and, like its more common relative, the Common Atlantic Marginella, Prunum apicinum, has a very glossy shell that is probably translucent in the living snail. It differs from the Common Atlantic Marginella by its slimmer shape and more pointed spire. The image includes the original label from the Brumbach collection, indicating that the shell was collected on the “shore of Pine Island Sound, Captiva Island… In dead

The Sturdy Chiton Girdle

Once again, mollusks have taken center stage in the research discipline of Biomimetics, also known as Bioinspiration. Biomimetics is a branch of engineering that derives design ideas and inspiration from special structures, materials, and substances in animals and plants. Matthews Connors of the Massachusetts Institute of Technology and his colleagues described, in a recent issue of Nature Communications, the engineering and material properties of the girdle and girdle scales in the chiton Rhiss

Shell of the Week: The Florida Lucine

Another local member of the widespread family Lucinidae, Stewartia floridana (Conrad, 1833) grows to about 28 mm (about 1.1 inch). The shell outline is circular, with a squarish, truncated posterior end. The shell surface is smooth, and the external sculpture consists of coarse, irregular growth lines. The thin, brownish periostracum (external, brownish layer) is present in well-preserved shells. Commonly found on the back-bay areas of Sanibel and Captiva. #lucinidae #floridalucine #stewartiaf

Shell of the Week: The Elusive Souverbie Lobiger

The Souverbie Lobiger, Lobiger souverbii P. Fischer, 1857, is a sea slug that reaches about 15 mm (0.6 inch) in length. Its cap-like, translucent shell (below) is very thin, covers only the central-dorsal part of the animal, and is flanked by the four parapodial lobes typical of the genus Lobiger. Most likely, the lobes act to increase the apparent size of the animal. That, combined with production of a sticky substance, probably acts to intimidate potential predators. Living Souverbie Lobigers

Zip-up That Mantle Edge!

Pen shells anchor themselves to the sandy bottom using a bundle of silky fibers called a byssus. The bivalve is buried with the shorter side of its triangular shell oriented upward, the pointy end down. The Stiff Pen Shell in the images below, Atrina rigida (Lightfoot, 1786), may be found in large quantities on the beaches of Southwest Florida during winter months, when storm waves pull the living bivalves from the bottom. The photos on the right show a living Stiff Pen Shell viewed from above.