Author Archives: José H. Leal

Cowries are Cool!

Throughout human history, the enjoyment of shells and curiosity they spark have been the foundation for the science and better understanding of mollusks. And no other group of shells evokes more interest and appreciation than cowries (family Cypraeidae). Their “egg-shaped” shells are usually smooth, glossy, and their weight “feels” just right when held in one's hand. From time to time the living snail covers the shell from both sides of a slit-like opening, and the shell-making mantle repairs bl

Metamorphosis in a Sea Snail

In a way that is analogous to what happens when a caterpillar becomes a butterfly, the change in lifestyle from a pelagic (open-water dweller) larva to a bottom-living adult is also known as metamorphosis. The illustration presents three shell-growth stages of an Atlantic Gray Cowrie, Luria cinerea (Gmelin, 1791). From left: the planktonic (free-living) larval shell; juvenile shell briefly after settlement to the bottom-living stage; and adult shell. They are all so different, yet all are stages

Upside-down Baby!

In gastropod mollusks, the larval shell ("baby" shell, or protoconch), is usually retained in the apex (the "tip") of the adult shell. After metamorphosis from larva to adult, there may be differences in color, thickness, and texture between the protoconch and the adult shell, but usually the direction of coiling stays the same with growth. Gastropods with a right-handed larval shell continue to grow a right-handed adult shell, and vice versa.An exception to this same‐coiling-direction "rule" is

Shell of the Week: The Brown-tip Mangelia

Kurtziella atrostyla (Tryon, 1884) is a relatively common gastropod along both coasts of Florida. Its elongate shell may have up to 7–8 whorls, reaches only about 9 mm (about 0.36 inch), and is decorated with 8–10 axial (lengthwise) ribs and fine spiral (“across-shell”) striations. The shell is white, with reddish-brown suture (area where two whorls join) and inner part of the aperture (“opening”). #kurtziellaatrostyla #mangeliidae #spiral #axial #mageliidae

A Cool Deep-sea Octopus!

Social media was abuzz recently with this image of a beautiful deep-sea octopus photographed at 1,177 m depth by the crew of R/V Falkor of the Schmidt Ocean Institute, during their recent Visioning Coral Sea expedition off Australia. Michael Vecchione, Curator of Cephalopoda at the Smithsonian, identified it as a species of the genus Muusoctopus. I wrote about another species of Muusoctopus in the November 29, 2019 issue of this blog, briefly describing the "Octopus Garden." This is a large, imp

Shell of the Week: The Wide-coil Wentletrap

Today, I want to introduce the last species of our three-part series on open-coiling, the Wide-coil Wentletrap, Cycloscala echinaticosta (d’Orbigny, 1842), a species found in the tropical western Atlantic Ocean. In this species, the degree of coiling “openness,” or the distance from one whorl to the next, can vary wildly among individual shells. The possible advantages for these species to "wear" open-coiled shells have not yet been fully explored by malacologists. #widecoilwentletrap #cycloscal

Snakes and Snail “Handedness”

As discussed previously in this blog, most snail species coil to the right (dextral), and a few, such as the local Lightning Whelk, coil to the left (sinistral). In a few species of land snails, however, there seems to be as many dextral individuals as there are sinistral ones. Switch gears to snail-eating snakes: As their common name suggests, Southeast Asian snail-eating snakes in the genus Pareas evolved to prey on snails, and do it by initially biting onto the outer rim (the “outer lip”) of

Nature’s Iron-based Shell Dye

Did you ever wonder why some shells on the beach are abnormally dark-gray, bluish, or almost black? They are not dark to begin with: The right valve of a Southern Quahog, Mercenaria campechiensis, on left, acquired its dark, bluish hues after being buried in sand or mud for some time (compare to “normal” color valve on right.) In sand or mud with levels of oxygen below normal (hypoxia) or where oxygen is completely lacking (anoxia), trace amounts of iron in the shell will combine with sulfur to

Shell of the Week: The Miller Nutmeg

Last week, using the Exquisite False Dial as an example, I introduced open-coiling, a situation where successive shell whorls do not touch each other, each whorl maintaining regular, proportional distances from its neighboring whorls. Other gastropods with open-coiling are, for instance, some members of the nutmeg family Cancellariidae, such as Extractrix milleri (Burch, 1949), from the eastern Pacific Ocean including the Galápagos Islands (below), an attractive gastropod related to our Common N

Shell of the Week: The Exquisite False Dial

Spirolaxis centrifuga (Monterosato, 1890) is a delicate and truly attractive species of the sundial snail family Architectonicidae. The species is found in deeper water in the western and eastern Atlantic, and may grow to about 5 mm (0.2 inch) in diameter. The shell is open-coiled, with successive whorls (shell “turns”) not touching each other, yet maintaining regular, proportional distances from the neighboring whorls. Gastropods from other families make open-coiled shells; they are all very el