Everybody Loves Seashells – If you have ever walked the beaches along the Atlantic or Pacific coasts, you have likely come across various seashells, lovely and irresistible to pick up! Follow along for interesting facts and identification guidlines for those seashells that filled you with wonder!

The univalve seashells profiled in this photo essay can be found in the subtropical to tropical Atlantic coastal regions bordering the USA, the Caribbean, South America and the Gulf of Mexico or the Indo-Pacific coastal regions bordering India, China, Japan, Australia, Indonesia, South Korea, Russia and the USA.  

What Is a Univalve? Univalves, otherwise known as gastropods or snails (sea snails), possess valves (shells) characterized by a single shell, typically spiraled.  When identifying univalve shells, location is important along with the obvious features such as shape, textures, markings, and color. Size is important as well, but keep in mind that sometimes you may have found a juvenile that hasn’t reached full size.

Univalve Identification and Facts in the following order:

• 1. Pearl Top
• 2. Jujube Top
• 3. Alphabet Cone
• 4. Nutmeg Sea Snail
• 5. Arabic Cowrie
• 6. Snakehead Cowrie
• 7. Purple Top Tiger Cowrie
• 8. Wandering Cowrie
• 9. Atlantic Bubble Snail
• 10. Moon Shark Eye
• 11. Atlantic Common Slipper
• 12. Letter Olive
• 13. Olive Sea Snail

1. Pearl “Trochus” Top Sea Snail (Trochus lumea)

The Pearl Top shell displays cream colored stunning iridescence, prized for their mother of pearl glow. The shell is thick, conical in shape with a sharp spire displaying 8 to 10 whorls. The base is flat showing numerous circular ridges.

• Crafted into jewelry making, buttons, beads, and even crushed for countertops and flooring.
• Another favorite in gift shops of Florida and other Atlantic Coast or Indo-Pacific tourist cities around the world.
• Size: Up to 2.5 in, 6 cm
• Habitat: Typically in shallow, rocky, or coral-rich areas in depths ranging from 0 to 65 feet (0 to 20) meters, with juveniles preferring shallow intertidal reef flats for protection and food, while adults migrate to deeper, more exposed slopes. They graze on algae, requiring clean water with high calcium levels. 
• Range: Indo-Pacific region

Jujube Top Seashells

2. Jujube Top Sea Snail (Calliostoma jujubinum)

The Jujube Top sea snail displays a pyramid cone-shaped shell that can vary color-wise from chestnut-brown, purple-brown, green-gray, or tan mottled. It is marked with narrow, curved, widely separated longitudinal white elevated streaks. In addition, finely beaded ribs decorate the surface. It has about 10 whorls on the way up to a pointy spire. The base is flattened with an iridescent white interior.

• Size: Up to 1 1/4 in, 3 cm
• Habitat: Shallow to deeper waters, ranging from 0 to 625 feet (0 to 192 meters) in depth. These snails live on rocky surfaces, corals, and seaweeds. 
• Range: North Carolina south to Florida, Bahamas, West Indies, and further south to Brazil; also west to the Gulf of Mexico coast

3. Alphabet Cone Sea Snail (Conus spurius)

The Alphabet Cone possesses a medium-size cone shaped shell. The opening lip is narrow and extends the length of the outer shell. They are colored creamy-white decorated with rows of reddish brown splotches, some resembling letters of the alphabet. The top of the cone or spire has a small pointy apex.

• All cone snail stings are toxic; always use caution when collecting their shells. They are nocturnal hunters that use a venomous, harpoon-like tooth to catch prey.
• Size: Up to 3 in, 8 cm
• Habitat: Sandbars and grassy flats in shallow water and near coral reefs or hiding in rocky rubble at depths from 0 to 200 feet (0 to 64 meters). 
• Range: North Carolina to Florida, the Caribbean and Gulf of Mexico

4. Nutmeg Snail (Cancellaria reticulate)

The Nutmeg Snail shell is small and resembles the shape of a nutmeg seed with the same roughness and texture, hence the name. The background is white with various shades of brown arranged in spiral beaded bands and longitudinal stripes. The apex displays several whorls coming to a point. Nutmeg snails are marine gastropods that uses a long, tubular snout to extract bodily fluids and soft tissues from other marine animals. 

• Size: Up to 1 3/4 in, 3 cm
• Habitat: Grassy shallow bottoms or kelp beds; sand or mud substrates in the intertidal zone and extending down deep offshore depths to 9000 feet (3000 meters).
• Range: Worldwide; North Carolina to Florida southern tip to Brazil, and Indo-Pacific regions. 

5. Arabic Cowrie (Cypraea arabica)

The Arabic Cowrie is named for the shell’s irregular patterns of thin longitudinal brown lines that are sometimes interrupted by empty spaces, giving an appearance considered similar to Arabic script. As with most cowrie snails, the Arabic Cowrie shell surface is notably shiny, as if it had been polished. The color is generally cream with shades of brown and blue-gray streaks or spots. The underside is cream to grey colored. Both the inner and outer lips are lined with arrays of small reddish-brown teeth bordered by dark speckles or spots.

• The Arabic Cowrie hides during the day, becoming active at night to feed. Using a specialized, rasp-like tongue called a radula, it consumes encrusting sponges, bryozoans, and, in captivity, is known to graze on nuisance hair algae. 

• Size: Up to 2.5 in, 6.5 cm
• Habitat: Shallow water under rock rubble and crevices or  in coral reef outskirts typically from the low intertidal zone to depths from 30 to 130 feet (10–40 meters)
• Range: Widespread in the Indo-Pacific region, including East and South Africa, reaching Polynesia and Japan.
• Additional Facts About Cowries
• In some cultures, cowrie shells are a symbol of fertility and are often offered to a bride as a gift to ensure fertility.
• Cowries egg-shaped, glossy shells are in high demand for rock aquariums.
• They differ in color depending upon geographical location.
• While the cowries do not have an operculum to shut when it retracts its mantle into its shell, the opening is lined with “threatening” tooth-like structures.

6. Snakehead Cowrie (Cypraea caputserpentis)

The Snakehead Cowrie shell, as with other cowries, is oval-shaped, with a raised central area. Its top is olive-brown with irregular spots of white, blue-gray, or cream-colored. A faintly frilled brown band runs along the base of the shell, and a white line or mantle line runs from front to back along the shell top; displays a glossy finish.

• Size: quite small – 1 1/2 in, 3 cm
• Habitat: Shallow turbulent water under loose rock or along shorelines and seawall cracks, typically in depths from 3 to 10 feet  (1–3 meters), but can be found down to 700 feet (200 meters). They hide under boulders and in crevices during the day to avoid predators emerging at night to graze on algae. 
• Range: Indo-Pacific region from eastern African coasts. Also, the Hawaiian coasts. The Hawaiian name is “leho-kupa”. It is the most common species in the Hawaiian Island chain.

7. Purple Top Tiger Cowrie (Cypraea tigris)

The Purple Top Tiger Cowrie is also commonly known as the Tiger Cowrie. This marine gastropod displays an egg-shaped shell, typically 2 to 3+ inches long, featuring a high-gloss and a white-to-buff base partially covered in dark brown or black spots. The distinctive “purple top” is achieved by polishing or buffing the dorsal layer to reveal a purplish hue, often used in coastal decor, crafts, and jewelry; is used in carvings such as cameos due to this uniform color under the top layer.

A cowrie shell turns dull primarily due to the loss of its natual protective glossy layer, often caused by environmental factors, age, or improper handling after it is removed from the ocean. While living, the cowrie’s mantle covers the shell to keep it shiny. 

• When small, they eat algae and scavenge for scraps, as adults, they eat anemones, sponges, and soft corals polyps.
• Size: Up to 6 in, 15 cm
• Habitat: Shallow water under coral or rocks typically found at depths of 30 to 130 feet (10 to 40 meters), often on live coral colonies (especially Acropora) or on sandy, rocky bottoms near reefs. 
• Range: Indo-Pacific and the Great Barrier Reef in Australia, also ranging from the eastern coast of Africa to Hawaii.

8. Wandering Cowrie (Erronea errones)

The Wandering Cowrie possesses an oval shell typically displaying colors of pale blue, or greenish with variable darker bands of brown or small spots. The base of the aperture is white and extends upwards along the sides. The anterior end tilts right.

• Feeds at night on sponges, algae, and encrusting organisms.
• Size: Small, up to 1.8 in, 20 cm
• Habitat: Shallow tropical waters at low tide intertidal rocky shores, coral reefs, and areas with coral rubble. They are often found hiding under rocks, stones, or among sponges during the day to avoid predators. 
• Range: Indo-Pacific region: East Indian Ocean along south India, Madagascar, and Tanzania, west along Indonesia, Malaysia, Philippines, Samoa, and Australia

9. Atlantic Bubble Sea Snail (Bulla striata)

The Atlantic Bubble shell is barrel-shaped, displays light brown spots with many light and dark flecks, and has a white opening. The shell is smaller than the animal, loosely curved, thin, and brittle.

• Atlantic Bubble Sea Snails are not true snails because they are essentially a transitional form between snails and sea slugs, characterized by a fragile, small, often internal shell that cannot fully protect their body. 
• Size: Small, up to 1 in, 2.5 cm
• Habitat: Shallow, calm warm water, sheltered mudflats, and seagrass beds burrowing at night.
• Range: North Carolina to Florida, west to the Texas Gulf Coast, south to Brazil

10. Moon Shell Shark Eye (Polinices duplicata)

The Moon Shark Eye shells vary in colors from slate-gray to tan or pinkish, blended with creamy-white. The interior is chestnut colored. The shell is smooth and rounded, flatter than other Moon Shells. The underside has a button-like brown callus in the center.

• The Moon Shark Eye shells are considered valuable to collectors.
• Moon snails include about a dozen widely distributed species. Their shells are found on all U.S. Atlantic and Pacific beaches. These carnivores feed on other shellfish, which they engulf and smother with the aid of an usually large foot.
• Moon Shells build a circular “sand collar,” cementing the sand grains with a glue they produce, then deposit their eggs inside the protective ring.
• Size: Average 1 in, 2.5 cm, but can grow up to 3 in, 7.5 cm
• Habitat: Sand bars, intertidal and shallow subtidal zones, often burrowing just below the surface in sandy shores and surf zones. 
• Range: Canada to Florida, west to the Gulf Coast, south to Brazil

11. Atlantic Common Slipper (Crepidula fornicate) 

Atlantic Common Slipper sea snail shells display a creamy white background and curved chestnut-colored stripes variously placed. The inside is shiny and sometimes colored brown. The shell is thin and translucent, with an oval or boat shape. There is a shelf or “seat” in the hinge end, which resembles the stern seats on a boat or put all together, a slipper.

• The Slipper Sea Snail can change sex and it is interesting to note that in a large group, they stack atop one another; the top layers will be male, the bottom layers female and the section in the middle will be neuter in the process of changing male to female.
• The Atlantic Sipper is also known as Baby’s Cradle, Boat Shell, Slipper Limpet, Canoe Shell, or Common Slipper.
• They are edible.

• Size: Up to 3 in, 7.6 cm
• Habitat: Shallow muddy bottoms piled in groups of larger empty shells; lower intertidal and shallow subtidal marine waters, favoring sheltered areas like bays and estuaries. They attach to hard substrates such as rocks, shells, dock pilings, and ship hulls; they thrive in temperatures ranging from cold to subtropical. 
• Range: Native from Northwest Atlantic Newfoundland Canada to Florida and west to Texas to Gulf of Mexico and introduced to the Northeast Pacific, Europe (Norway to Spain), and the Mediterranean.

12. Lettered Olive (Oliva sayana)

The Lettered Olive sea snail shell is cyndrical, oblong, colored light brown with an overlay of darker brown that resembles lettering and has a glossy finish.

• This sea animal is almost always found alive, recognized by a burrowing ridge in the sand at low tide, somewhat resembling a mole in a field.
• They usually live in colonies.
• They are non-edible.
• The shells have a beautiful polished appearance when cleaned properly.
• Size: Up to 2 1/2 in (6 cm) to 3 1/2 in (9 cm)
• Habitat: Shallow sandy bottom, near-shore inlets and sandbars from intertidal and subtidal zones, typically to 10 feet (6 meters) deep where they spend most of their time burrowing just beneath the surface of the sand in search of bivalves. 
• Range: North Carolina to the Gulf Coast to Brazil, particularly the Florida Gulf Coast. Largest colonies have been located around Sarasota Bay and near the Gulf passes.

13. Olive Sea Snail

The family of Olive Sea Snails display shells that are typically smooth and shiny, except the one in my collection reveals thin brown groves over the exterior. The shells are typically bullet shaped coming to an apex point with three to five wide whorls. The bottom twists in my sample. The Olive Sea Snail family is large with many tropical species. Though, I am baffled about the specific species, it could be the purple olive sea snail (Callianax biplicata). While those are named for their frequent purple or violet tint, they are highly variable in color and can appear in shades of tan, grey, white, or light brown. 

• Olives are fast-moving, carnivorous, and use a long siphon as a snorkel while submerged. 
• Size: From 1 to 3.5 in (9 cm)
• Habitat: Shallow topical to subtropical sandy intertidal zones, burrowing for safety using a large muscular foot. They are active burrowers that prefer sandy beaches, inlets, and areas near coral reefs, often found at depths down to 20 feet (6 meters) 
• Range: Foundacross the Atlantic Coasts including the Caribbean and Brazil, the Gulf of Mexico, and the Pacific Coasts. 

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