Author Archives: José Leal

Shell of the Week: The Henderson’s Top Snail

Calliostoma hendersoni reaches 23 mm (a little less than an inch) in diameter. As with many other deep-water species of top snails (family Calliostomatidae) from the western Atlantic, this one has a very elegant shell. The base has reddish-brown spiral lines against a cream-colored background, a narrow but deep umbilicus, and the spire presents a slightly concave profile in lateral view. Most distinctively, Henderson’s Top Snail has a series of relatively large spots along the shell periphery (the outermost shell “edge”). The species lives in moderately deep water: this specimen…

Shell of the Week: The Sigsbee’s Cerithiella

Cerithiella sigsbeana is a small gastropod of the family Newtoniellidae that reaches only 13 mm (about 0.5 inch). Its elongate shell is adorned with four beaded spiral cords (“ridges”). The specimen is catalogued as Cerithiella cf. sigsbeana in the Museum collection. After a consultation with Dr Mauricio Fernandes (a marine biologist at Federal University of the State of Rio de Janeiro, Brazil, and a specialist of the Newtoniellidae), he suggested that this species could be a variation extreme of C. sigsbeana, with very pronounced beads on the spiral cord;…

A Living Colossal Squid!

Social media has been abuzz with the recent first-time confirmed observation and filming of a Colossal Squid (Mesonychoteuthis hamiltoni) at 600 m (about 1,970 feet) depth off the South Sandwich Islands, in the Southern Ocean. The observation and video were made last March 9 by scientists working aboard Schmidt Ocean Institute’s research vessel Falkor. The juvenile Colossal Squid. ©Schmidt Ocean Institute The individual squid in the video clip is a juvenile measuring only 30 cm (about 12 inches), but Colossal Squids may reach 7 meters (about 23…

Venus Clams of Southwest Florida

There are more than 20 species of Venus clams (family Veneridae) living in shallow water along the coast of Southwest Florida; here are 14 of them: 1 – Pointed Venus (Anomalocardia cuneimeris); 2 – Florida Cross-barred Venus (Chione elevata); 3 – Lady-in-waiting Venus (Chionopsis intapurpurea); 4 – Atlantic Petricolid (Choristodon robustus); 5 – Thin Cyclinella (Cyclinella tenuis); 5 – Elegant Dosinia (Dosinia concentrica); 7 – Disk Dosinia (Dosinia discus); 8 – Imperial Venus (Lirophora varicosa); 9 – Calico Clam (Megapitaria maculata); …

Shell of the Week: The Worsfold’s Wentletrap

Epitonium worsfoldi reaches 22 mm (about 0.87 inch) and is known to live in the Bahamas Islands, Cuba, Brazil, and possibly in other parts of the western Atlantic Ocean. Its stocky but elegant shell is adorned with 17–21 ribs per whorl, and there are no additional sculpture elements between successive ribs. This species was named in 1994 by Robert Robertson in what is now the National Shell Museum & Aquarium’s own malacological journal, The Nautilus. Dr Robertson, formerly a curator at the Academy of Natural Sciences of Philadelphia,…

Slipper Snails of Southwest Florida

Slipper snails (family Calyptraeidae) are often neglected by beachcombers and shell enthusiasts. Accordingly, here are the slipper snails you may find on the coast of Southwest Florida, including Sanibel and Captiva islands: 1 – Spiny Slipper Snail (Bostrycapulus aculeatus); 2 – Circular Chinese Hat (Calyptraea centralis); 3 – Black-foot Slipper Snail (Crepidula atrasolea); 4 – Depressed Slipper Snail (Crepidula depressa); 5 – Common Atlantic Slipper Snail (Crepidula fornicata); 6 – Spotted Slipper Snail (Crepidula maculosa);  7 – Little Speckled…

Hollow Alphabet Cone Shells

Our volunteer extraordinaire Dr Tom Annesley returned this week from guiding one of the National Shell Museum & Aquarium Wednesday Beach Walks with a shell fragment that he correctly identified as a portion of the spire of an Alphabet Cone (Conus spurius) shell. The fragment is 33.8 mm (1.33 inch) in its largest dimension. Conus spurius fragment found by Dr Tom Annesley Inside the fragment, one can see parts of the older whorls (red arrows) that were enveloped by subsequent shell growth. But the rests of the “walls” of…

Pyrams of Southwest Florida

Now for another episode of the “Family Pages” series of species living along the coast of Southwest Florida. This one introduces some of the micromollusks in the taxonomically challenging family Pyramidellidae. (There are additional species not yet illustrated.) Here we go: 1 – Impressed Odostome (Boonea impressa); 2 – Half-smooth Odostome (Boonea seminuda);  3 – Unidentified Chysallida species; 4 – Incised Turbonilla (Houbricka incisa); 5 – Crenulated Pyram (Longchaeus suturalis); 6 – Netted Pyram (Peristichia agria); 7 – Tower Pyram (Peristichia toreta); 8 –…

Shell of the Week: The Costate Horn Snail

Cerithideopsis costata grows to 15 mm (about 0.6 inch). The shell may have around 12 round whorls and a sculpture of low, rounded axial ribs that decrease in size in the last two whorls, The outer lip is flaring in adult shells. The color is light- to dark-brown with spiral bands of lighter color. The species thrives around mangroves and protected areas of Southwest Florida and neighboring areas. The illustration represents a shell collected in March 1963 on North Captiva Island by William C. Brumbach. Cerithideopsis costata from NOrth…

The Green Mussel Pops Up Again!

During the latest Live Mollusk Count promoted by the National Shell Museum & Aquarium on March 11, organizer and Associate Director of Education Jorden Falker found two complete shells (paired valves) of the Green Mussel (Perna viridis). The shells, found at low tide on the east end of Sanibel Island, were discovered tangled in seaweed. The hinged shell and remnants of the soft bivalves’ bodies inside hint that the mussels died recently and came from a nearby location.   Perna viridis  shells from Lighthouse Beach, Sanibel, Florida. Illustration:…