Mollusks

The Truncatellas

The coast of Southwest Florida hosts two species of the small-sized snail genus Truncatella: The Caribbean Truncatella, Truncatella caribaeensis Reeve, 1842 (maximum size 9 mm, or slightly more than 1/3 inch), and the Beautiful Truncatella, Truncatella pulchella Pfeiffer, 1839 (maximum size 0.65 mm, or about 1/4 inch). Truncatellas derive from marine ancestors but have adapted to live almost completely independently from the marine environment, except for the moment of fertilization, when male m

The Bruised Nassa and its Egg Capsules

I last covered the Bruised Nassa, Nassarius vibex (Say, 1822), in this column on September 4, 2015. On that occasion, I mentioned that the habitats preferred by the species are the sandy-mud and mud flats of the back-bay areas that are so common in our part of the coast. I also mentioned the scavenging feeding habits of the species: Bruised Nassas are like “little vultures,” gathering in large numbers to feed on the dead bodies and remains of small marine creatures. Recently, Museum collaborator

The Pigmy Octopus

Octopuses are shell-less mollusks of the class Cephalopoda. One of the local species is the Pigmy Octopus, Octopus joubini Robson, 1929, a species rarely surpassing 5 inches in size. Given their relatively small size, Pigmy Octopuses are capable of temporarily seeking shelter inside empty shells of large gastropods (e.g., Lightning Whelks, Tulips) or bivalves (e.g., Giant Cockles, Quahogs, Pen Shells). Members of this small species, in particular females guarding their eggs, are known to inflict

The Southern Quahog, Encore

The Southern Quahog, Mercenaria campechiensis (Gmelin, 1791), is a large member of the Venus Clam family Veneridae that may grow to be more than 6 inches in size. This local species was originally covered in my column of August 22, 2014. I decided to write again about this magnificent clam after examining and taking a photo of the hinge of a very large specimen. The hinge represents the main connection between the valves, or halves, of the shell of a bivalve mollusk. It has a number of strongly

The Pitted Baby Bubble

The Pitted Baby Bubble, Japonactaeon punctostriatus (C.B. Adams, 1840), is a local microsnail that reaches about 1/5 inch in size. The shell of the living snail is transparent, becoming opaque after the animal dies, and is ornamented with spiral rows of pin-holes, which are present only on the abapical (“top”) part of the whorls. The juvenile live snail illustrated in the photo on the right was collected on September 15, 2014, by Florida Gulf Coast University (FGCU) student Thomas Behmer on from

The Atlantic Paper Mussel

A member of the Mussel family Mytilidae, the Atlantic Paper Mussel, Arcuatula papyria (Conrad, 1846), is an elusive local species that happens more abundant in nature than its relative obscurity and scarcity in local collections would lead us to believe. One of the reasons for its status as a poorly known species is that it lives burrowing in the muddy bottoms of local bays and protected back waters, in areas that are difficult to reach and almost impossible to walk on due to the plastic, very s

The Banded Tulip

The Banded Tulip, Cinctura hunteria (G. Perry, 1811), is one of the largest and most attractive marine snails found along the barrier islands of Southwest Florida. The species, which may reach in excess of 4 inches in size, is also present in other parts of the Gulf of Mexico, eastern Florida, and northern Caribbean Sea. The smooth, tulip-shaped shell is characterized by the widely spaced, brownish spiral lines set against a light gray background color. The species is related to the True Tulip,

The Ponderous Ark

The Ponderous Ark, Eontia ponderosa (Say, 1822), is one of the most common shells found on the beaches of Sanibel and Captiva islands. One of the most striking features of this species is its dark-brown or black, velvet-like periostracum, the organic shell layer that covers part or the entire shell. Visiting beachgoers often confuse the periostracum of the Ponderous Ark for a layer of oil or tar that could have deposited on the white shell. Another feature that sets the Ponderous Ark apart from

The Tiny Dwarf Olive

The Tiny Dwarf Olive, Olivella pusilla (Marrat, 1871), is a local species found in relative abundance on sandy-mud bottoms and mud flats. Dwarf Olives used to be united with “normal-size” Olives in the family Olividae, but details of the anatomy and DNA separate them into their own family, the Olivellidae. The shell is up to 8 mm (about ¼ inch) in size, bullet-shaped, with about 5 whorls, and short spire. The color pattern in this species is very variable, but usually includes a cream, grayish,

The Pitted Murex

The Pitted Murex, Favartia cellulosa (Conrad, 1846), is one of the less-known Murex drills in Southwest Florida. Its shell may be pure white or whitish with brown undertones. The Pitted Murex derives its name from its shell sculpture. The shell surface is sculpted with apparent small pits, which closer inspection reveals to consist of a lace-like, interwoven pattern. One of the features of the shell in this species is the presence of varices, the wing-like expansions that repeat themselves at re