Mollusks

The Turkey Wing and Mossy Ark

This is the tale of two sister species: one gets all the glory, and the other goes "mossly" unnoticed. But these two species are actually very similar and easy to confuse. The Turkey Wing (Arca zebra) has a shell coloration that resembles the color pattern on the wings of a Wild Turkey (and the shell outline evokes the wing's shape). The Mossy Ark (Arca imbricata) lacks that strong color contrast and the well-defined pattern present on the Turkey Wing. This latter species shows a long projectio

The Minor Jacknife

The Minor Jacknife (Ensis megistus Pilsbry and McGinty, 1943) has a very delicate, elongate shell with an unusual coloration that includes purplish vertical bars internally. It is a burrower, living in fine sand and mud. Minor Jacknives inhabit and can move up and down vertical or oblique, cylindrical burrows. A Minor Jacknife can burrow rapidly by using its foot as a piston inside their dwelling. In some extreme cases, individuals are known to leap out of burrows to evade predators. The Mino

The Imperial Venus

Local beach renourishment episodes are known to contribute different or unusual species to the normal local diversity. As sand is pumped from offshore sites, deeper-water species are also “sucked” by the dredges and deposited on the newly formed beach. Last year’s beach enhancement on Captiva contributed several unusual species, including this Imperial Venus (Lirophora latilirata (Conrad, 1841)) valve found by Kimberly Nealon on Easter Sunday on the beach around the middle of the island. Imperia

The Pointed Venus

The Pointed Venus, Anomalocardia cuneimeris (Conrad, 1846), is found occasionally on the island beaches. It belongs to the large Venus Clam family, the Veneridae, which also includes better known local species such as the Southern Quahog (Mercenaria campechiensis) and the Sunray Venus (Macrocallista nimbosa). Perhaps because of its small size (never larger than one-inch long) or delicate colors, the Pointed Venus doesn’t strike a note with casual collectors. I find the shell elegant, however, wi

The Tinted Cantharus

The Tinted Cantharus (Gemophos tinctus (Conrad, 1846) is a relatively common gastropod around the islands, where is found living mostly on Oyster reefs. The shell is thick and heavy for its size, with a reticulated (“criss-crossed”) sculpture and color pattern of varied shades of brown and reddish brown. The egg cases are spherical, depressed in the center, and are attached to hard surfaces by a round base. The Tinted Cantharus, Gemophos tinctus, from Sanibel. The photos of egg cases were taken

The White-crested Tellin

The White-crested Tellin, Tellidora cristata (Récluz, 1842) is an uncommon local clam that stands out thanks to its extremely thin, almost flat shell. An inch-long White-crested Tellin is only 1/8" thick! (A shape-related analogy for those of you into fishing: a White-crested Tellin is to other Tellins what a Lookdown is to a Pompano or a Jack.) This clam, always white, sometimes bears a set of tooth-like projections in front and back of the shell “beak.” Paired valves are not easy to come by,

The Trapped Sunray Venus, or a Meal Gone Wrong!

This Nine-armed Sea star (Luidia senegalensis) "choked for life" on the shell of a Sunray Venus (Macrocallista nimbosa). Many species of Sea Stars are known to feed on clams; the Sea Star distends the end of its gut to feed on the mollusk, and sometimes the shell gets stuck in the process. The Sea Star was able to continue living, growing "around" the shell. The Sea Star was found by Museum friend Regina Salis (Rochester, NY) during the first week of March 2014, on Sanibel. Two views of the Nin

The Red-brown Ark

The Red-brown Ark, Barbatia cancellaria (Lamarck, 1819), is a relative of the famous Turkey Wing. The species lives offshore in the Gulf of Mexico, attached by a bundle of fibers (called byssus) to the underside of rocks and coral ledges. Valves of the Red-brown Ark have been found recently on Captiva and the Blind Pass area, where they have been found in sand deposited by the recent beach renourishment project. The shell in the illustration was found by Karla Mason of Grand Blanc, Michigan, on

The Transverse Ark

The Transverse Ark, Anadara transversa (Say, 1822), reaches 1.5 inches in size, and is seldom found in pairs. The species may be considered as the “ugly duckling” among the Sanibel shells: often neglected by collectors, it is the most common shell found in our beaches, according to an article published in 2012 by citizen scientist Susan Hewitt from New York, NY, in the magazine “The Festivus.” The Transverse Ark, Anadara transversa, from Sanibel. Photo by José H. Leal. #TransverseArk #Anadara

The Ribbed Cantharus

The Ribbed Cantharus, Hesperisternia multangula (Philippi, 1848), is a very variable species ranging in color from brown-marked to orange shells. The Ribbed Cantharus closely resembles two species of oyster drills, the Mauve-mouth Drill and the Gulf Oyster Drill, and for this reason is also known as the False Drill. The Ribbed Cantharus has eye-catching egg cases that resemble miniature stars. The Ribbed Cantharus, Hesperisternia multangula, and its egg cases. #Hesperisterniamultangula #Rib