Lightning Whelk, Sinistrofulgur perversum
Lightning Whelk Shell, Sinistrofulgur perversum. Shell collected from coastal waters of Akumal, Quintana Roo, October, 2005. Length: 4.2 cm (1.6 inches). Width: 3.1 cm (1.2 inches). Collection, photographs, and identification courtesy of Bob Hillis, Ivins Utah.
Phylogeny: The Lightning Whelk Shell, Sinistrofulgur perversum (Linnaeus, 1758), is a gastropod member of the Busyconidae Family of Busyconidae Whelks. This family is endemic to the east coast of North America. The genus Sinistrofulgur is one of six genera in the family, and there are four species in this genus. They are also known as the Perverse Whelk. The family name Busyconidae comes from the Greek, meaning ” large fig”, referring to the general shape of the shell. The Sinistro portion of the genus refers to the Latin word sinister, meaning “left-handed”. When these shells held with the spire pointing up, and the aperture facing you, the aperture is on your left side. This is the opposite of most gastropods, which are dextral, or right-handed. The specific name perversum comes from the Latin, meaning “turned the wrong way.” Other species in this genus share the common name Lightning Whelk.
Description: Lightning Whelks are large, cone-shaped shells, consisting of four or five whorls. The margins of the whorls are sculpted by small nodes, though the last whorl may display larger spines. The spire is low and pointed. The body whorl is elongate and sculpted with weak spiral ridges. The aperture is oval-shaped, and the anterior canal is long and open. When viewed from above, this shell spirals counter-clockwise. The exterior may be white, tan, or gray, with brown lines (lightning bolts) running the length of the shell. The interior is white. The living animal is dark brown or black. Lightning Whelks reach a maximum of 40 cm (16 inches) in length.
Habitat and Distribution: Lightning Whelks are found in protected waters, on sand or mud substrates, often near shoalgrass or turtlegrass beds within the intertidal zone, and to depths up to 45 m (150 feet). They are a temperate to tropical Western Atlantic species that in Mexican waters are found throughout the Gulf of Mexico to, at least, the tip of the Yucatan Peninsula. Some sources extend this range to Belize.
Ecology and Behavior: Lightning Whelks are predators that feed primarily on bivalves, including oysters, clams, and scallops. In turn they are preyed upon by shore birds, crabs, gastropods, and fish. They are gonochoric and reproduce sexually, with indirect fertilization. The eggs are laid in long strings of protective capsules. Any form of commensal, parasitic, or symbiotic relationships has not been documented, although their empty shells are often used by hermit crabs for housing. They are edible and a target of artisanal fisheries. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.
Synonyms: Busycon (Sinistrofulgur) perversum, Busycon perversum, Busycon perversum perversum, Fulgur gibbosum, Fulgur perversum, Murex perversus, and Pyrula kieneri.