Spindle Tibia Shell – Tibia Fusus (Strombidae)
Approximate Size: Length 8.5″, Height 1.5″, Depth 1.5″
Tibia Shells belong to the family Strombidae. They are considered one of the true conch shells. Tibia’s are spindle shaped with a long siphonal canal. These are a colour group and some species are highly prized by collectors. Most live in off shore waters where there is plenty of sand.
Genus Tibia (The Macdonald Encyclopedia of Shells)
Medium or Large size (1 to 12 inches), very high conical spire (turreted), the whorls are markedly convex, impressed suture. Slightly expanded aperture lips, bordered by an external swelling, always smooth; there are usually fingers, sometimes rather long, on the outer lip. The columellar lip has a callus, which is sometimes very thick. There is always a sharp anterior canal; in Tibia Fusus it is as long as the rest of the shell. At the point of attachment of the aperture to the body whorl there is always a notch or even a posterior canal. The sculpture is generally more marked on the first whorls, where it consists of axial ribs that cross fairly prominent spiral furrows. The other whorls are finely scored by very thin spiral grooves, which are generally more obvious on the base of the body whorl. The colour varies from yellowish to quite dark chestnut; some species also have darker or lighter spiral stripes or bands. The operculum is horny, ovoidal, slightly arched, with an apical nucleus.
An elongated curved foot, the posterior more developed and producing the operculum. The mantle margin is digitate. The head is distinct and has two long, thick ocular peduncles, the tentacles are fused to these and project from the top of them. The mantle cavity contains a gill, an osphradium and, in males, a penis.