Top Shells of Tegulidae Family
Five Top Shells of the Tegulidae Family can be found in this website:
Phylogeny: Top Shells of the Tegulidae Family are members of the Trochida order. The superfamily Trochoidea is the only superfamily in this order. The family Tegulidae is one of thirteen families in the Trochoidea superfamily. The Tegulidae Family is moderate in size, with no subfamilies, eight genera and around seventy species. Shells in this family are also commonly called Tegula Top Shells or Tegulids. For many years this family was considered to be a subfamily (Tegulinae) within the Turbinidae Family. Description: Top Shells in this family are solidly built and range from small to large in size. They may have a globose snail shape or be more conical. The whorls may be angular, rounded, or straight-sided. The exterior surface of the shells may be smooth or sculpted with knobs, spiral lines or axial ridges. The circular base usually displays spiral ridges. These shells tend to be drably colored, but sometimes display beautiful patterns. The aperture is round and the outer lip is smooth. The columella has one or more teeth. The interior is nacreous. The operculum is corneous (a material similar to cow horn). The largest species in this family reach 10 cm (3.9 inches) in length. Habitat and Distribution: Tegula Top Snails are found on hard substrates or attached to plants. They live in the intertidal zone and to depths exceeding 100 m (328 feet). They are found worldwide in tropical to temperate seas. Fourteen species from the Tegulidaer Family are found in Mexican waters. Natural History: Tegula Top Shells are herbivorous grazers that feed on algae. In turn they are preyed upon shorebirds, crabs, fish, and carnivorous mollusks. These shells are gonochoric and reproduce sexually through broadcast spawning, with external fertilization. Top Shells are edible and larger species are harvested by artisanal fisheries.
Norris Top Shell, Norrisia norrisii
West Indian Top Shell, Cittarium pica
