Nobel Top Shells of the Calliostomatidae Family

Four Nobel Top Shells of the Calliostomatidae Family can be found in this website:

Phylogeny: Nobel Top Shells of the Calliostomatidae Family are gastropod mollusks in the Trochida order. The Trochoidea superfamily is the only superfamily in this order. The family Calliostomatidae is one of thirteen families in the Trochoidea superfamily. The Calliostomatidae Family is large and is comprised of six subfamilies, thirty-one genera and around six hundred sixteen species. The genus Calliostoma is by far the largest genus in this family, with three hundred eighty-four species. Until fairly recently the Calliostomatidae Family was considered to be a subfamily of the Trochidae Family.  Shells in the Calliostomatidae Family are also commonly called Calliostomatids.

Description: Nobel Top Shells are conical shells that are comprised of several flat-sided or rounded whorls. The apex is generally fairly pointy. Their exterior may be smooth or sculpted with spiral cords that are beaded, knobbed or smooth.  Shells in this family come in a variety of colors and color patterns. The interior is nacreous.  Living specimens have a round, multi-spiral, operculum. The largest species in this family reaches 10 cm (3.9 inches) in length.

Habitat and Distribution: Noble Top Shells are generally found on hard substrates but some species are found attached to plants or on soft substrates. They live in the intertidal zone, and to depths of, at least, 1,247 m (4,090 feet), though some sources extend the maximum depth to over 3,000 m (9,840 feet). Noble Top Shells are found in tropical to polar seas. Fifteen species from the Calliostomatidae Family are found in Mexican waters.

Natural History: Noble Top Shells may be herbivores, omnivores, carnivores, or detritivores. They feed on detritus, algae, diatoms, carrion, hydroids, bryozoans, and sponges. In turn they are preyed upon by shorebirds, crabs, fish, gastropods, and octopuses. Noble Top Shells differ in their mode of reproduction from most other top shells. Most top shells cast their gametes into the water column where fertilization takes place and the resulting veliger larvae drift as plankton before settling to the bottom as snails. Noble Top Snails lay their eggs in a gelatinous ribbon which are then fertilized. They bypass the planktonic stage, and develop directly into snails. The name Calliostoma comes from the Greek words for “beautiful mouth”, referring to the iridescent aperture.