Calliostomatidae

Calliostomatidae is a family of marine gastropod mollusks in the superfamily Trochoidea. Members of this family are commonly referred to as calliostome top snails. They have a cosmopolitan distribution, inhabiting a range of marine environments from shallow subtidal zones to deep waters, on rocky substrates, coral reefs, and similar hard bottoms.

Shells in Calliostomatidae are typically conical to turreted, often with a pronounced spire and a rounded body whorl. They are usually sculptured with spiral cords, beads, or raised ridges and may display bright colors or banding. The interior of the shell is often nacreous (mother-of-pearl). The operculum is calcareous and concentric, and the presence and form of the umbilicus vary by species, being open in some and closed in others.

Ecology and biology: most species are grazers, feeding on biofilms and microalgae on rocks and other hard substrates. They occupy a variety of depths and are typically detritus or algae-rich components of benthic communities. Reproduction is generally sexual, with many species releasing eggs and sperm into the water column; larvae are often free-swimming veligers before settling as juveniles.

Taxonomy and systematics: Calliostomatidae has been treated as a distinct family within Trochoidea, though historical classifications placed related genera in Trochidae. The family’s composition includes the type genus Calliostoma and numerous other genera; molecular data have informed ongoing revisions of genus-level relationships within the group.

Selected genera: the type genus is Calliostoma; the family comprises multiple additional genera, reflecting its diversity across marine environments.