See text The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda.

This family is commonly known as the top-snails because in many species the shell resembles a toy spinning top.

This goes from low auriform (ear-shaped) with a wide aperture to the long, slender conical forms of typical top shells.

They have a brown, entirely corneous, circular, multispiral operculum which fits the aperture snugly.

[3] Species of the family Trochidae are dioecious, and the fertilization occurs externally by the release of eggs and sperm.

Individuals may hatch as free-swimming planktonic larvae or juvenile crawlers with a short swimming stage.

[3] This family of snails consists of herbivores, grazing with their radulae on rocky surfaces, feeding on algae and vegetable detritus, and more rarely by filter-feeding, as observed in the genus Umbonium.