[1] When the word "trochus" or "Trochus" is used in reference to fishing sea snails for commercial purposes, the usual species targeted is Tectus niloticus, which is valued for its nacre or mother of pearl layer, which was traditionally made into items such as pearl buttons and jewelry.
The name Trochus, according to P. Fischer[2] was used for the first time by Guillaume Rondelet, in 1558, who assembled under this title a rather miscellaneous assortment of univalves.
Linnaeus' genus Trochus is composed principally of true Trochidae, but it is now viewed as having contained species of several other very different families.
Sea snails in the genus Trochus have large, thick, solid shells that have a broadly conical spire and a flat to convex base.
[3] The interior of the shell is pearly and iridescent because of a thick layer of nacre (mother of pearl).