Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With about 1,600 living species, the Muricidae represent almost 10% of the Neogastropoda. Additionally, 1,200 fossil species have been recognized.
Numerous subfamilies are recognized, although experts disagree about the subfamily divisions and the definitions of the genera. Many muricids have unusual shells which are considered attractive by shell collectors and by interior designers. Periostracum is absent in this family.
Most species of muricids are carnivorous, active predators that feed on other gastropods, bivalves, and barnacles. The access to the soft parts of the prey is typically obtained by boring a hole through the shell by means of a softening secretion and the scraping action of the radula. Because of their carnivory, some species may be considered pests because they can cause considerable destruction both in exploited natural beds of bivalves, and in farmed areas of commercial bivalves.
Muricids lay eggs in protective, corneous capsules, the size and shape of which vary by species. From these capsules the crawling juveniles, or more rarely planktonic larvae, hatch.
Members of the genus were harvested by early Mediterranean peoples, with the Phoenicians possibly the first to do so, to extract an expensive, vivid, stable dye known as Tyrian purple, imperial purple, or royal purple, namely Bolinus brandaris (Purple dye Murex). Many species are also eaten. In this sub-family, most of the larger and well known species resides.