Purpurellus pinniger is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

, a marine gastropod mollusk in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Muricidae

Muricidae

Muricidae, common name murex snails or rock snails, is a large and varied taxonomic family of small to large predatory sea snails. With approximately 1,600 living species the Muricidae represent almost 10% of the Neogastropoda. Additionally, 1,200 fossil species have been recognised...

, the murex snails or rock snails.

Description

The shell is bright white and glossy with irregular bands of brown. There are three strong varices bearing an irregular fluted or wavy edge, and a sharply incurved spine on the varix of later whorls. The early whorls can appear translucent and show a brownish blue color beneath. The varix on the outer lip ends well above the siphonal canal, which is curved, and ends in a wavy flattened edge similar to the varices in shape. The aperture is subovate and the operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

 is dark brown. Length 50 mm, width 25 mm.

Distribution

Found subtidally along the coast of Central America

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 from San Marcos Island and Guaymas

Guaymas

Guaymas is a city and municipality located in the southwest part of the state of Sonora in northwestern Mexico. The city is located 117 km south of the state capital of Hermosillo, and 242 miles from the U.S. border, and is the principal port for the state. The municipality is located in the...

 to Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

in water as deep as 82 m.