Collecting shells deriving from molluscs, terrestrial marine animals and sweet water creatures is a natural pastime on coastal areas. However, this practice on occasion develops into a passion that leads to the acquisition or study of these molluscs. A version of this hobby already had its followers in Roman times: extraordinary collections can be found, such as the one Caligula ordered as an offering to the Capitol, or the one discovered in Pompei and attributed to Pliny the Elder.

As occurred with all the major arts, shell collecting had a period of decline during the Middle Ages when the only shells that were prized were the scallops taken by pilgrims on the travels to the Holy Land or Santiago. The interest in this hobby was reawakened by the Renaissance along with the study of other sciences, such as cartography and geography, and by the great voyages of discovery of the 17th century, which led to the writing of the first shell-related books, including� Historia Conchyliorum and Recreation of the eyes and spirit in the contemplation of shells.

Respecting protected species
Collecting and acquiring these shells has now become a recognised pastime whose number of followers increases day by day. The secret of its success is that shell collecting simply requires passion and devoting time to finding shells or similar in their natural surroundings, while always respecting protected species, or else exchanging them in markets or specialised stores.

Once collected and clean, the shells must be classified using a label which lists the name, date, collector and place of collection. It is also advisable to check the authenticity of the shells, which are often altered with acids or colours.

Finally, an important thing to keep in mind before starting to collect shells is Spanish legislation, specifically fishing and seashell collecting laws which regulate the capture and possession of marine molluscs by granting commercial fishing licences for human consumption, although shells may be collected as long as they are not alive.�

Most common varieties
* Cypraea tigris: Red Sea species that in prehistoric times was associated with female fertility and the cult of the Mother God.
* Cypraea moneta: Used as coins in the time of Alexander the Great and found in the East Indies.
* Conus cedonulli: A valuable Caribbean shell, the first two known examples of which belonged to the kings of Portugal and Denmark.
* Conus gloriamaris: One of the most legendary shells. Commonly known as the snail shell, it is found in the Indian and Pacific Oceans.
* Epitonium and cowries: The epitonium found in the Caribbean and Galapagos Islands are valuable bivalve shells, as are the cowries (Cypraea fultoni).