Mercenaria is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of edible saltwater clams, marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 bivalve molluscs in the family Veneridae

Veneridae

The Veneridae or venerids, also known as the Venus clams, are a very large family of minute to large, saltwater clams, marine bivalve molluscs. There are over 500 living species of venerid bivalves, most of which are edible, and many of which are exploited as a food source.Many of the most...

, the Venus clams.

The genus Mercenaria includes the quahogs, Mercenaria mercenaria, the northern quahog or hard clam

Hard clam

The hard clam , also known as a quahog , round clam, or hard-shell clam, is an edible marine bivalve mollusk which is native to the eastern shores of North America, from Prince Edward Island to the Yucatán Peninsula...

, and M. campechiensis, the southern quahog. These two species commonly hybridise where their ranges overlap.

Other species within the genus include the venus clam M. stimpsoni found in north Pacific waters.

All these species were formerly placed in the related genus Venus

Venus (genus)

Venus is a genus of small to large saltwater clams in the family Veneridae, which is sometimes known as the Venus clams and their relatives. These are marine bivalve molluscs....

. Several other species are known only from fossils.

Species

The World Register of Marine Species accepts the following extant species as valid:

• Mercenaria campechiensis (Gmelin, 1791) - Southern quahog
• Mercenaria mercenaria (Linnaeus, 1758) - Northern quahog
  Hard clam
  The hard clam , also known as a quahog , round clam, or hard-shell clam, is an edible marine bivalve mollusk which is native to the eastern shores of North America, from Prince Edward Island to the Yucatán Peninsula...
  
  
• Mercenaria stimpsoni (Gould, 1861) - Venus clam
• Mercenaria texana (Dall, 1902)

Fossil species

• M. corrugata
• M. druidi
• M. ochlockoneensis
• M. permagna
• M. rileyi
• M. tridacnoides

Miscellaneous information

The Mercenaria is the State Shell of Rhode Island

Rhode Island

The state of Rhode Island and Providence Plantations, more commonly referred to as Rhode Island , is a state in the New England region of the United States. It is the smallest U.S. state by area...

.