Shellfish Identification

Maine is fortunate to have a rich variety of molluscan or bivalve shellfish in its coastal waters.
Some of the most frequently encountered species are easy to identify by their shell shape and color.  Bivalve shellfish are filter feeders and therefore are impacted by environmental pollution and biotoxin.  It is important you always check if an area is open before you harvest.  The Department of Marine Resources (DMR) posts pollution closures here: http://www.maine.gov/dmr/shellfish-sanitation-management/closures/pollution.html and biotoxin closures here: http://www.maine.gov/dmr/shellfish-sanitation-management/closures/psp.html

Soft Shell Clams (Mya arenaria)
Soft shell clams live in mud, sand and gravel intertidal areas. It takes about three to four years for a clam to grow to legal size, which is two inches.  Harvest season is year round, peak is May through October.  Soft shelled clams are regulated by the state DMR and most coastal towns.  Many towns require recreational licenses.  Recreational limit is 1 peck per person daily. No state license is required for recreational harvest.
Other names: steamers, longnecks

Sofshell Clams
Photo Credit:  Bangor Daily News

Mussels (Mytilus edulis)
The blue mussel is a common native bivalve mollusks that lives from the intertidal zone to depths of several hundred feet, and is found frequently clinging to the rocky shoreline. Mussels can be harvested all year.  Mussels are regulated by DMR. The personal use limit for recreational harvest of mussels is 2 bushel per person daily.
Other names: common mussel

https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Blue_mussel_Mytilus_edulis.jpg/1280px-Blue_mussel_Mytilus_edulis.jpg

Photo Credit: Wikipedia

Hard Clam (Mercenaria mercenaria)
Hard clams are found in the sand and mud habitats of the intertidal and sheltered subtidal.  They are referred to by different names depending on their size. In the order of largest to smaller, these clams are called: Quahogs (Chowderhogs), Cherrystones, Topnecks, Littlenecks, and Countnecks. Hard clams are regulated by DMR and a few coastal towns. Many towns require recreational licenses. No state license for recreational harvest.  The recreational harvest limit is 1 peck per person daily.
Other names: round clam, cherrystones, littlenecks, countnecks

Hard Clams
Photo Credit:  wikipedia

Atlantic Surf Clam (Spisula solidissima)
Surf clams are very large and fast growing clams which can grow to 8 inches or more, and weigh over a pound. They live burrowed into the sand beneath the turbulent waves of the surf breaker zone. Surf clams are regulated by DMR and some coastal towns.  Many towns require a recreational harvest license, no state license for recreational harvest. The recreational harvest limit is 3 bushels per person daily, unless a municipal ordinance further restricts the limit.
Other names: bar clam, hen clam, skimmer, sea clam

Surf Clams
Photo Credit:  Maine Clammer’s Association

American or Eastern Oyster (Crassostrea virginica)
The American or Eastern oyster is native to the east coast of North America.  They have two rough, whitish, irregular shells.  They naturally grow on oyster reefs but most of Maine’s American oysters are now from aquaculture lease sites.  American oysters are regulated by DMR and a few coastal towns. Many towns require a recreational license.  In the Damariscotta River, there is a Vibrio Control Plan in place that restricts recreational harvest from May 1st to October 1st each year.
Other names: Wellfleet oyster, Virginia oyster, common oyster

American Oysters
Photo Credit:  Chesapeakebay.net

European Oysters (Ostrea edulis)
European Oysters are characterized by their rounder, flatter shell.  European oysters were first grown by aquaculturists in Maine, but established wild populations.  European oysters are regulated by DMR and a few coastal towns. Many towns require recreational licenses.  In the Damariscotta River, there is a Vibrio Control Plan in place that restricts recreational harvest from May 1st to October 1st each year.  There is a seasonal closure statewide from June 15th to September 15th every year. Minimum harvest size is 3 inches. Recreational harvest is limited to 1 peck.
Other names: flat oyster, Belons, mud oyster, edible oyster

European Oysters
Photo Credit:  Natureinfocus.wordpress.com

Atlantic Razor Clams (Ensis directus)
Brittle, bivalve clams most commonly found from Canada to New England and are distinguished by their long thin shells.  Razor clams are primarily found in shallow subtidal flats close to the shoreline.  Harvested Razor Clams generally range in length between 4-6 inches. Razor clams are regulated by DMR and a few coastal towns. Many towns require recreational licenses. The minimum size for harvest is 4 inches. 
Other names: American jackknife clam,

Razor Clams
Photo Credit:  Maine SeaGrant

Mahogany Quahog (Arctica islandica)
Mahogany quahogs are small hard shell clams that are harvested from Maine’s subtidal waters. Mahogany quahogs are typically harvested at about 1   - 2   inch shell length. Legal size is one inch thickness measured across the hinge width.  Mahogany quahogs are fish for by draggers and regulated by DMR and the National Marine Fisheries Service.  The personal use limit for Mahogany Quahogs is 3 bushels per person daily.
Other names: ocean quahog

Mahogany Quahogs
Photo Credit:  Maine Clammer’s Association

Common Periwinkle (Littorina littorea)

The common periwinkle is the most common intertidal snail.  Common Periwinkles grow to 1   inches in length.  Minimum size is determined by a numerical count.  If a one quart sample contains more than 220 periwinkles they are considered undersize.  The personal use limit is two quarts per day without a license.

Littorina littorea 001.jpg 

Photo Credit: Wikipedia

Common Moon Snail (Euspira heros)

Moon snails are a large species of snail gray to tan in color that can grow to 4 inches in shell length.  These snails are found subtidally but can also be found along beaches.

Other names: northern moon shell

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Photo Credit: intertidal-novascotia.blogspot.com

Waved Whelk (Buccinum undatum)

Waved whelks are medium sized with both axial and spiral ridges on their shell.  Adult waved whelks are two to four inches in length and are found subtidally.  Legal size is 2   inches shell length.  The personal use limit is up to   bushel of whelks per day without a license.

Other names: northern whelk, edible whelk, European whelk

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Photo Credit: Gulfofme.com

Stimpson’s Whelk (Colus stimpsoni)

Stimpson’s whelks have a spindle-shaped shell that is dark in color.  Adults are 1 to 3 inches in length.  They are found subtidally to deep water. 

Other names: Stimpson’s colus

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Photo Credit: Sciencesource.com