Common BI Mollusks

Recently the beaches have opened for the 2014 shellfish season. Interestingly enough, Block Island is home to a great variety of mollusks and shellfish. Here is a rundown of the island's most common mollusks. But first, let's define what a mollusk is. According to Merriam-Webster, a mollusk is "any of a large phylum (Mollusca) of invertebrate animals (as snails, clams or squids) with a soft unsegmented body  usually enclosed in a calcareous shell." To put it simply a mollusk is broadly speaking a shellfish. The following is a list of common mollusks that you will encounter on Block Island.

1.) Quahog (pronounced co-hog) - You may be familiar with this one. It is one of the most fished mollusks on the island. Often, found in rather sandy/muddy beaches the quahog is an iconic New England mollusk. The Quahog is the most important ingredients in New England Clam Chowder. Not only is this mollusk used as a main ingredient in food, they can live for more than 30 years! The purple coloring on the inside of a Quahog shell was used as currency and jewelery by the Wampanoag people. They called the beads wampum.

 Quahog using its foot to move across the ocean's floor

Quahog using its foot to move across the ocean's floor

2.) Razor Clam - Razor clams named after their long narrow shape are are common to Block Island. These interesting looking mollusks are found on sandy beaches in Northern Europe, Eastern Canada and as far south as New Jersey. Like the Quahog, the Razor clam also has a foot as a locomotive organ. The razor clam uses its foot to bury itself out of harms way. The razor clam, due to its comparatively thin shell, is a favorite feast for many shore birds. Therefore, depth is the clam's best ally.

 Razor clam shell

Razor clam shell

3.) Atlantic Ribbed Muscle - These muscles are native to the Atlantic coast of North America. They can be found in the intertidal zones as far north as the Gulf of St. Lawrence in Canada to as far south as the eastern coast of Florida. They have specialized organs called byssal threads that help to adhere them to hard surfaces. These threads are so strong that they can withstand hurricane force winds (something that we experienced over the last couple of days). These ribbed muscles are commonly found in clusters of three or more, a behavior probably evolved to  aid with reproduction.

 Atlantic Ribbed Muscle

Atlantic Ribbed Muscle

4.) Common Periwinkle - The Common Periwinkle is robust intertidal species of edible sea snail with a dark and occasionally banded shell. Periwinkles are ubiquitous in the Atlantic Ocean and are native to the rocky shores of the northeastern states. Unlike the previously mentioned species, this mollusk has gills and a specialized hydrophobic trap door called a operculum used to keep hydrated even when away from water for extended periods of time. Periwinkles are often found at low tide clinging to the side of rocks or seaweed.

 A common periwinkle with it's operculum open.

A common periwinkle with it's operculum open.

5.) Bay Scallop- Although this one maybe a bit more difficult to find, I assure you they are out there. The Bay Scallop spends most of its time in eelgrass beds and sandy/muddy bottomed subtidal zones. They are one of the few mollusks to filter feed above water. Unlike any other creature above, when threatened the bay scallop swims away from its predators by forcing water in and out of its body. One of the most unique features of the Bay Scallop is that it has 30-40 bright blue eyes along the edge of the shell. It uses these eyes to detect movements and shadows to assist with predator identification. They reach sexual maturity at about 1 year of age and rarely live past the age of 3.

 Bay Scallop opened to see rows of blue eyes.

Bay Scallop opened to see rows of blue eyes.

Please note that as the next month progresses, this list may grow to accommodate  mollusks that seem to become more popular. For now, go out, explore and see how many you can locate! ENJOY!