Mollusk

Mollusk

False Angel Wing

Submitted by lupo on Sat, 10/16/2010 - 23:13

 
Latin Name: 
Petricolaria pholadiformis
Common Name: 
False Angel Wing
Description: 

The shell of this species can be up to 2¾ inches long. The thin elongate ovalish shaped shell is similar to a small angelwing but is missing the rolled-out, expanded hinge area. There is strong radial ribbing present on the end of the shell where the hinge is located. The color may vary from yellowish brown to white.

a false angel wing shell

A worn but still intact False Angel Wing shell.

 

Biology: 

The false angel wing typically burrows into hard surfaces, such as clay or peat, in intertidal zones. Their elongate shell is used to grind through the substrate, which forms a tubular burrow. Each individual will remain in its burrow for their entire lifetime. They extrude a siphon through their shell and burrow to filter water, which is how false angel wings obtain their food. Holes that remain after the death of an individual may be used by other organisms like crabs or other mollusks.

A view of a false angel wing shell that shows the left and right shells, partially broken, but still attached.

Petricolaria pholadiformis shell that shows the shape of the hinge.

 

Distribution: 

Canada to Uruguay.

Similar: 

Angel Wing, Fallen Angel Wing

an angel wing shell

The Angel Wing has a larger and more expanded hinge.

 

false angel wing

The False Angel Wing shell has an unremarkable hinge and does not contain a consistent pronounced ribbing throughout the entire length of the shell.

 

Abundance: 
Occasional

Jingle Shell

Submitted by lupo on Sat, 10/16/2010 - 21:40

 
Latin Name: 
Anomia simplex
Common Name: 
Jingle Shell
Description: 

Jingle shells are very thin and can be roughly circular to broadly ovate, from ¾ to 2 ¼ inches (~ 2 to 5.7 cm) long. The color varies with individuals exhibiting hues of yellow, orange, silver or white. The shell is translucent and is most commonly smooth with obvious growth lines. Some individuals have ridges or other patterns that mirror the substrate where they lived.

a larger and small jingle shell

Two jingle shells.

 

Biology: 

Shallow water, typically in bays or estuaries, from low tide water line up to 30 (~ 9 m) feet deep.

This bivalve attaches itself to hard objects in the water. This may be other shells or any hard substrate. Threads, known as byssus, are used for attaching themselves to an object. The byssus extrude through a hole in the lower shell. The upper shells can also be compromised by a boring predator. Many jingle shells found on the beach have a hole in them.

Distribution: 

Southern Massachusetts to Brazil.

Flotsam and Jetsam: 

The name jingle shell refers to the sound a collection of these shells will make when you jostle them together. If you find a collection of these shells on the beach, simply hold a few of them in your closed hand and shake them to hear them jingle. This is one of the reasons you can find wind chimes made of these shells.

The coloration and general appearance of jingle shells have led to their having a number of interesting common names such as Mermaid’s toe nails (with the colors suggesting the use of nail polish!) and Neptune’s toe nails.

Anomia simplex are related to oysters hence another common name is “Saddle Oyster.” Unfortunately they have a bitter taste and are not good eating.

a small jingle shell on the beach

Anomia simplex shell washed up on the beach.

 

Abundance: 
Common

Atlantic Surf Clam

Submitted by lupo on Sat, 10/16/2010 - 13:58

 
Latin Name: 
Spisula solidissima
Common Name: 
Atlantic Surf Clam
Description: 

surf clams are more oval or triangular than round

a surf clam shell on the sand

The distinctive and familiar shell of the surf clam.

 

Biology: 

The Atlantic Surf Clam is the largest clam on the Atlantic coast. They have a strong, triangular shaped, two-part or bivalve shell that can reach up to 6 inches across. Adult clams prefer to live in fine to medium grained sandy sediment. This may be in a nearshore location or in open waters that have suitable sandy bottoms, to a depth of 60 m. Densities do drop off at depths greater than 40 m. Adult surf clams do not move from place to place, preferring instead to stay in their sand burrows. Storms and strong currents can move them but they will rebury themselves quickly unless they become washed up onto a stable and harder to dig into beach.

This species is a plankton eating filter feeder. In turn, they are eaten by a wide range of other organisms including fish, sea stars, crustaceans and other mollusks. Each species that eats the clams have their own way of getting into the shell to access the living parts of the surf clam. The moon snail drills a small hole in the surf clam’s shell, usually near the hinge. Gulls that find a larger clam will pick them up then drop them from the air onto hard surfaces such as a dock or sidewalk to break the shell.

Surf clams account for about 70% of all clams commercially harvested in the United States. They are sold chopped and canned, and are eaten in sauces and chowders. Fishermen also use the bellies of the clam as bait for stripped bass and other fish.

For various reasons harvesting Atlantic Surf Clams for human consumption is not allowed in numerous areas (e.g., Georges Bank, the New York Harbor Estuary) where the clam is exposed to being contaminated by bacteria and other organisms that can harm humans.

Life History: 

Spisula solidissima spawn in mid-July through early August and from mid- October to early November. Female and male gametes are released into the water where, upon meeting, the eggs are fertilized. Spawning is temperature dependent and depending on the year, only one spawning might occur. Eggs hatch into planktonic larvae that develop a shell just before they settle into the sand, which occurs after about 3 weeks of hatching. Surf clams can become sexually mature in as little as 3 months but they will not spawn until reaching a size of 40 mm. Surf clams can live 25 years or longer. Clams in deeper, open waters typically live longer that those that live in more turbulent areas close to shore.

Spisula solidissima lined up in the sand

A line of surf clams washed up on the beach.

 

Distribution: 

From the southern portion of the Gulf of St. Lawrence to Cape Hatteras, North Carolina. There are major populations of the Atlantic surf clam in Georges Bank, along the south shore of Long Island, along the coast of New Jersey and in the Delmarva Peninsula.

Similar: 

These shells are distinctive from the more rounded, and less common in New Jersey, Quahog shells.

Abundance: 
Common
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