Wednesday, April 28, 2010
I like Sand Dollars. I like the way they look in their natural state and I like how smooth and detailed they are in their sun bleached state. I like that I can see a lily, a poinsettia, and a star on them and you can find doves hiding inside them.
Keyhole Sand Dollar (dead) - all photos enlarge
Live Sand Dollar
I like that you can find them easily by pushing your toes through soft sand and slowly lifting them up to see them in either their natural (hairy) like state or smooth and white. I like that they can be found in the size of a nickel up to a salad plate. The name "sand dollar" comes from its the shape of its body which takes on a large, coin-like appearance. Commonly called a shell, the Sand Dollar is actually an echinoderm which means "spiny skinned" in Greek. A marine invertebrate that lives in the sandy bottoms of sheltered bays and open coastal areas. The starfish, sea urchin, sea cucumber and sand dollar are examples of the over 6000 species of echinoderms in our planet's salt waters.
Native to Florida and other areas of the world, Sand Dollars are actually the skeleton of several species of Sea Urchins. Sand Dollars are common to the southeastern U.S., Australian and Caribbean seas and are usually found on sandy bottoms in shallow water. The typical shell is flat, circular and about 3 inches in diameter. There are 12 different types of sand dollars and among those most well known are the Flat Round or common sand dollar, the Arrowhead, Pankcake, Keyhole (above) and the Sea Biscuit sand dollar
Common or Flat Round Sand Dollar
Arrowhead Sand Dollar
Pancake Sand Dollar
Sea Biscuit Sand Dollar
On the ocean bottom, sand dollars are frequently found together.
This is due in part to their preference for soft bottom areas, which are convenient for their reproduction. The sexes are separate and, as with most echinoids, they are conceived by external fertilization. Live sand dollars can be greenish, bluish or purple. Their highly modified spines and podia give them a velvet-like texture and appearance. The spines on the somewhat flattened underside of the animal allow it to burrow or to slowly creep through the sediment. As you can see in this video, they are a very slow moving creature.
Fine, hair-like cilia cover the tiny spines. Food grooves move food to the mouth opening, which is in the center of the star-shaped grooves on the underside of the animal . Its food consists of crustacean larvae, small copepods, diatoms, algae and detritus. Inside a sand dollar shell are five teeth, which are useful for scraping plankton from rocks. The teeth, which are found when the shell is broken open, are called 'doves' because they look like tiny white doves.
There is something magical about the Sand Dollar. It is light and delicate and yet manages to survive storms, predators and man stepping all over them in the watery shallows. When living, they have the appearance of velvet and when reduced to the skeletal structure they become pure white talismans of all sizes. I have collected them for years (always the dead ones found along the beach, never the live specimens) and utilized them in my wedding invitation as shown below.
Have a beautiful white shell wednesday and blessings to you and all you love. Sea Witch