The best time to search for sand dollars is in the morning during a low tide. The sand dollar's tiny moveable spines, which encompass the entire shell, are what enables it to eat a diet of crustacean larvae, small copepods and algae.
In their live state, they are usually muddy grey circular, flat and covered with short spines. Several other sand dollars … The notched sand dollar has holes along the edge as you can see from the image below taken from Wikimedia.
An identification guide to the many seashells, starfish, sanddollars, and more found along the shore . Some species of snails will also eat sand dollar larvae. There are many different species of sand dollars throughout the world. Most sand dollars live in tropical shallow-water places (e.g., Africa, Singapore, Indonesia, the Bahamas, etc) but a few do live in cold to temperate waters (e.g., Dendraster excentricus on the west coast of North America) Sand dollars are related to sea cucumbers and starfish but in fact they belong to the order Clypeasteroida.
One species of sand dollars (Dendraster excentricus of the US) is known to settle in response to a substance released by adults. The bodies of adult sand dollars display a petal-like pattern. Identification guide. Some species thrive in tropical zones and the Caribbean Seas.
As with other sand dollars this species is very flat, at least 5x as wide as tall.
They differ in size and shape. There are some 75 genera of sand dollars, 29 living and 49 fossil (following Mooi 1989) with quite a few species. Description: A highly flattened, irregular echinoid (sand dollar) with very short, dark spines when alive that make it appear almost velvety (see photo above).Dead individuals have a gray test and a clearly visible, off-centered petalidium on the aboral side ().The excentricus in the name refers to the off-center petalidium.Diameter to 8 cm.
This might explain why so many sand dollars of the same species may be found in one place. The keyhole sand dollar is similar to the arrowhead, but has five small holes. Usually a snail will not attack a fully grown sand dollar because the sand dollars are larger than most snails. The term sand dollar refers to a species of flat burrowing sea urchins that have a rigid skeleton that allow them to move across the floor of the water. All other echinoids in the area are at least half as tall as wide. Therefor, there are many genera of sand dollars. Sand dollars are actually an entire order of invertebrate animals. This guide is devoted to help in identifying the many seashells and other sealife that can be found along the shore. However, the Common Sand Dollar belongs to the genus Echinarachnius. These snails slowly chew on the bodies of baby sand dollars or on dead sand dollars. Sand Dollar Information. These sand dollars live in the Caribbean, Gulf of Mexico, and much of Central America. The sand dollars sold are the bleached bodies of the echinoderm, usually a snowy white. The 'sand dollar' term originates from its resemblance to a large silver coin.
Their size can be a fraction of an inch to more than 6 inches. How to Distinguish from Similar Species: This is the only species of sand dollar found in Washington and Oregon. There are different types of sand dollars. Examples include: True Arrow Head Sand Dollars – Sturdier and larger than other types, this sand dollar is often used for painting beach scenes and souvenirs. The holes are used in part for helping the creature sink into the sand, where it lives and feeds. Seashells from the Ocean's Edge Pictorial Index (Note: See also alphabetical index.)
Sand dollars are found on sandy bottoms, reef flats below low tide waters.