9.52 Sand Dollar Facts

Sand dollars are fascinating creatures that live on the ocean floor. Learn about their characteristics, habitat, and diet, and find out why people tell stories about these amazing animals!

What Is a Sand Dollar?

The name ‘sand dollar’ sounds like something a crab uses as money, but sand dollars have nothing to do with currency. Sand dollars are fascinating animals that live in the ocean. Their size and shape are similar to a silver dollar or other large coin, and they live in the shallow ocean waters just off sandy beaches.

Sand dollars are dark in color due to many spines that cover the outer skeleton.
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Physical Characteristics

Sand dollars are very flat and dark grey or green in color. They have hard outer skeletons that look sort of like a flattened shell, and the skeleton has a five-point design and little pores that the sand dollar uses to breathe in its own way. The skeleton is also covered by many, many little spines. This fuzzy-looking coat of spines helps the sand dollar move.

There’s an interesting thing about sand dollars: They’re the focus of many legends and stories. The five points on the skeleton look like a star, and this has inspired creative stories that have been passed down for generations. One such story is that the sand dollar’s five points are five doves, each depicting one of life’s elements: Earth, water, fire, air, and spirit.

Sand dollars often turn white after they die.
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Since sand dollars live in the water, it’s not common to see one in the wild. But many people come across dead sand dollars all the time. Sand dollars look a lot different when they’re dead. They typically turn from dark grey or green to white, an effect of being bleached by sunlight after being washed ashore. When the sand dollar is white, it’s a lot easier to see the five-point design.

1. Main points:

Sand dollars are ocean-dwelling animals with flat, hard outer skeletons and a distinctive five-point design. They are usually dark grey or green but turn white after death due to sun bleaching. Sand dollars have inspired various legends and stories, particularly regarding the symbolism of their five-point design.

2. Questions:

• Content Analysis: What are sand dollars and what do they look like?
• Thematic Analysis: How do the physical characteristics of sand dollars contribute to their movement and survival?
• Socio-cultural Analysis: What is the cultural significance of the five-point design on sand dollars?

3. Further Discussion:

• What role do sand dollars play in the ocean ecosystem?

4. Answers:

• Content Analysis: "Sand dollars are fascinating animals that live in the ocean… They have hard outer skeletons that look sort of like a flattened shell."
• Thematic Analysis: "The skeleton is covered by many little spines… This fuzzy-looking coat of spines helps the sand dollar move."
• Socio-cultural Analysis: "The five points on the skeleton look like a star… One such story is that the sand dollar’s five points are five doves, each depicting one of life’s elements: Earth, water, fire, air, and spirit."

Habitat and Diet

These creatures live along the bottom of shallow areas of the ocean and have been found in the Atlantic and Pacific oceans. Living sand dollars tend to inhabit the shallow waters of the ocean, as living near the sand or mud is helpful for their survival.

Sand dollars are hunted by different types of fish and crabs that live along the sandy floors of the ocean. One way these animals survive is by burying deeper into the sand so they are hidden from predators. They also ingest sand through the mouth hole in the middle of the skeleton. This makes them heavier, and it can also help them stay low to the ocean floor away from predators and safe from ocean currents.

Sand dollars move along the sandy shore looking for food, and they feed on plankton, wich are tiny organisms that float in ocean currents. The sand dollar eats through a mouth hole in the middle of the skeleton. There are tiny jaws surrounding this hole, and these jaws help to crunch food that is gathered by the spines and moved toward the mouth.

A sand dollar is relatively small.
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1. Main points:

Sand dollars live in shallow ocean areas, primarily in the Atlantic and Pacific oceans. They have adapted survival strategies, such as burying into the sand and ingesting sand to stay anchored to the ocean floor. Their diet consists mainly of plankton, which they consume through a mouth hole in their skeleton, aided by tiny jaws.

2. Questions:

• Content Analysis: Where do sand dollars live and what are their survival strategies?
• Thematic Analysis: How do sand dollars feed and what is their diet?
• Socio-cultural Analysis: What is the ecological significance of sand dollars in ocean ecosystems?

3. Further Discussion:

• How do the feeding habits of sand dollars affect their role in the ocean’s food chain?

4. Answers:

• Content Analysis: "Sand dollars live along the bottom of shallow areas of the ocean… They bury deeper into the sand to hide from predators."
• Thematic Analysis: "Sand dollars feed on plankton… They eat through a mouth hole in the middle of the skeleton, with tiny jaws helping to crunch food."
• Socio-cultural Analysis: Sand dollars play a vital role in ocean ecosystems, both as prey for various fish and crabs and as consumers of plankton, contributing to the balance of the ocean’s food chain and nutrient cycles.

Lesson Summary

Sand dollars are flat, round, dark grey or green animals that live in sandy or muddy areas of shallow ocean waters. They move and gather food using many tiny spines that cover its outer skeleton. Sand dollars that are no longer living are white or grey and have a star pattern on the outer skeleton.