Learning About Starfish

Facts and Resources For Learning About Starfish

Learning About Starfish
John White Photos / Getty Images

Starfish are fascinating creatures. With their  bumpy, five-armed bodies, it's easy to see how they got their name, but did you know that starfish aren't really fish at all?

Scientists don't call these ocean-dwelling creatures starfish. They call them sea stars because they aren't fish. They don't have gills, scales, or backbones like fish do. Instead, starfish are invertebrate marine organisms tbhat are part of the family known as echinoderms.

One feature that all echinoderms have in common is that their body parts are arranged symmetrically around a center point. For starfish, those body parts are their arms. Each arm has suckers that help starfish, who don't swim, move along and capture prey. Most of the 2,000 species of starfish have the five arms that inspired their name, but some have as many as 40 arms!

Starfish can regrow an arm if they lose one. That's because their vital organs are located in their arms. In fact, as long as an arm has part of the starfish's central disc, it can regenerate an entire starfish.

At the end of each of a starfish's five to forty arms is an eye that helps them locate food. Starfish eat things like clams, snails, and small fish. Their stomachs are located on the underside of their central body part. Did you know that a starfish's stomach can come out of its body to envelop its prey?

Another striking fact about starfish is that they don't have brains or blood! Instead of blood, they have a water vascular system that helps them breathe, move, and expel waste. Instead of a brain, they have a complex system of light - and temperature-sensitive nerves.

Starfish live only in saltwater habitats but are found in all Earth's oceans. They vary in sized based on the species but are usually between 4 and 11 inches in diameter and can weigh up to 11 pounds.

The lifespan of a starfish also varies by species, but many live up to 35 years. They can be found in a variety of colors such as brown, red, purple, yellow, or pink.

If you are fortunate enough to find a starfish in a tide pool or the ocean, you can safely pick it up. Just be very careful not to harm the starfish and make sure to return it to its home.

Learning About Starfish

To learn more about sea stars, try some of these excellent books:

Starfish by Edith Thacher Hurd is a 'Let's-Read-and-Find-Out About' story about starfish and how they live in the deep blue sea.

One Shining Starfish by Lori Flying Fish is a colorful counting book featuring starfish and other ocean-dwelling creatures. 

Star of the Sea: A Day in the Life of a Starfish by Janet Halfmann is a beautifully-illustrated book that weaves facts about starfish into a delightfully captivating tale.

Seashells, Crabs and Sea Stars: Take-Along Guide by Christiane Kump Tibbitts introduces a variety of marine life, including starfish. It includes tips for identifying several marine-dwelling creatures and features fun activities to try.

Spiny Sea Star: A Tale of Seeing Stars by Suzanne Tate provides easily-accessible facts about starfish with adorable illustrations.

Sea Star Wishes: Poems from the Coast by Eric Ode is a collection of ocean-themed poems, including those about starfish. Memorize a starfish poem or two as you study sea stars.

Resources and Activities for Learning About Starfish

Spend some time researching and learning about starfish using your library, the Internet, or local resources. Try some of these ideas:

  • Learn more about how starfish see with the eyes at the end of each of their arms.
  • Research starfish anatomy. Learn how they eat, breathe, and move.
  • Visit an aquarium or a fish store to see live starfish up close.
  • If you live near a beach, look for starfish in the tide pools.
  • Make a diorama featuring starfish, their habitat, and their prey.
  • Create an ABC book about starfish.
  • Do some research to find out what creatures other than starfish are members of the echinoderm family.
  • Learn about the dangers, such as predators and pollution, that starfish face.

Starfish, or sea stars, are enchanting creatures who play an important role in their environment. Have fun learning more about them!

Updated by Kris Bales

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Your Citation
Hernandez, Beverly. "Learning About Starfish." ThoughtCo, Aug. 27, 2020, thoughtco.com/lesson-2-learning-about-starfish-1834129. Hernandez, Beverly. (2020, August 27). Learning About Starfish. Retrieved from https://www.thoughtco.com/lesson-2-learning-about-starfish-1834129 Hernandez, Beverly. "Learning About Starfish." ThoughtCo. https://www.thoughtco.com/lesson-2-learning-about-starfish-1834129 (accessed February 6, 2023).