Starfish facts!

Grab your snorkels, gang, and join us as we discover the secrets of one of the ocean’s most peculiar creatures! Ready? Then check out our fascinating starfish facts…

Phylum: Echinodermata
Family: Asteriidae

Classification: Invertebrate
IUCN status: Not Evaluated
Lifespan (in wild): 35 years
Weight: Up to 5kg
Body size: 1-65cm, depending on species
Diet: Carnivore
Habitat: Ocean
Range:

First things first – despite their common (and very misleading!) name, starfish (or sea stars) are not actually fish. Since they don’t have a backbone, they belong to a group of species called invertebrates, which also includes urchins and sponges.

There are around 1,600 different species of starfish living in the world’s oceans, where they occupy every type of habitat including tidal pools, rocky shores, sea grass, kelp beds and coral reefs. Some starfish are even found on sandy seabeds 9,000 metres deep!

Most starfish sport spiny skin and five arms surrounding a central disk-shape body – although some can grow as many as 50 arms. Their arms are covered with pincer-like organs and suckers that allow the animal to slowly creep along the ocean floor. They also have eyespots on the tips of the arms, which allow the starfish to sense light and dark, and help it find food.

Favourites on the starfish’s menu include mollusks like clams, oysters and snails. And it has a pretty impressive way of eating! After attaching its body to the chosen prey, the starfish extends its stomach out through its mouth. Substances (called enzymes) from the stomach then begin to digest the food. This allows the nutritious grub to pass inside the stomach, which in turn retracts back into the body where digestion is complete. Cool, eh? Tiny organisms that fall victim to the super starfish can be swallowed whole.

Starfish predators include certain fish species, sharks, manta rays and even other starfish! To help protect themselves, these incredible invertebrates have evolved several effective defence mechanisms. As well as their tough, prickly, armourlike skin, some have striking colours that camouflage them amongst plants and coral, or scare off potential attackers. And check this out, too – these cool creatures are able to regrow lost or damaged limbs! If under attack, some starfish will even shed an arm to escape the predator. Cunning stuff!

Starfish aren’t social creatures – instead they are solitary and spend most of their life alone. They will, however, sometimes congregate in large groups during certain times of the year to feed.

Picture credits –   Blue starfish: Song Heming, Dreamstime. Red starfish: Mrtolc, Dreamstime. Yellow starfish: Natalie11345, Dreamstime.

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COMMENTS1

Rutwa cha

Nice
Isaac

Cool! I love starfish!
Enya

This helps me learn more and i also share some of this to my classmates
Loulou

Great
Cool
lion

I use this for my writing
lion
Sofia

Cool
Sofia
Jayden

Nice
Luis
Faisa

Amizing Wow
yusriyah

cool
Tyler
Noa

You describe the words Great
Kimberly

Do starfish get along with other sea creatures?
star fish have butts
Hi
Nice

Nice
Home learning, Thursday 21st May – Ellel St John's CE Primary School

[…] https://www.natgeokids.com/uk/discover/animals/sea-life/starfish-facts/ […]
Olivia

cool
Issy

AWESOME!
smithd1

AMAZING!!!
Ivy

Soooo cool!
Zara

Cool
ramona

starfish are amazing. I like how they have no back bone.
Ngarewa

Very interesting. I love star fish
Charlize

I love starfish!
gordon

cool!!!!!!!!!!!!!!
A.y17

I have sen a blue star fish
bdbhds

wow i didnt know any of that ;)
BOB

AMAZING!!!
lucy

wow amazing