Radiated Tortoise

Astrochelys radiata

A critically endangered Madagascar tortoise named for the yellow star-like lines on its high, domed shell.

Checking teacher reviews…

Teacher? Sign in to review this page →Report a mistake

About the Radiated Tortoise

Radiated tortoises live in dry, spiny forests in far southern and southwestern Madagascar. Each plate on the shell has yellow lines spreading out from the center, which helps them hide in leaf litter. They grow up to about 15.5 inches long and 23 pounds. Grazing on grass makes up 80 to 90 percent of their diet, and they also eat fruit and cactus pads, spines and all.^[1]

Quick facts

Scientific name: Astrochelys radiata^[1]
Size: Up to about 15.5 inches long.^[1]
Weight: Up to about 23 pounds. The largest on record weighed 55 pounds.^[1]
Lifespan: Thought to live up to 100 years.^[1]
Diet: Herbivore. Mostly grass, plus fruit, succulents and cactus.^[1]
Habitat: Dry, spiny forests, plateaus and coastal sand dunes.^[1]
Where it lives: Southern and southwestern Madagascar; introduced to Réunion and Mauritius.^[1]
Babies: One to five eggs per clutch, which hatch in five to eight months.^[1]
Conservation status: Critically Endangered (IUCN Red List, assessed 2008).^[2]

Fun facts

The yellow lines on its shell radiate out like stars, which is how it got its name.^[1]
Radiated tortoises eat cactus pads, even the spines.^[1]
Some people in Madagascar have a taboo against harming these tortoises.^[1]

Vocabulary

scute: One of the bony plates on a turtle's shell, covered with keratin.
tortoise: A turtle that lives on land.
poaching: Hunting or capturing animals illegally.
taboo: Something a culture's rules say people must not do.
critically endangered: A conservation label meaning a species faces an extremely high risk of dying out in the wild.

See it in person

Zoo AtlantaAtlanta, Georgia · All AnimalsSee this animal on the zoo's website ↗

Sources

[1] Zoo Atlanta. “Radiated Tortoise.” https://zooatlanta.org/animal/radiated-tortoise/ (accessed 2026-10-02)
[2] IUCN Red List of Threatened Species. “Astrochelys radiata (Radiated Tortoise).” https://www.iucnredlist.org/species/9014/12950491 (accessed 2026-10-02)

Facts last checked 2026-10-02.

More Turtles and Tortoises

A large African spurred tortoise walking across green grass.

African Spurred TortoiseCentrochelys sulcata (also called Geochelone sulcata)The largest mainland African tortoise, a burrowing plant-eater of the dry lands south of the Sahara, also called the sulcata tortoise.

An alligator snapping turtle with a ridged, spiky shell resting on grass.

Alligator Snapping TurtleMacrochelys temminckiiThe largest freshwater turtle in the United States, which lures fish into its open jaws with a worm-like bit on its tongue.

A diamondback terrapin with a patterned shell and spotted gray skin walking on grass.

Diamondback TerrapinMalaclemys terrapinA colorful turtle of coastal salt marshes from the Atlantic to the Gulf of Mexico, the only turtle besides sea turtles that lives in brackish water.

An eastern box turtle with an orange-and-brown patterned shell walking on pavement.

Eastern Box TurtleTerrapene carolinaA land turtle of the eastern United States that can close its shell like a box and may live more than 100 years.

A mata mata turtle with a flat, fringed head resting on stones underwater.

Mata MataChelus fimbriataA camouflaged Amazon turtle with a flat head and snorkel nose that vacuums up fish by suddenly opening its mouth.

Three pancake tortoises with flat brown shells resting among rocks and straw.

Pancake TortoiseMalacochersus tornieriA critically endangered East African tortoise with a thin, flat, flexible shell that hides in rock cracks instead of in its shell.