Reptilia · Testudines
Astrochelys radiataShaw, 1802
Radiated Tortoise
Photograph by Nigel Voaden, CC BY, via iNaturalist
A ground-dwelling, day-active, plant-eating tortoise from the Madagascan region, reaching 41 cm across the shell.
Reptilia › Testudines › Testudinidae › Astrochelys
- Grows to
- 400mm
- greatest recorded
- Eats
- Herbivorous
- Active
- Diurnal
- Lives up to
- 85years
Longer than 69% of all tortoises anyone has measured.
The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 99.8 to 1,200 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.
What is known
28 sourced facts, each taken from a named scientific dataset. How to read these.
Cited from a dataset unless a row is marked otherwise.
Standing in the world
- Conservation status
- Critically Endangered
- Population trend
- Decreasing
The animal itself
- Colour on the back
- Black
- Pattern on the back
- Blotched
- Pupil
- Round
- Venomous
- No
- Fangs
- None
- Longest recorded life
- 85years
Size
- Length nose to tail · greatest recorded
- 400mm15.5 in
- Shell length, front to back · greatest recorded
- 410mm16 in
- Largest juvenile · shell length
- 40mm1.5 in
- Body mass · greatestcomputed
- 16,000g35 lb
- Body mass at hatching
- 61g2.2 oz
total length, tail included — Colston, Kulkarni, Jetz, and Pyron, 2020, BMC Evol. Biol., 20:81
straight carapace length, measured in a line rather than over the curve
largely converted from length by allometry in the source
How it lives
- Diet
- Herbivorous
- How it hunts
- Active foraging
- Active
- Diurnal
- Where it lives
- Terrestrial
- Habitat
- Marine Coastal, Shrubland
- Region
- Madagascan
Plants
Breeding
- Reproduction
- Oviparous
- Sex decided by
- Temperature
- Average clutch
- 5eggs
- Eggs or young per clutch
- 3–12eggs
- Clutches in a year
- 3per year
Naming and history
- Subspecies
- No
- Described by
- Shaw
- Moved to another genus · since it was first described
- Yes
- Described in
- 1802
Keeping one
Radiated Tortoise is assessed as Critically Endangered on the IUCN Red List. Species at risk in the wild are often covered by CITES and by national law, which decide what may be bought, sold, moved across a border or kept at all — and captive-bred and wild-caught animals are usually treated differently. Check the rules where you are before acquiring one. Nothing below is a judgement about keeping this species; it is what a published welfare standard says about space, and what the animal itself was measured doing.
10 ft 9 in × 5 ft 5 in(328 × 164 cm)
Minimum floor length × width, for one animal. Bigger is always better. The standard sets no height for turtles and tortoises.
The standard sizes this genus at 8 times carapace length, with the width half the resulting length.
For a third and fourth turtle the standard asks for at least 10% more floor area each, and 20% more from the fifth onwards.
Water depth is set against the animal's carapace width rather than its length, so no figure is given here. Dry-country tortoises need no water area, only occasional bathing; tortoises from wetter regions need a water dish.
Swiss law reaches the same 8 × 4 of carapace length for land tortoises, arrived at separately from the German gutachten.
Gutachten über Mindestanforderungen an die Haltung von Reptilien (Sachverständigengruppe tierschutzgerechte Haltung von Terrarientieren), German Federal Ministry, 10 January 1997, section 5. The standard states these are recommendations rather than binding limits.
Swiss Tierschutzverordnung (TSchV), SR 455.1, Anhang 2, Tabelle 5 — legally binding minimum enclosure sizes, which give every land tortoise 8 × 4 body lengths for two animals.
From this animal’s own carapace length of 16 in (410 mm), at 8 times it — how this is worked out.
No preferred body temperature has been recorded for Radiated Tortoise. Rather than repeat a number from a care sheet, this page leaves it out.
Feeding
Prey size does not apply. A herbivore's diet is judged on fibre, on the ratio of calcium to phosphorus, and on avoiding plants high in oxalates.
The animal does not take prey items. This is established practice, not a measurement.
1071kJ per day
Worked out for an animal of 16,000 g, the heaviest recorded for Radiated Tortoise — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.
An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.
What nobody knows
These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.
- — Still living
- — Length snout to vent · greatest recorded
- — Length snout to vent · adult female mean
- — Length snout to vent · adult male mean
- — Length snout to vent · adult mean
- — Female length · mean, nose to tail
- — Length nose to tail · adult male mean
- — Length nose to tail · adult mean
- — Largest female · snout to vent
- — Largest male · snout to vent
- — Largest female · shell length
- — Largest male · shell length
- — Hatchling length · snout to vent
- — Hatchling length · nose to tail
- — Largest juvenile · snout to vent
- — Egg length
- — Egg width
- — Body mass · a typical adult
- — Body mass · adult female, mean
- — Preferred body temperature · chosen in a laboratory gradient
- — Body temperature when active · measured in the wild
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — Gestation or incubation
- — Mean clutch · smallest reported
- — Mean clutch · largest reported
- — Clutches a year · fewest
- — Clutches a year · most
- — First breeds from · youngest recorded
- — First breeds by · oldest recorded
- — Hatchling length · smallest recorded
- — Hatchling length · largest recorded
- — Age at first breeding · female
- — Mature from · youngest recorded
- — Mature by · oldest recorded
- — Size at maturity · smallest recorded
- — Size at maturity · largest recorded
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Limbs
- — Status assessed · the year the Red List last looked
- — Red List criteria
- — Biome
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Suborder
- — Infraorder
- — Type locality
- — Active in
- — Mainland or island
- — Lowest it lives · above sea level
- — Highest it lives · above sea level
- — Range size
Others in Testudinidae
Take this data
Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.
This species as JSON · the whole dataset
Cite this page
The Reptile & Amphibian Encyclopedia (2026). Astrochelys radiata. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/astrochelys-radiata
@misc{astrochelys_radiata_2026,
title = {Astrochelys radiata},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/astrochelys-radiata}
}Sources
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
- Catalogue of Life (dataset 3LR), used under CC BY.
- Moura, M. R. et al. TetrapodTraits: a database of 33,281 tetrapod species. Used under CC BY 4.0. Observed values only; this encyclopedia does not publish its imputed predictions.