All Angles Creatures
Squamata · PseudoxyrhophiidaeEntry 607 of 21,572
Yellow-flanked Keeled Snake, Alluaudina bellyi

Reptilia · Squamata

Alluaudina bellyiMocquard, 1894

Yellow-flanked Keeled Snake

Photograph by Samuel GUIRAUDOU, CC BY, via iNaturalist

A ground-dwelling, nocturnal, meat-eating snake from the Madagascan region, reaching 447 mm nose to tail.

ReptiliaSquamataPseudoxyrhophiidaeAlluaudina

Grows to
447mm
greatest recorded
Eats
Carnivorous
Active
Nocturnal
Lives
Terrestrial
Body length across Pseudoxyrhophiidae

Longer than only 25% of all species in Pseudoxyrhophiidae anyone has measured.

25% of 87 species are smaller75% larger
195 mmthe whole family, smallest to largest1,700 mm

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 195 to 1,700 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

31 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

Still living
Extant
Conservation status
Least Concern
Status assessed · the year the Red List last looked
2011
Population trend
Decreasing

The animal itself

Limbs
None
Colour on the back
Black, Brown
Pattern on the back
Uniform
Pupil
Vertical slit
Fangs
At the back of the mouth

Size

Length nose to tail · greatest recorded
447mm17.5 in

snakes only in this source

Body mass · greatestcomputed
26.38g0.93 oz

computed from length by a family-level allometric equation, not weighed

How it lives

Dietcomputed
Carnivorous

no actual data but can be imputed as carnivorous like all snakes

Active
Nocturnal

O'Shea 2018

Where it lives
Terrestrial
Habitat
Forest
Biome
Tropical & Subtropical Moist Broadleaf Forests
Region
Madagascan
Mainland or island
Found only on islands
Elevation · above sea level
400–650m

400-650 (O'Shea 2018)

Range size
40,651km²

Breeding

Reproduction
Oviparous

Feldman et al. 2015

Average clutch
5

the single figure reported — Cadle, de Freitas, Penny, Adams, Gonzales, Castañeda, ..., and Greenfield, 2009, Proc. Calif. Acad. Sci., 60:461-502

Largest clutch recorded
5eggs

max=5 (O'Shea 2018), mean=5 (Feldman 2015)

Mean clutch
5eggs

Naming and history

Suborder
Serpentes
Infraorder
Alethinophidia
Subspecies
No
Described by
Mocquard
Moved to another genus · since it was first described
No
Described in
1894
Type locality
Madagascar

Keeping one

17.5 in × 8.75 in × 13 in(45 × 22 × 34 cm)

Minimum length × width × height, for one animal. Bigger is always better.

The standard sizes snakes as a fraction of total length: 1 × 0.5 × 0.75.

Mindestanforderungen an die Haltung von Reptilien (Sachverständigengutachten), German Federal Ministry for Nutrition, Agriculture and Forestry, Animal Welfare Division, 10 January 1997. The standard states these floor areas are recommendations rather than binding limits.

From this animal’s own total length of 17.5 in (447 mm), at 1 × 0.5 × 0.75 times it, following the German federal welfare standard — how this is worked out.

No preferred body temperature has been recorded for Yellow-flanked Keeled Snake. Rather than repeat a number from a care sheet, this page leaves it out.

Feeding

A prey item should be between the same width as the widest part of the snake's body and about 1.5 times that width.

Widely used across snake husbandry references. An alternative formulation gives prey at 10-15% of the snake's body mass. This is established practice, not a measurement.

4kJ per day

Worked out for an animal of 26 g, the heaviest recorded for Yellow-flanked Keeled Snake — 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.

  • 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
  • Largest juvenile · shell length
  • Egg length
  • Egg width
  • Body mass · a typical adult
  • Body mass · adult female, mean
  • Body mass at hatching
  • Longest recorded life
  • Preferred body temperature · chosen in a laboratory gradient
  • Body temperature when active · measured in the wild
  • Eats arthropods
  • Eats vertebrates
  • Eats plant matter
  • How it hunts
  • How the young develop
  • Gestation or incubation
  • Smallest clutch recorded
  • Clutches in a year
  • 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
  • Venomous
  • Body temp in the wild · lowest mean recorded
  • Body temp in the wild · highest mean recorded
  • Sex decided by
  • Red List criteria
  • Active season · shortest recorded
  • Active season · longest recorded
  • Density · lowest recorded
  • Density · highest recorded
  • Home range · largest recorded
  • Active in

Others in Pseudoxyrhophiidae

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). Alluaudina bellyi. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/alluaudina-bellyi

@misc{alluaudina_bellyi_2026,
  title  = {Alluaudina bellyi},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/alluaudina-bellyi}
}

Sources

  1. Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
  2. 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.
  3. Catalogue of Life (dataset 3LR), used under CC BY.
  4. Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.