Pseudocerastes urarachnoidesBostanchi, Anderson, Kami, Papenfuss, 2006

Iranian spider viper

Photograph by Kian, CC BY, via iNaturalist

A ground-dwelling, active by day or night, meat-eating snake from the Saharo-Sindian region, reaching 530 mm nose to tail.

Reptilia › Squamata › Viperidae › Pseudocerastes

Grows to: 530mm; greatest recorded
Eats: Carnivorous
Active: Cathemeral
Lives: Terrestrial

Body length across Viperidae

Longer than only 13% of all vipers anyone has measured.

13% of 362 species are smaller87% larger

280 mmthe whole family, smallest to largest3,900 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 280 to 3,900 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

32 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: Near Threatened
Status assessed · the year the Red List last looked: 2022
Population trend: Decreasing
Red List criteria: B1b(v)

The animal itself

Limbs: None
Venomous: Yes
Fangs: At the front of the mouth

Size

Length nose to tail · greatest recorded: 530mm21 in
Body mass · greatestcomputed: 82.16g2.9 oz

How it lives

Diet: Carnivorous
How it hunts: Sit and wait
Active: Cathemeral
Where it lives: Terrestrial
Habitat: Rocky, Shrubland
Biome: Temperate Broadleaf & Mixed Forests
Region: Saharo-Sindian
Mainland or island: Mainland
Elevation · above sea level: 200–300m
Range size: 36,752km²

Breeding

Reproduction: Oviparous
Average clutch: 9
Eggs or young per clutch: 8–10eggs
Clutches a year: 1per year
First breeds at: 48months

Naming and history

Suborder: Serpentes
Infraorder: Alethinophidia
Subspecies: No
Described by: Bostanchi, Anderson, Kami, Papenfuss
Moved to another genus · since it was first described: No
Described in: 2006
Type locality: Iran

Keeping one

21 in × 10.5 in × 15.5 in(53 × 27 × 40 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 21 in (530 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 Iranian spider viper. 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.

10kJ per day

Worked out for an animal of 82 g, the heaviest recorded for Iranian spider viper — 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 the young develop
— Gestation or incubation
— Mean clutch · smallest reported
— Mean clutch · largest reported
— Clutches in a year
— 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
— Colour on the back
— Pattern on the back
— Pupil
— Sex decided by
— Active season · shortest recorded
— Active season · longest recorded
— Density · lowest recorded
— Density · highest recorded
— Home range · largest recorded
— Active in

Others in Viperidae

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). Pseudocerastes urarachnoides. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/pseudocerastes-urarachnoides

@misc{pseudocerastes_urarachnoides_2026,
  title  = {Pseudocerastes urarachnoides},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/pseudocerastes-urarachnoides}
}

Sources

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