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Squamata · ViperidaeEntry 21,243 of 21,572
Portugese Viper, Vipera seoanei

Reptilia · Squamata

Vipera seoaneiLataste, 1879

Portugese Viper

Photograph by Marco Sommer, CC BY, via iNaturalist

A ground-dwelling, day-active, meat-eating snake from the Palearctic region, reaching 700 mm nose to tail.

ReptiliaSquamataViperidaeVipera

Grows to
700mm
greatest recorded
Eats
Carnivorous
Active
Diurnal
Lives up to
19years
Body length across Viperidae

Longer than only 32% of all vipers anyone has measured.

32% of 362 species are smaller68% 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

34 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
2008

The animal itself

Limbs
None
Venomous
Yes
Fangs
At the front of the mouth
Longest recorded life
19years

Size

Length snout to vent · greatest recorded
535mm21 in

Lucchini et al. 2020, Feldman et al. 2016 (SVL and Total length, respectively), Espasandin et al. 2022 show SVLs of slightly below 150 to slightly above 500 (fig 1 b)

Length nose to tail · greatest recorded
700mm2 ft 4 in

snakes only in this source

Hatchling length · snout to vent
150mm6 in
Body mass · greatestcomputed
119.9g4.2 oz

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

How it lives

Diet
Carnivorous

mainly herps and mammals (mostly rodents), few invertebrates and fewer birds, with juveniles eating mostly amphibians and reptiles and adults mostly mammals (Espasandin et al. 2022, Table 1)

How it hunts
Sit and wait

Sit (Feldman 2015)

Active
Diurnal

Feldman 2015

Where it lives
Terrestrial

imputed value from O'Shea 2018

Habitat
Forest
Biome
Temperate Broadleaf & Mixed Forests
Active season · months of the year
9months
Region
Palearctic
Mainland or island
Mainland
Highest it lives · above sea level
1900m

0-1900 (O'Shea 2018, Espasandin et al. 2022)

Range size
84,787km²

Breeding

Reproduction
Viviparous

Feldman et al. 2015

Sex decided by
Genes, ZW/ZZ
Average clutch
10eggs
Eggs or young per clutch
2–10eggs

3-10 (Mallow et al. 2003), 2-10 (O'Shea 2018)

Clutches in a year
1per year

Naming and history

Suborder
Serpentes
Infraorder
Alethinophidia
Subspecies
Vipera seoanei seoanei LATASTE 1879 Vipera seoanei cantabrica BRAÑA & BAS 1983
Described by
Lataste
Moved to another genus · since it was first described
No
Described in
1879
Type locality
Spain

Keeping one

2 ft 4 in × 14 in × 20.5 in(70 × 35 × 53 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 2 ft 4 in (700 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 Portugese 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.

14kJ per day

Worked out for an animal of 120 g, the heaviest recorded for Portugese 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 · 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 · 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
  • 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
  • Colour on the back
  • Pattern on the back
  • Pupil
  • Population trend
  • Red List criteria
  • Density · lowest recorded
  • Density · highest recorded
  • Home range · largest recorded
  • Active in
  • Lowest it lives · above sea level

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). Vipera seoanei. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/vipera-seoanei

@misc{vipera_seoanei_2026,
  title  = {Vipera seoanei},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/vipera-seoanei}
}

Sources

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