All Angles Creatures
Squamata · BoidaeEntry 7,924 of 21,572
Yellow Anaconda, Eunectes notaeus

Reptilia · Squamata

Eunectes notaeusCope, 1862

Yellow Anaconda

Photograph placed in the public domain, CC0, via iNaturalist

A day-active, meat-eating snake from the Neotropic region, reaching 450 cm nose to tail.

Reptilia › Squamata › Boidae › Eunectes

Grows to
4500mm
greatest recorded
Eats
Carnivorous
Active
Diurnal
Lives up to
23.6years
Body length across Boidae

Longer than 97% of all boas anyone has measured.

97% of 63 species are smaller3% larger
109 mmthe whole family, smallest to largest6,700 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 109 to 6,700 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

38 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
2020
Population trend
Stable

The animal itself

Limbs
None
Venomous
No
Longest recorded life
23.6years

Stark et al. 2020

Body temp in the wild · mean, when active
22°C

body temperature of active animals in nature

Size

Length snout to vent · greatest recorded
2680mm8 ft 10 in

4000 mm total length (Feldman et al. 2016), max 4.5 m (Murphy 2020), Cabral et al. 2022 (max Total length 2550 mm, Max SVL: 2180 mm), max total length 192 and 301 cm for males and females, respectively, 60 females 1315-2680 mm, mean 1760 mm SVL, 37 males, 1290-2025, mean 1537 mm SVL (Tarkhnishvili et al. 2022), Reed 2005 (max TL 4.3 m), Williams and Vera 2023 TL over 4 m, 30 kg, neonates 55-60 cm), Pizzatto and Marques 2007 (female SVL: 2500, 2255 (N = 2), males 1816.5 ± 214.3 range 1515-2161, N = 8)

Length snout to vent · adult female mean
2377mm7 ft 10 in
Length nose to tail · greatest recorded
4500mm14 ft 9 in

snakes only in this source

Hatchling length · nose to tail
575mm22.5 in
Body mass · greatestcomputed
10,387g23 lb

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

Body mass at hatchingmeasured
53.7g1.9 oz

How it lives

Diet
Carnivorous

fish, birds and mammals (Sabaliauskas et al. 2023)

How it hunts
Mixed

Rahhal et al. 2023

Active
Diurnal

Williams and Vera 2023 see also Sabaliauskas et al. 2023

Where it lives
Semi-aquatic

"fossorial (leaf litter, termite mounds), > 50% digging" (Gearty et al. 2021), Aquatic (Cabral et al. 2022, Williams and Vera 2023, Sabaliauskas et al. 2023)

Habitat
Grassland, Savanna, Wetlands
Biome
Tropical & Subtropical Grasslands, Savannas & Shrublands
Region
Neotropic
Mainland or island
Mainland
Elevation · above sea level
80–250m

80-150 (O'Shea 2018), max 250 (Reed 2005), 132 (Sabaliauskas et al. 2023)

Range size
1,187,588km²

Breeding

Reproduction
Viviparous

Feldman et al. 2015

Average clutch
25eggs
Eggs or young per clutch
4–40eggs

mean 13 (Meiri et al. 2019), 10-40 (O'Shea 2018), max 30 (Reed 2005), 4-37 (Williams and Vera 2023), 13 (Pizzatto and Marques 2007; n = 1)

Mean clutch
13eggs
Clutches in a year
1per year
Clutches a year
0.33–0.5per year
First breeds at
48–84months

Naming and history

Suborder
Serpentes
Infraorder
Alethinophidia
Subspecies
No
Described by
Cope
Moved to another genus · since it was first described
No
Described in
1862
Type locality
Paraguay

Keeping one

14 ft 9 in × 7 ft 5 in × 11 ft 1 in(450 × 225 × 338 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 14 ft 9 in (4500 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 Anaconda. 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.

729kJ per day

Worked out for an animal of 10,387 g, the heaviest recorded for Yellow Anaconda — 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 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
  • — Largest juvenile · snout to vent
  • — Largest juvenile · shell length
  • — 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
  • — 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
  • — Fangs
  • — Colour on the back
  • — Pattern on the back
  • — Pupil
  • — 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 Boidae

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). Eunectes notaeus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/eunectes-notaeus

@misc{eunectes_notaeus_2026,
  title  = {Eunectes notaeus},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/eunectes-notaeus}
}

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.