Encyclopaedia
ReptileTerrestrialSemi-aquaticExpert
©AI Generated·Proprietary
Yellow Anaconda
Eunectes notaeus
The yellow anaconda is an immense semi-aquatic predator. It requires a colossal 240x120x120 cm industrial enclosure featuring a substantial heated water basin for soaking, high humidity, and a heavily reinforced structure.
Class:Squamata
Order:Squamata
Family:Boidae
Subfamily:Boinae
Genus:Eunectes
Species:Eunectes notaeus
Share
Check out Yellow Anaconda on Atlarium
Water Temperature
26 - 35 °C
Environment
Terrestrial / Semi-aquatic
Humidity
75 - 90 %
Day temperature
28 - 30 °C
Ambient temperature
28 °C
Night temperature
18 - 22 °C
Basking spot
32 - 34 °C
Adult size
400 cm
Minimum enclosure
>= 3,500 L
UVB
Low
Species description
Geographical Origin and Habitat: Eunectes notaeus is native to central South America, with populations concentrated in the river basins of Paraguay, Bolivia, southern Brazil, and northern Argentina. It primarily inhabits marshes, swamps, slow-moving rivers, and seasonally flooded savannas (such as the Pantanal). Being highly adapted to aquatic life, it spends most of its time submerged among floating vegetation waiting for prey.
Taxonomy and Genetics: Belongs to the family Boidae, subfamily Boinae, and the genus Eunectes. Commonly known as the yellow anaconda, it is distinguished from the larger green anaconda (Eunectes murinus) by its smaller size and distinctive color pattern. There are no recognized subspecies, but populations exhibit wide variation in dorsal spot patterns.
Behavior and Habits: It is a solitary reptile with strong crepuscular and nocturnal habits, though it may bask on riverbanks during the day. In captivity, it often displays a defensive and high-strung temperament, reacting quickly to perceived threats with strikes. It requires confident, experienced handling, preferably using reptile hooks, and is entirely unsuitable for beginners.
Morphology: It is a heavy and thick-bodied constrictor snake, with adult females reaching an average length of 3-4 meters (approx. 10-13 feet) and males typically smaller at 2-3 meters. The head is narrow and elongated, with eyes and nostrils positioned on top of the skull to allow breathing while submerged. The body is yellow or yellow-green with large black oval spots.
Care, breeding and tankmates
Terrarium Setup: Requires a custom, industrial-sized enclosure for adults, with minimum dimensions of 240x120x120 cm. The setup must include a solid terrestrial area with humidity-resistant substrate (like cypress mulch or coconut husk) and a large, heated, and filtered water tub (pool) covering at least 50% of the floor space, deep enough for complete submersion.
Lighting and Heating: Demands a precise temperature gradient in both terrestrial and aquatic zones. Ambient air temperature must range from 28-30 °C (82-86 °F) on the warm side, with a basking spot of 32-34 °C (90-93 °F) and a cool side of 24-26 °C (75-79 °F). Water should be kept at 25-27 °C (77-80 °F) using protected heaters. Low-output UVB (5%) is recommended.
Humidity and Hydration: Relative humidity must be kept high, between 70% and 80%, supported by the large water pool and daily automated misting. Hydration is achieved both through cutaneous absorption while soaking and by drinking directly from the pool. The pool water must be kept clean using a powerful external filtration system.
Feeding and Supplementation: An opportunistic predator. The diet should consist of size-appropriate thawed rats, quail, rabbits, and fish. Adults should be fed every 10-14 days. Regular vitamin supplementation is not required if feeding healthy, whole prey, but occasional calcium dusting is beneficial for growing juveniles.
Compatibility: Strictly solitary animal. Housing multiple specimens together is highly discouraged outside of monitored breeding introductions, as it causes extreme stress, aggression, and potential cannibalism. Any handling should be done with care, and a second person should be present when working with large adults for safety.
Health and Common Diseases: Due to its aquatic habits, it is prone to skin infections and scale rot if water hygiene or substrate cleanliness is neglected. Other common health issues include respiratory infections from improper temperatures, intestinal impaction from accidental substrate ingestion, and external parasites (snake mites).
Geographic Origin and Distribution
Eunectes notaeus is native to central South America, with populations concentrated in the river basins of Paraguay, Bolivia, southern Brazil, and northern Argentina. It primarily inhabits marshes, swamps, slow-moving rivers, and seasonally flooded savannas (such as the Pantanal). Being highly adapted to aquatic life, it spends most of its time submerged among floating vegetation waiting for prey.
Origin
Extra-Amazon South AmericaCentral America and Caribbean
Reptile profile
- Diet
- No verified data available
- Life expectancy
- No verified data available
- Adult size
- 400 cm
- Lifestyle/Microhabitat
- No verified data available
- Activity cycle
- No verified data available
- Sociality
- No verified data available
- Reproduction
- No verified data available
- Handling tolerance
- No verified data available
- Brumation
- No verified data available
- Molting
- No verified data available
The catalog's scalar value is 400 cm. The ReptTraits v1.2 source reports a maximum adult measurement of 400 cm for this species, recorded as total length (TL). These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
