Bolivian Anaconda (Eunectes beniensis)

Bolivian Anaconda (Eunectes beniensis) Care Sheet

The Bolivian Anaconda (Eunectes beniensis) is a large, powerful semi-aquatic boa native to Bolivia, particularly the seasonally flooded wetlands and river systems of the Beni region.

It was historically confused with other anacondas but is recognised as a distinct species. In captivity it remains considerably less common than the Green Anaconda (Eunectes murinus) or Yellow Anaconda (Eunectes notaeus).

Bolivian Anacondas are specialist animals. Their combination of adult size, muscular strength, aquatic behaviour, feeding response, water-management requirements and long lifespan makes them unsuitable for inexperienced keepers.

Good husbandry requires purpose-built accommodation providing both a substantial aquatic area and usable terrestrial space. The enclosure must allow the snake to fully submerge, thermoregulate, rest securely and move normally while remaining practical to clean and maintain.

A juvenile should never be acquired without a realistic plan for its adult accommodation.

Captive-bred animals of documented provenance should be strongly preferred.

Quick Facts

Scientific name: Eunectes beniensis
Common name: Bolivian Anaconda, Beni Anaconda
Family: Boidae
Native range: Bolivia, particularly the Beni region
Lifestyle: Semi-aquatic
Activity: Often crepuscular or nocturnal, although activity can occur throughout the day
Adult size: Commonly around 7–10 ft (2.1–3 m), with females generally larger and some individuals potentially exceeding this
Lifespan: Potentially 20+ years with appropriate care
Experience level: Advanced
Diet: Carnivorous
Adult enclosure: Purpose-built; approximately 8 × 4 × 4 ft (2.4 × 1.2 × 1.2 m) should be considered a practical starting point for many adults, with substantially larger accommodation for large females
Warm resting area: Approximately 88–90°F (31–32°C)
Warm ambient: Approximately 82–86°F (28–30°C)
Cool area: Approximately 75–79°F (24–26°C)
Night temperature: Approximately 72–77°F (22–25°C)
Water temperature: Approximately 77–82°F (25–28°C)
Humidity: Approximately 70–85% with good ventilation
UVB: Low-level UVB can be incorporated into comprehensive modern husbandry
Target illuminated UVI: Approximately 1–2 with extensive lower-UV and shaded areas
Water: Large enough for complete comfortable submersion
Handling: Experienced large-constrictor procedures required
Social housing: Individual housing recommended
Reproduction: Viviparous — live-bearing

Species Overview

Bolivian Anacondas are heavily built members of the genus Eunectes.

Their natural habitat is strongly associated with:

  • Wetlands
  • Floodplains
  • Marshes
  • Rivers
  • Streams
  • Seasonally flooded grasslands
  • Dense waterside vegetation

Much of the Beni region experiences pronounced seasonal flooding.

Anacondas are extremely well adapted to these environments.

The eyes and nostrils are positioned relatively high on the head, allowing the snake to remain largely submerged while still:

  • Seeing
  • Breathing
  • Monitoring its surroundings

Their muscular bodies make them powerful swimmers.

On land they can appear comparatively cumbersome, but they should not be considered inactive animals.

In captivity, they must be treated as:

large semi-aquatic constrictors

rather than terrestrial snakes provided with an oversized water bowl.

Adult Size & Lifespan

Bolivian Anacondas are large snakes.

Adults are often approximately:

7–10 ft (2.1–3 m)

although reliable captive size information is more limited than for Green and Yellow Anacondas.

Females generally become:

  • Longer
  • Heavier
  • More robust

than males.

Some individuals may exceed the typical range.

Because captive information remains relatively limited, enclosure planning should be conservative.

Do not construct accommodation around the smallest reported adult size.

Body Condition

Anacondas are naturally robust snakes.

However, a naturally heavy body shape should not be confused with obesity.

A healthy animal should retain:

  • Strong muscular definition
  • Good movement
  • Appropriate body proportions

without excessive fat deposition.

Lifespan

Keepers should plan for:

20+ years

of care.

Exact maximum longevity is not as well documented as in some more established captive species, but this should be regarded as a long-term commitment potentially lasting decades.

Enclosure

Adult Bolivian Anacondas require large, robust, purpose-built accommodation.

For many adults, approximately:

8 × 4 × 4 ft
(approximately 2.4 × 1.2 × 1.2 m)

should be considered a practical starting point.

Large females may require approximately:

10 × 5 × 4 ft, 10 × 6 × 4 ft or larger.

Accommodation should ultimately be determined by the actual size and behaviour of the animal.

More space is strongly encouraged.

Why Purpose-Built?

The enclosure must simultaneously provide:

  • Substantial water volume
  • Dry terrestrial space
  • Thermal gradient
  • High humidity
  • Good ventilation
  • Secure access
  • Safe heating
  • Easy cleaning
  • Drainage
  • Structural strength

A conventional wooden vivarium with a large plastic water bowl is unlikely to provide adequate adult accommodation.

Juveniles

Juveniles can initially be maintained in smaller appropriately sized enclosures.

These should still provide:

  • Secure hides
  • Appropriate thermal gradient
  • Water large enough for meaningful soaking/submersion
  • Suitable humidity
  • Good ventilation

As the animal grows, accommodation should be upgraded before space becomes restrictive.

Do not deliberately keep a growing anaconda in a very small enclosure simply because it is easier to manage.

Aquatic Area

A substantial aquatic area is fundamental.

The snake should be able to:

fully submerge its entire body comfortably.

Ideally, it should also be able to:

  • Turn freely
  • Rest submerged
  • Move through the water
  • Enter and leave without difficulty

The aquatic area should form a meaningful proportion of the enclosure.

Depending upon design, approximately:

one-third to one-half of the usable floor area

may be devoted to water while still providing substantial dry land.

Water Depth

The pool should be deep enough for complete submersion.

However, enclosure design should allow the snake easy access to:

  • The surface
  • Resting points
  • Entry and exit areas

Avoid designs with:

  • Vertical slippery sides
  • Narrow trapping points
  • Unprotected plumbing
  • Difficult exits

Entering & Leaving the Water

Provide safe transitions using:

  • Sloped edges
  • Ramps
  • Steps
  • Submerged platforms

where necessary.

Large-bodied snakes should not repeatedly have to drag themselves over a high sharp pool edge.

Water Temperature

Maintain approximately:

77–82°F (25–28°C)

as a useful general target.

Water temperature should be monitored independently.

A large pool can remain substantially cooler than the surrounding enclosure air.

Water Heating

Where active water heating is necessary, heating equipment must be protected from the snake.

An adult anaconda can easily:

  • Crush aquarium heaters
  • Dislodge equipment
  • Damage cables
  • Move plumbing

Where possible, heating should be incorporated into:

  • A protected sump
  • External filtration system
  • Isolated water-heating system

rather than placing exposed glass or plastic heaters directly in the pool.

Filtration

Large semi-aquatic snakes produce substantial organic waste.

The aquatic system may be contaminated by:

  • Faeces
  • Urates
  • Shed skin
  • Substrate
  • Food debris

A high-capacity filtration system is strongly recommended.

A suitable system may incorporate:

  • Mechanical filtration
  • Biological filtration
  • Easily cleaned pre-filters
  • External pumps
  • Sump filtration

Equipment should be sized for:

the biological waste produced by a large snake

rather than simply the water volume.

Water Changes

Filtration does not eliminate water changes.

Routine maintenance may include:

  • Partial water changes
  • Filter cleaning
  • Removal of visible debris
  • Complete drainage when necessary
  • Periodic disinfection

Faecal contamination should be addressed promptly.

Water that appears clear is not necessarily clean.

Drainage

For permanent adult accommodation, built-in drainage is strongly recommended.

Large pools can contain hundreds of litres of water.

A proper drain makes:

  • Water changes
  • Cleaning
  • Disinfection
  • Emergency emptying

far more manageable.

Planning drainage during construction is considerably easier than retrofitting it later.

Temperature & Heating

Provide a thermal gradient.

Warm Resting Area

Approximately:

88–90°F (31–32°C)

Warm Ambient

Approximately:

82–86°F (28–30°C)

Cool Area

Approximately:

75–79°F (24–26°C)

Night Temperature

Approximately:

72–77°F (22–25°C)

is a sensible general nighttime range.

Avoid prolonged excessive cooling.

Heating Equipment

Large purpose-built enclosures may use:

  • Overhead radiant heat panels
  • Properly guarded ceramic heating
  • Other safe radiant heating systems
  • Controlled room heating in dedicated facilities

All equipment must be:

  • Secure
  • Thermostatically controlled
  • Protected from direct animal contact
  • Suitable for humid environments

Thermostats

All powerful heating equipment should be appropriately controlled.

However:

the thermostat setting is not the enclosure temperature.

Temperatures must still be physically measured.

Temperature Monitoring

Use several digital thermometers.

Monitor:

  • Warm-side air
  • Cool-side air
  • Warm resting surface
  • Water temperature

An infrared thermometer is useful for checking surfaces.

Large enclosures require multiple measurements.

Lighting & UVB

Bolivian Anacondas naturally occupy environments containing a mixture of:

  • Open water
  • Dense vegetation
  • Sunlit margins
  • Deep shade

They are not intense open-country basking reptiles.

Therefore, they should not be exposed to the high UVI levels appropriate for many desert lizards.

However, comprehensive modern husbandry can provide access to:

low-level UVB

while allowing extensive shade.

Target UVI

Aim approximately for:

UVI 1–2

in an accessible illuminated/resting area.

The snake should also have access to:

  • Areas below UVI 1
  • Deep shade
  • Complete UV shelter

The snake should choose its exposure.

What Is UVI?

UVI means Ultraviolet Index.

It tells us approximately how much biologically effective ultraviolet radiation actually reaches the animal.

This is much more useful than simply specifying a UVB percentage.

What UVB Do I Actually Need?

For a Bolivian Anaconda enclosure, use a:

quality linear UVB system capable of producing low-level UV exposure.

Depending upon:

  • Enclosure height
  • Lamp model
  • Reflector
  • Mounting position
  • Mesh
  • Distance

a relatively low-output system may be entirely adequate.

The target is:

approximately UVI 1–2 at an accessible illuminated area.

Do not automatically purchase a powerful desert UVB tube.

Why Doesn’t the Percentage Tell Me Everything?

A UVB tube may be labelled:

  • 2.5%
  • 5%
  • 6%
  • 7%

but that number does not tell you what reaches the snake.

Actual exposure depends upon:

  • Distance
  • Reflector
  • Mesh
  • Lamp age
  • Installation

Two enclosures using the same lamp can produce very different UVI levels.

Distance Matters

In simple terms:

Closer lamp = generally more UV

Farther away = generally less UV

Mesh between lamp and snake = usually less UV

This is why the mounting distance must match the exact equipment being used.

What Should I Ask for at an Expo or Reptile Shop?

If you’re unfamiliar with UVB equipment, ask for:

“A linear UVB system for a large semi-aquatic tropical snake, giving approximately UVI 1–2 in an accessible illuminated area with plenty of complete shade.”

Then determine the correct mounting distance for the exact system.

This is much more useful than simply asking for:

“an anaconda UVB bulb.”

UV Gradient

A useful arrangement is:

Illuminated area: UVI 1–2

Lower exposure: below UVI 1

Dense shade: approaching UVI 0

The whole enclosure does not require UVB coverage.

UV Meter

An appropriate UV Index meter is the best way to verify actual exposure.

Measurements should be taken approximately:

at the height of the snake’s body in the illuminated area.

If You Don’t Own a UV Meter

Use:

  • A reputable UVB system
  • Manufacturer’s current distance guidance
  • Correct mounting method
  • Guidance regarding mesh
  • Extensive shade

Do not guess by buying the strongest available lamp.

Bright Visible Lighting

A large tropical enclosure should have a clear daytime lighting cycle.

Daylight LED lighting can help provide:

  • Bright visible illumination
  • Day/night cues
  • Light and shade gradients
  • Support for suitable live planting

Remember:

HEATING SYSTEM = WARMTH

UVB SYSTEM = ULTRAVIOLET

DAYLIGHT LED = VISIBLE LIGHT

They perform different jobs.

Photoperiod

Approximately:

11–13 hours of daylight

is appropriate.

Around 12 hours provides a sensible tropical starting point.

The enclosure should become dark at night.

Avoid visible red, blue or purple night lamps.

Humidity, Hydration & Ventilation

Maintain approximately:

70–85% relative humidity

with normal fluctuations.

The aquatic area will naturally contribute considerable humidity.

However:

high humidity does not mean stagnant air.

Good ventilation is essential.

The goal is:

WARM + HUMID + VENTILATED

not:

WARM + WET + STAGNANT.

Poor ventilation combined with persistent wetness can contribute to:

  • Bacterial growth
  • Mould
  • Respiratory problems
  • Skin disease

Substrate & Furnishings

The terrestrial area should provide substrate that:

  • Retains some humidity
  • Provides traction
  • Is not abrasive
  • Can be cleaned effectively
  • Does not remain permanently waterlogged

Suitable options may include:

  • Cypress-type mulch
  • Orchid bark
  • Coco-based substrate
  • Appropriate soil-based mixtures

For extremely large individuals, purpose-built enclosures may incorporate durable washable surfaces in some areas while retaining naturalistic substrate zones.

Furnishings

Suitable furnishings include:

  • Large robust hides
  • Heavy logs
  • Visual barriers
  • Sturdy artificial vegetation
  • Appropriately protected live plants

Everything must be scaled to the adult snake.

Lightweight decorative furnishings will simply be moved or crushed.

Hides

Large snakes still require security.

Provide:

  • Substantial terrestrial retreat
  • Visual barriers
  • Areas away from direct observation

A hide must be large enough to use comfortably but should not create inaccessible spaces where safe husbandry becomes impossible.

Feeding & Supplementation

Bolivian Anacondas are carnivorous constrictors.

Wild anacondas consume a variety of vertebrate prey.

A captive diet can be based upon appropriately sized whole prey.

Depending upon snake size, suitable foods may include:

  • Rats
  • Guinea pigs
  • Rabbits
  • Appropriate poultry

Dietary variety can be useful.

Frozen-Thawed Prey

Where accepted:

appropriately prepared frozen-thawed prey is generally preferable to live vertebrate prey.

Live prey can inflict serious injuries.

Prey Size

Avoid routinely offering enormous prey.

The snake should display:

a moderate visible swelling after feeding

rather than extreme distension.

The ability to swallow an exceptionally large meal does not mean doing so routinely is healthy.

Feeding Frequency

Feeding frequency depends upon:

  • Age
  • Size
  • Meal size
  • Activity
  • Body condition

Juveniles

Approximately:

every 7–10 days

may be appropriate.

Subadults

Approximately:

every 10–14 days

may be appropriate.

Adults

Many adults can be maintained on suitable meals approximately:

every 2–3 weeks

or longer depending upon prey size and body condition.

These are guidelines, not rigid schedules.

Obesity

Obesity is a major risk in captive large constrictors.

Anacondas naturally have heavy bodies, making excessive condition easy to overlook.

Monitor:

  • Body shape
  • Muscle tone
  • Activity
  • Weight trends

Long-term obesity can contribute to:

  • Fatty liver disease
  • Cardiovascular strain
  • Reduced mobility
  • Reproductive problems
  • Reduced lifespan

Do not power-feed juveniles.

Healthy growth should be:

steady rather than maximised.

Feeding Safety

Large anacondas can have extremely strong feeding responses.

Before opening the enclosure:

  • Locate the snake’s head
  • Know the purpose of opening the enclosure
  • Have feeding equipment ready
  • Ensure the surrounding area is controlled

Use long feeding tongs.

Do not routinely hand-feed.

Consistent behavioural cues can help distinguish feeding from routine maintenance.

Handling & Temperament

Individual temperament varies.

Young anacondas may display:

  • Hissing
  • Striking
  • Biting
  • Musking
  • Rapid retreat into water

Captive-bred animals may become more predictable with calm management.

However:

a calm large constrictor remains an exceptionally powerful animal.

Large-Constrictor Handling

As the snake grows, handling should become a planned procedure.

Never allow a large constrictor to wrap freely around the:

  • Neck
  • Head
  • Chest

Maintain awareness of the snake’s:

  • Head
  • Body position
  • Tail
  • Surroundings

For substantial adults, more than one competent adult handler should be available when significant handling or restraint is required.

Handling Assistance

There is no universal rule based solely on snake length.

The number of handlers required depends upon:

  • Snake weight
  • Strength
  • Behaviour
  • Experience
  • Task being performed

The key principle is:

never place yourself in a situation where one person cannot safely control an emergency.

Children & Public Handling

Bolivian Anacondas are not appropriate snakes for casual public handling.

Large individuals should only be handled by competent adults familiar with large-constrictor safety.

Transport

Plan adult transport before it becomes necessary.

A large adult may require:

  • Heavy-duty secure container
  • Multiple handlers
  • Suitable vehicle
  • Temperature control
  • Pre-planned route
  • Veterinary coordination

Emergency transport should not be improvised.

Veterinary Planning

Before acquiring the species, identify a reptile veterinarian capable of treating:

large constrictors.

A clinic that treats reptiles may still lack:

  • Space
  • Staff
  • Equipment
  • Safe restraint facilities

for a large adult anaconda.

Cohabitation

Individual housing is recommended.

Permanent cohabitation can create:

  • Feeding accidents
  • Competition
  • Stress
  • Difficulty monitoring individuals
  • Difficulty identifying health problems

Temporary controlled introduction for breeding is different from permanent group housing.

Cleaning & Routine Care

Daily or frequent checks should include:

  • Water quality
  • Temperature
  • Humidity
  • Equipment function
  • Animal behaviour
  • Visible contamination

Remove:

  • Faeces
  • Urates
  • Shed skin
  • Uneaten food
  • Heavily contaminated substrate

promptly.

Water Maintenance

The aquatic system may require:

  • Filter servicing
  • Partial water changes
  • Complete drainage
  • Cleaning
  • Disinfection

depending upon contamination and system design.

Faecal contamination should be addressed promptly.

Biosecurity

Use dedicated husbandry equipment where practical.

Wash hands before and after handling reptiles or enclosure contents.

New animals should never share:

  • Water equipment
  • Cleaning tools
  • Enclosure furnishings

with established animals during quarantine.

Quarantine

New Bolivian Anacondas should undergo strict quarantine.

Approximately:

90 days minimum

is a sensible starting point.

Longer may be appropriate where:

  • Origin is uncertain
  • Parasites are identified
  • Health problems occur

Monitor:

  • Weight
  • Appetite
  • Faeces
  • Respiration
  • Skin
  • Shedding
  • Hydration
  • Behaviour

Veterinary examination and faecal parasite screening are strongly recommended.

Common Health Concerns

Respiratory Disease

Possible signs include:

  • Wheezing
  • Clicking
  • Nasal discharge
  • Excess oral mucus
  • Persistent abnormal open-mouth breathing

Seek veterinary attention promptly.

Skin Disease

Poor water quality or constantly wet contaminated surfaces can contribute to:

  • Dermatitis
  • Scale damage
  • Blister-like lesions
  • Bacterial infection

Parasites

Particularly relevant to animals of uncertain provenance.

Possible signs include:

  • Weight loss
  • Poor body condition
  • Reduced feeding
  • Abnormal faeces

Obesity

One of the most important preventable captive problems.

Monitor body condition rather than appetite alone.

Burns

Unsafe heating equipment can cause severe injuries.

All heating equipment must be:

  • Controlled
  • Protected
  • Secure

Mouth Disease

Seek veterinary attention for:

  • Oral swelling
  • Discharge
  • Damaged tissue
  • Persistent abnormal mouth opening

Regurgitation

Potential causes include:

  • Excessively large meals
  • Incorrect temperatures
  • Stress
  • Handling too soon after feeding
  • Disease

Repeated regurgitation requires veterinary investigation.

Signs of Good Health

A healthy Bolivian Anaconda should generally display:

  • Clear eyes
  • Clean nostrils
  • Quiet breathing
  • Strong coordinated movement
  • Smooth intact scales
  • Good muscle tone
  • Appropriate body condition
  • Normal feeding behaviour
  • Normal faeces
  • Healthy shedding

When to Seek Veterinary Advice

Consult a suitably experienced reptile veterinarian for:

  • Respiratory symptoms
  • Nasal or oral discharge
  • Significant unexplained weight loss
  • Severe lethargy
  • Repeated regurgitation
  • Persistent food refusal outside expected circumstances
  • Skin lesions
  • Burns
  • Abnormal swelling
  • Persistent abnormal faeces
  • Significant injuries
  • Reproductive problems
  • Major unexplained behavioural change

Breeding

Bolivian Anacondas are:

viviparous — live-bearing.

Females retain developing young internally and give birth to live offspring.

Breeding information is less extensive than for some other anaconda species, so breeding programmes should be approached conservatively and based on current species-specific information.

Breeding Condition

Only healthy mature animals in excellent condition should be bred.

Do not breed animals that are:

  • Underweight
  • Obese
  • Unwell
  • Recently acquired
  • Insufficiently mature

Females require excellent nutritional reserves because reproduction is energetically demanding.

Seasonal Cues

Reproductive behaviour may be influenced by seasonal changes in:

  • Temperature
  • Rainfall/humidity
  • Photoperiod
  • Feeding
  • Environmental conditions

Extreme cooling should not be used.

Courtship

Breeding introductions require close observation.

Provide sufficient space for animals to:

  • Move apart
  • Rest independently
  • Access thermal resources

Separate animals if significant aggression or stress occurs.

Gestation

Pregnant females may:

  • Become substantially heavier
  • Alter feeding behaviour
  • Change thermal preferences
  • Spend increased periods resting

Provide excellent:

  • Thermal choice
  • Water quality
  • Hydration
  • Security

Birth

Young are born:

fully formed and independent.

Because published reproductive information for E. beniensis is comparatively limited, keepers should avoid presenting one fixed litter size as universal.

Breeders should be prepared for:

multiple substantial live young

and have individual accommodation available before birth.

Neonatal Care

Newborns require:

  • Secure accommodation
  • Appropriate thermal gradient
  • Suitable humidity
  • Clean water
  • Secure hides
  • Appropriately sized whole prey

Individual housing allows accurate monitoring of:

  • Feeding
  • Weight
  • Shedding
  • Faeces
  • Health

Legal & Provenance Considerations

Bolivian Anacondas are uncommon in captivity.

Documented provenance is particularly important.

Keep available:

  • Breeder information
  • Purchase records
  • Parentage where known
  • Identification records
  • Relevant CITES/import/export documentation
  • Transfer records

Requirements concerning:

  • Keeping
  • Sale
  • Breeding
  • Transport
  • Import/export
  • Dangerous animals
  • Animal welfare

vary between jurisdictions.

Always check current legislation before acquisition or transfer.

Do not assume that availability for sale automatically means the species can legally be kept everywhere.

Responsible Ownership Checklist

Before acquiring a Bolivian Anaconda, ensure you can provide:

  • Purpose-built adult accommodation
  • Approximately 8 × 4 × 4 ft or larger depending upon adult size
  • Substantially larger accommodation for large females
  • Large aquatic area
  • Complete submersion
  • Safe pool access
  • Water temperature monitoring
  • Effective filtration
  • Drainage
  • Strong secure enclosure construction
  • Warm resting area
  • Thermal gradient
  • High humidity with good ventilation
  • Low-level appropriate UVB
  • Bright daytime illumination
  • Suitable whole-prey diet
  • Controlled feeding
  • Safe large-constrictor handling procedures
  • Additional competent handlers
  • Secure transport
  • Specialist veterinary access
  • Long-term financial commitment
  • Appropriate documentation

Common Husbandry Mistakes

Buying a juvenile without planning for the adult
Adult accommodation should be considered before acquisition.

Treating it as an ordinary terrestrial boa
This is a strongly semi-aquatic snake.

Providing only a large water bowl
Adults require meaningful aquatic accommodation.

Pool too small for complete submersion
The snake should be able to submerge comfortably.

Poor filtration
Large snakes contaminate water rapidly.

No drainage
Adult water management becomes extremely difficult.

Water too cold
Monitor water separately from air.

Heating the entire enclosure uniformly
Provide a genuine thermal gradient.

High humidity without ventilation
Humid does not mean stagnant.

No secure dry resting area
Semi-aquatic does not mean permanently aquatic.

Using intense desert-style UVB
Low-level UV exposure with extensive shade is more appropriate.

Choosing UVB only by percentage
Actual UVI at the animal matters.

No visible daytime lighting
Provide a clear day/night cycle.

Power-feeding juveniles
Fast growth is not automatically healthy growth.

Feeding excessively large prey
Use sensible meal sizes.

Routine live feeding
Live vertebrate prey can cause serious injury.

Handling a substantial adult alone
Use appropriate large-constrictor safety procedures.

Allowing uncontrolled wrapping around the neck or chest
Never permit dangerous positioning.

Assuming a calm snake is harmless
Temperament does not remove physical strength.

No veterinary plan
Confirm specialist veterinary access before acquisition.

Poor provenance records
Retain documentation for uncommon captive species.

Husbandry Summary

Adult enclosure: Approximately 8 × 4 × 4 ft (2.4 × 1.2 × 1.2 m) as a practical starting point for many adults; large females may require 10 × 5 × 4 ft, 10 × 6 × 4 ft or larger

Adult size: Commonly around 7–10 ft (2.1–3 m), with females generally larger

Lifestyle: Semi-aquatic

Warm resting area: Approximately 88–90°F (31–32°C)

Warm ambient: Approximately 82–86°F (28–30°C)

Cool area: Approximately 75–79°F (24–26°C)

Night: Approximately 72–77°F (22–25°C)

Water temperature: Approximately 77–82°F (25–28°C)

Humidity: Approximately 70–85% with good ventilation

Aquatic area: Large enough for complete comfortable submersion

Filtration: Strongly recommended

Drainage: Strongly recommended for permanent adult accommodation

UVB: Low-level linear UVB can be incorporated

Target UVI: Approximately 1–2 in an accessible illuminated area with extensive shade

Visible lighting: Clear daytime illumination with shaded areas

Diet: Appropriately sized whole vertebrate prey

Juvenile feeding: Approximately every 7–10 days depending upon prey size and condition

Adult feeding: Approximately every 2–3 weeks or longer depending upon meal size and body condition

Handling: Advanced large-constrictor procedures

Housing: Individual housing recommended

Reproduction: Live-bearing

Lifespan: Plan for 20+ years

Experience level: Advanced

Quarantine: Approximately 90 days minimum as a sensible starting point

Captive-bred: Strongly preferred

UVB — What Do I Actually Need to Buy?

For a Bolivian Anaconda, you do not need the intense UVB used for desert lizards.

The practical goal is:

low-level UV exposure with extensive shade.

Look for:

a quality linear UVB system capable of providing approximately UVI 1–2 in an accessible illuminated area.

Do not choose equipment simply because one tube has a higher UVB percentage than another.

The actual amount of UV reaching the snake depends upon:

  • Lamp model
  • Reflector
  • Distance
  • Mesh
  • Installation

Remember:

Closer lamp = generally more UV

Farther away = generally less UV

Mesh = usually reduces UV

If you are buying equipment at an expo or reptile shop and are unsure what to ask for, say:

“I need a linear UVB system for a large semi-aquatic tropical snake, providing around UVI 1–2 in an accessible area with plenty of complete shade.”

Then determine the correct mounting distance for the exact system.

The enclosure should provide:

UVI 1–2 → LOWER UV → SHADE → COMPLETE UV SHELTER.

Remember that UVB does not provide all of the animal’s lighting or heating requirements:

HEATING SYSTEM = WARMTH

UVB SYSTEM = ULTRAVIOLET

DAYLIGHT LED = BRIGHT VISIBLE LIGHT

These perform different jobs.

The aim is not to expose the entire enclosure to UVB.

The aim is:

to give the animal access to appropriate low-level UV when it chooses, while always allowing complete retreat from it.


IMPORTANT INFORMATION

This care sheet provides general husbandry guidance and does not replace species-specific research or veterinary advice. Individual requirements may vary.

Bolivian Anacondas are large, exceptionally powerful semi-aquatic constrictors requiring specialist accommodation, substantial water-management systems, safe handling procedures and considerable long-term resources. They are unsuitable for inexperienced keepers.

Because Eunectes beniensis is considerably less common in captivity than Green or Yellow Anacondas, keepers should retain detailed provenance and acquisition records and continue consulting current species-specific information as knowledge develops.

Always check current legislation and documentation requirements governing the acquisition, keeping, breeding, transport, sale and import/export of this species in your jurisdiction.

Captive-bred animals of documented provenance should be strongly preferred.

If you have concerns about an animal’s health or care, consult a suitably experienced exotic or reptile veterinarian. For large constrictors, confirm in advance that the veterinary practice has the facilities and staff required to manage the animal safely.

Information correct at the date of publication.

reptilecommunity.com | Revised: August 2026