Sri Lankan Green Pit Viper (Craspedocephalus trigonocephalus)

Sri Lankan Green Pit Viper (Craspedocephalus trigonocephalus) Care Sheet

The Sri Lankan Green Pit Viper (Craspedocephalus trigonocephalus) is a striking arboreal pit viper endemic to Sri Lanka. Older literature and captive records may list the species as Trimeresurus trigonocephalus.

It occurs through much of Sri Lanka outside the most arid regions and highest elevations, with particularly strong associations with wet-zone rainforest, riparian vegetation, grassland margins and cultivated areas such as tea and other plantations. Recent field research confirms that the species actively selects particular microhabitats and frequently uses filtered sunlight, dense vegetation and elevated branches.

Adults are typically green with darker markings and a comparatively robust build for an arboreal pit viper. They are primarily sit-and-wait predators and spend considerable periods resting or ambushing from vegetation.

The species is venomous and medically significant. Published clinical studies document human envenomation following bites.

It is suitable only for appropriately experienced specialist venomous-reptile keepers with secure accommodation, emergency procedures and all legally required permissions.

This care sheet provides comprehensive husbandry guidance. It is not a venomous-snake handling or restraint manual.

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

Quick Facts

Scientific name: Craspedocephalus trigonocephalus

Older scientific name: Trimeresurus trigonocephalus

Common names: Sri Lankan Green Pit Viper, Sri Lankan Pit Viper, Green Pit Viper

Family: Viperidae

Subfamily: Crotalinae

Native range: Sri Lanka only

Natural habitat: Rainforest, wet forest, riparian vegetation, grassland margins, dense shrub vegetation and some plantations

Lifestyle: Primarily arboreal

Activity: Primarily crepuscular/nocturnal with documented daytime basking

Adult size: Commonly around 24–36 in (60–90 cm); adults average around 30 in (75 cm), although exceptional individuals approaching 4 ft (1.2 m) have been reported

Build: Moderately robust for an arboreal pit viper

Lifespan: Plan for approximately 15–20 years of specialist care; robust species-specific longevity data remain limited

Experience level: Specialist venomous keepers only

Venomous: Yes — medically significant envenomation possible

Adult enclosure: Approximately 3 × 2 × 3 ft (90 × 60 × 90 cm) or larger for one adult

Warm basking/perch area: Approximately 27–29°C (81–84°F)

General daytime temperature: Approximately 23–27°C (73–81°F)

Cool retreat: Approximately 21–23°C (70–73°F)

Night: Approximately 20–23°C (68–73°F)

Humidity: Approximately 70–85%, with natural fluctuations, good ventilation and surface drying

Water: Fresh water continuously available plus drinking droplets after misting

Lighting: Approximately 11–12 hours daytime illumination

UVB: Low-level UVB may be provided as part of comprehensive modern husbandry

Target UVI: Approximately 0.5–1.0 at an accessible illuminated perch with extensive shade available

Diet: Appropriately sized whole vertebrate prey

Housing: Individual housing recommended

Reproduction: Viviparous — live-bearing

Quarantine: Approximately 90 days minimum is a sensible starting point

Important Venomous Species Warning

The Sri Lankan Green Pit Viper is a venomous snake capable of medically significant envenomation.

A suspected bite requires immediate medical assessment.

The fact that severe or fatal outcomes are less commonly reported than with some larger Asian vipers must never be interpreted as meaning that a bite is harmless.

Before acquisition, a prospective keeper should already have:

  • Appropriate specialist venomous-reptile experience
  • Secure purpose-built accommodation
  • Secondary containment
  • Effective escape prevention
  • Written emergency procedures
  • Appropriate veterinary arrangements
  • Knowledge of appropriate emergency medical facilities
  • An accidental-escape plan
  • A plan should the primary keeper become incapacitated
  • Appropriate legal permissions where required
  • A responsible backup person who knows what species are present and how to summon appropriate assistance

The animal should never be acquired before these arrangements are established.

Species Overview

The Sri Lankan Green Pit Viper is endemic to Sri Lanka.

It occurs through several climatic zones but is particularly associated with wetter habitats. Field research in Sri Lanka has recorded the species in forest, riparian and open habitats, with a particularly high encounter rate around densely vegetated riparian habitat.

Habitats include:

  • Lowland rainforest
  • Wet-zone forest
  • Riparian vegetation
  • Dense grassland margins
  • Shrub vegetation
  • Forest edges
  • Tea plantations
  • Coffee plantations
  • Cocoa plantations
  • Cardamom plantations

The species is strongly arboreal and commonly uses trees and shrubs.

Captive accommodation should therefore prioritise:

USABLE HEIGHT + STABLE PERCHES + DENSE COVER + HUMIDITY + VENTILATION + THERMAL CHOICE.

Natural Behaviour

Sri Lankan Green Pit Vipers are predominantly ambush predators.

Recent field research found ambushing to be a major component of observed behaviour. Animals also showed preferences for particular branch positions and filtered sunlight, and basking was documented during daylight hours.

This is important for captive husbandry.

The species should not be treated simply as a nocturnal snake requiring a permanently dim enclosure.

Instead, provide:

  • Bright daytime illumination
  • Filtered-light areas
  • Low-level UVB where used
  • Warm elevated positions
  • Dense shade
  • Complete retreat areas

The animal can then choose its preferred exposure.

Adult Size & Lifespan

Adult size commonly falls around:

24–36 in (60–90 cm).

Published clinical literature describes an average adult length of approximately:

30 in (75 cm)

with specimens around:

4 ft (1.2 m)

reported.

Females generally become:

  • Larger
  • More robust
  • Heavier-bodied

than males.

Although species-specific captive longevity information is limited, prospective keepers should plan for potentially:

15–20 years

of specialist care rather than regarding this as a short-term commitment.

Enclosure

For one adult Sri Lankan Green Pit Viper, approximately:

3 × 2 × 3 ft

(approximately 90 × 60 × 90 cm)

should be considered a practical starting point.

A particularly large adult benefits from:

3 × 2 × 4 ft

(approximately 90 × 60 × 120 cm)

or larger where safe management permits.

The enclosure should provide meaningful:

  • Height
  • Width
  • Branch complexity
  • Visual cover

rather than simply empty internal volume.

Why Height Matters

This is a genuinely arboreal snake.

A low terrestrial enclosure does not provide adequate behavioural choice.

Provide usable levels:

LOW → MID-LEVEL → HIGH

with several interconnected routes.

The animal should be able to move between:

  • Warmer and cooler areas
  • Bright and shaded areas
  • Exposed and concealed resting positions

without always descending to the floor.

Security

The enclosure must be:

  • Robust
  • Escape-resistant
  • Lockable
  • Resistant to accidental opening
  • Appropriately identified
  • Located within a secure dedicated room or facility

Inspect:

  • Door gaps
  • Sliding-door tracks
  • Ventilation openings
  • Cable ports
  • Hinges
  • Locks
  • Drainage openings
  • Service ports

Juveniles require particularly careful attention because extremely small openings can become escape routes.

Secondary Containment

The primary enclosure should exist within:

A SECURE SECONDARY ROOM OR FACILITY.

The primary enclosure should not be the sole physical barrier between a venomous snake and an uncontrolled area.

The surrounding room should:

  • Prevent unauthorised access
  • Reduce potential escape routes
  • Allow controlled visual assessment
  • Form part of the escape-response system

Routine Husbandry Design

The enclosure should minimise unnecessary close interaction during routine maintenance.

Routine requirements include:

  • Changing water
  • Spot cleaning
  • Checking temperatures
  • Checking humidity
  • Inspecting equipment
  • Maintaining plants and furnishings
  • Visual health assessment

Where specialist enclosure design permits, secure retreat or divided sections can improve safety.

The objective is:

MINIMAL DIRECT EXPOSURE DURING ROUTINE CARE.

Juvenile Enclosures

Juveniles require smaller accommodation scaled appropriately to their body size.

Security standards remain identical.

Neonatal and juvenile pit vipers are venomous.

Provide:

  • Fine but stable branches
  • Several perch levels
  • Dense foliage
  • Appropriate thermal gradient
  • Appropriate humidity
  • Excellent ventilation
  • Fresh water
  • Absolute escape prevention

Temperature & Heating

Sri Lankan Green Pit Vipers inhabit tropical environments but should still be offered a genuine thermal gradient.

Warm Perch/Basking Area

Approximately:

27–29°C (81–84°F)

General Daytime Temperature

Approximately:

23–27°C (73–81°F)

Cool Retreat

Approximately:

21–23°C (70–73°F)

Night

Approximately:

20–23°C (68–73°F)

Basking Behaviour

Although frequently described as nocturnal, field observations have documented daytime basking.

One recent wet-zone study found individuals commonly using filtered sunlight, with basking recorded particularly during morning and midday observations.

A captive animal should therefore have access to a modest warm illuminated perch.

This should be:

AN OPTION — NOT THE TEMPERATURE OF THE ENTIRE ENCLOSURE.

Avoid Overheating

Do not maintain the whole enclosure around:

29–30°C or higher.

The snake must be able to retreat into substantially cooler areas.

A tropical species can still overheat if deprived of behavioural thermoregulation.

Vertical Temperature Gradient

In a tall enclosure, temperature naturally varies with height.

Upper branches may be warmer than:

  • Mid-level branches
  • Lower branches
  • Floor-level retreats

Measure temperature where the animal actually sits.

Heating Equipment

Suitable options can include:

  • Secure overhead radiant heating
  • Low-output radiant heat panels
  • Controlled room heating
  • Appropriately protected ceramic heating

All heat sources should be:

  • Thermostatically controlled
  • Securely installed
  • Protected from animal contact
  • Suitable for humid conditions

Avoid:

  • Hot rocks
  • Exposed heating elements
  • Uncontrolled heaters

Temperature Monitoring

Use reliable digital thermometers.

Monitor:

  • Warm elevated perch
  • General mid-level temperature
  • Cool area
  • Night-time minimum

An infrared thermometer is useful for checking branch surface temperatures.

Remember:

THERMOSTAT SETTING ≠ ACTUAL ENCLOSURE TEMPERATURE.

Humidity

Maintain approximately:

70–85% relative humidity

with normal daily fluctuations.

The species’ wet-zone habitat receives substantial rainfall; research habitat in Sri Lanka’s wet zone experiences more than 2,500 mm of mean annual rainfall without a clearly defined dry season.

However, this does not mean a captive enclosure should remain permanently soaked.

Humidity Cycling

A useful pattern is:

MIST → HUMIDITY RISES → SURFACES GRADUALLY DRY → HUMIDITY FALLS → REPEAT AS REQUIRED.

Temporary peaks above 85% after misting are not inherently problematic when ventilation is excellent.

The important distinction is between:

HIGH AIR HUMIDITY

and:

CONSTANTLY WET SURFACES.

Ventilation

Good ventilation is essential.

High humidity combined with stagnant air can contribute to:

  • Respiratory disease
  • Dermatitis
  • Bacterial proliferation
  • Fungal growth
  • Mould

Aim for:

HUMID + FRESH AIR

rather than:

SEALED + WET + STAGNANT.

Misting

Light misting can:

  • Increase humidity temporarily
  • Create drinking droplets
  • Simulate rainfall
  • Encourage natural drinking behaviour

Mist:

  • Leaves
  • Branches
  • Selected enclosure surfaces

and allow them to dry partially between misting events.

Water & Hydration

Fresh clean drinking water should remain continuously available.

Use a stable water bowl that:

  • Cannot easily overturn
  • Is easy to disinfect
  • Can be serviced safely

Arboreal pit vipers may also drink droplets from:

  • Leaves
  • Branches
  • Enclosure surfaces

after misting.

Provide both opportunities.

MISTING DOES NOT REPLACE A PERMANENT CLEAN WATER SOURCE.

Substrate

Suitable substrate options include:

  • Tropical soil mixtures
  • Coco-based substrate
  • Orchid bark
  • Cypress-type mulch
  • Leaf litter
  • Appropriate combinations

The substrate should:

  • Buffer humidity
  • Drain effectively
  • Remain relatively low-dust
  • Allow exposed surfaces to dry
  • Be easy to spot-clean

Substrate Depth

Approximately:

2–4 in (5–10 cm)

is useful for many naturalistic setups.

Deeper substrate can be used in properly designed planted enclosures.

Drainage

Because regular misting may be required, drainage is important.

Water should not accumulate indefinitely beneath the substrate.

A drainage layer can be useful in:

  • Planted enclosures
  • Bioactive enclosures
  • Frequently misted systems

Drainage itself still requires inspection and maintenance.

Furnishings

Branch structure is one of the most important components of the enclosure.

Provide:

  • Horizontal branches
  • Diagonal branches
  • Branch forks
  • Vines
  • Cork
  • Dense foliage
  • Visual barriers
  • Secure retreat areas

Recent field observations found animals using different positions along branches, reinforcing the value of providing substantial, usable branch networks rather than isolated perches.

Branch Diameter

Provide multiple branch diameters.

Do not furnish the enclosure exclusively with thin twigs.

Branches should include diameters capable of supporting:

  • Comfortable resting coils
  • Stable ambush positions
  • Normal locomotion

Branch Orientation

Horizontal and gently diagonal branches are particularly useful.

Create connected routes between:

HIGH → MID → LOW

and:

BRIGHT → SHADED → CONCEALED.

This allows the animal to make meaningful environmental choices.

Branch Stability

Every branch must be securely fixed.

Branches must not:

  • Rotate
  • Collapse
  • Shift unexpectedly
  • Create pinch points

Test all structural furnishings before introducing the snake.

Visual Cover

Dense foliage is highly beneficial.

Provide:

  • Exposed resting positions
  • Partially covered positions
  • Dense concealment

This allows the snake to control its own visual exposure.

Live Plants

Suitable live tropical plants may be used where practical.

They can provide:

  • Visual cover
  • Drinking surfaces
  • Shade
  • Humidity buffering
  • Environmental complexity

Plants must be:

  • Non-toxic
  • Pesticide-free
  • Securely planted
  • Compatible with safe enclosure servicing

A naturalistic enclosure must never compromise security.

Environmental Enrichment

Useful enrichment can include:

  • Multiple climbing routes
  • Different perch diameters
  • Different elevations
  • Dense and open vegetation
  • Leaf cover
  • Naturalistic light gradients

For a venomous species, enrichment must remain compatible with safe observation and routine maintenance.

Lighting

Provide a clear day/night cycle.

Approximately:

11–12 hours daytime illumination

is appropriate.

Bright visible daytime illumination is particularly worthwhile because wild animals have been documented using filtered sunlight and basking.

A daylight LED can provide:

  • Circadian cues
  • Bright visible illumination
  • Plant support
  • Distinct light/shade zones

The enclosure should become properly dark at night.

Avoid visible:

  • Red
  • Blue
  • Purple

night lamps.

UVB

The Sri Lankan Green Pit Viper should not be treated as a high-UVI basking reptile.

However, its documented use of filtered sunlight makes access to appropriately low-level UVB a reasonable component of comprehensive modern husbandry.

The principle is:

LOW-LEVEL UVB + FILTERED-LIGHT OPPORTUNITY + EXTENSIVE SHADE + COMPLETE UV RETREAT.

Target UVI

A practical target is approximately:

UVI 0.5–1.0

at an accessible illuminated perch.

Elsewhere provide:

LOWER UV → DENSE SHADE → COMPLETE UV RETREAT.

Practical UVB Equipment Guidance

A:

LOW-OUTPUT LINEAR UVB SYSTEM

is the most practical approach.

The exact lamp required depends upon:

  • Lamp model
  • Reflector
  • Distance
  • Mesh
  • Enclosure height
  • Perch position
  • Lamp age

Do not choose UVB simply according to a percentage printed on the packaging.

The objective is:

UVI 0.5–1.0 AT THE ACTUAL ACCESSIBLE PERCH.

Understanding UVB Distance

Remember:

CLOSER = GENERALLY MORE UV

FARTHER AWAY = GENERALLY LESS UV

MESH = USUALLY LESS UV

This is especially important for arboreal reptiles.

A branch close to the enclosure roof can receive dramatically more UV than the floor.

UV Gradient

A useful arrangement is:

ILLUMINATED PERCH: Approximately UVI 0.5–1.0

PARTLY SHADED PERCHES: Lower UV

DENSE FOLIAGE: Very low UV

COMPLETE RETREAT: Approaching UVI 0

What This Means in Practice

Do not attempt to illuminate the entire enclosure equally with UVB.

Instead, create one gentle UV zone over part of the branch network.

The snake should be able to:

  • Sit beneath low-level UVB
  • Move partly into shade
  • Move into dense shade
  • Avoid UVB completely

without being forced to leave suitable temperature or security.

UV Meter

A suitable UV Index meter provides the most reliable method of checking actual exposure.

Measure:

AT THE HEIGHT OF THE SNAKE’S PERCHES.

Do not base an arboreal setup on a reading taken only at floor level.

If You Do Not Have a UV Meter

Use:

  • A reputable low-output linear UVB system
  • Manufacturer’s current distance guidance
  • Correct reflector
  • Mesh guidance
  • Generous shaded areas

Do not compensate for uncertainty by installing an unnecessarily powerful lamp.

Heat, UVB & Visible Light

These perform different functions:

HEATING SYSTEM = TEMPERATURE

UVB SYSTEM = ULTRAVIOLET

DAYLIGHT LED = VISIBLE LIGHT

One does not automatically replace another.

Feeding

Sri Lankan Green Pit Vipers are sit-and-wait predators.

Natural prey includes:

  • Lizards
  • Frogs
  • Small mammals
  • Birds

Their arboreal ambush behaviour is well documented.

Captive-bred animals can generally be maintained on appropriately sized whole vertebrate prey.

Frozen-Thawed Prey

Where accepted:

APPROPRIATELY PREPARED FROZEN-THAWED PREY

is preferable to routine live vertebrate feeding.

Live rodents can seriously injure snakes.

Whole-Prey Nutrition

Whole prey supplies:

  • Muscle
  • Bone
  • Organs
  • Fat
  • Micronutrients

Pieces of meat are not an appropriate substitute for a nutritionally complete whole-prey diet.

Prey Size

Avoid oversized meals.

A modest visible swelling is sufficient.

Excessively large prey can:

  • Increase regurgitation risk
  • Promote obesity
  • Reduce mobility
  • Make normal arboreal perching more difficult

Feeding Frequency

Juveniles

Approximately:

every 7 days

depending upon prey size, growth and body condition.

Subadults

Approximately:

every 7–14 days

depending upon prey size.

Adults

Approximately:

every 14–21 days

is a reasonable starting point for many healthy adults, adjusted according to:

  • Prey size
  • Sex
  • Activity
  • Reproductive condition
  • Body condition

Do not feed according to appetite alone.

Body Condition

Maintain an:

ATHLETIC, MUSCULAR ARBOREAL BODY CONDITION.

The animal should not become excessively rounded or bulky.

Females naturally become more robust than males.

Obesity

Obesity can contribute to:

  • Reduced climbing ability
  • Abnormal resting posture
  • Metabolic disease
  • Reproductive problems
  • Reduced long-term health

Avoid power-feeding juveniles.

Feeding Safety

Food should never be offered directly by hand.

Routine feeding arrangements should minimise unnecessary close exposure to the animal.

This care sheet deliberately does not provide procedural venomous-snake manipulation instructions.

Behaviour & Temperament

Normal behaviour can include:

  • Long periods coiled on vegetation
  • Ambushing from branches
  • Moving primarily during lower-light periods
  • Changing perch according to temperature
  • Daytime basking
  • Resting in filtered light
  • Moving into dense cover

Field research recorded ambushing as a particularly prominent behaviour.

A stationary animal should never be interpreted as harmless or incapable of rapid movement.

Camouflage

Green colouration combined with dense foliage can make the snake surprisingly difficult to locate.

Before routine enclosure servicing begins, the keeper must establish the animal’s location.

Naturalistic enclosure design should not make safe observation impossible.

Defensive Behaviour

An agitated animal may:

  • Reorient toward movement
  • Tighten its body
  • Adopt a strike posture
  • Vibrate its tail
  • Strike

Individual behaviour varies.

Apparently calm behaviour does not reduce the medical significance of the snake.

Handling

Sri Lankan Green Pit Vipers should not be casually handled.

This care sheet deliberately does not provide instructions for:

  • Free-handling
  • Manual restraint
  • Physical manipulation

Practical venomous-snake competence requires appropriate specialist training and experience.

Cohabitation

Individual housing is recommended.

This allows accurate monitoring of:

  • Feeding
  • Weight
  • Faeces
  • Shedding
  • Health
  • Behaviour

and simplifies routine husbandry.

Controlled breeding introductions are different from permanent cohabitation.

Cleaning & Routine Care

Regularly monitor:

  • Drinking water
  • Faeces
  • Urates
  • Shed skin
  • Branch stability
  • Plant condition
  • Substrate moisture
  • Drainage
  • Humidity
  • Ventilation
  • Temperatures
  • Lighting
  • Locks
  • Parasites
  • General behaviour

Spot-clean contamination promptly.

Bioactive Enclosures

A bioactive system can be appropriate for experienced keepers where security remains uncompromised.

However:

BIOACTIVE DOES NOT MEAN MAINTENANCE-FREE.

Continue monitoring:

  • Waste
  • Drainage
  • Substrate condition
  • Mould
  • Plant health
  • Pest species
  • Water quality

The ability to safely locate and assess the snake must be retained.

Quarantine

All newly acquired animals should undergo strict quarantine.

Approximately:

90 DAYS MINIMUM

is a sensible starting point.

Longer may be appropriate for:

  • Imported animals
  • Animals of uncertain provenance
  • Animals showing clinical abnormalities
  • Animals with suspected parasite exposure

Use dedicated husbandry equipment where practical.

Quarantine Setup

A relatively simple secure quarantine enclosure makes observation easier.

Useful features include:

  • Easily inspected substrate
  • Simple secure branches
  • Easily cleaned furnishings
  • Dedicated water bowl
  • Dedicated equipment

This helps reveal:

  • Mites
  • Abnormal faeces
  • Regurgitation
  • Blood
  • Discharge
  • Parasites

Quarantine Monitoring

Record:

  • Body weight
  • Feeding
  • Defecation
  • Urates
  • Drinking
  • Shedding
  • Respiration
  • Skin condition
  • Mouth condition
  • Perching behaviour

Veterinary examination and parasite screening should be considered where appropriate.

Common Health Concerns

Respiratory Disease

Possible signs include:

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

Contributing factors can include:

  • Inappropriate temperatures
  • Poor ventilation
  • Constantly saturated conditions

Stomatitis

Possible signs include:

  • Oral swelling
  • Discharge
  • Damaged oral tissue
  • Abnormal mouth position
  • Reduced feeding

Veterinary assessment is required.

Skin Disease

Constant wetness can contribute to:

  • Dermatitis
  • Scale inflammation
  • Bacterial infection
  • Fungal problems

Maintain humidity without keeping the animal continuously wet.

Parasites

Watch for:

  • Mites
  • Weight loss
  • Abnormal faeces
  • Poor condition
  • Reduced appetite

Imported animals require particularly careful assessment.

Dysecdysis

Poor shedding may be associated with:

  • Dehydration
  • Inappropriate humidity
  • Parasites
  • Underlying illness

Obesity

Prevent through:

  • Appropriate prey size
  • Appropriate feeding frequency
  • Regular weight monitoring

Regurgitation

Possible causes include:

  • Excessive prey size
  • Incorrect temperatures
  • Disturbance
  • Underlying disease

Repeated regurgitation requires veterinary assessment.

Falls & Perch Injuries

Unstable branches can contribute to injury.

All structural furnishings should remain secure.

Signs of Good Health

A healthy Sri Lankan Green Pit Viper should generally display:

  • Clear eyes outside shedding
  • Clean nostrils
  • Quiet respiration
  • Intact scales
  • Strong controlled perching
  • Appropriate muscular body condition
  • Normal tongue-flicking
  • Appropriate feeding response
  • Normal faeces
  • Complete healthy sheds

When to Seek Veterinary Advice

Seek appropriately experienced reptile veterinary care for:

  • Respiratory symptoms
  • Oral or nasal discharge
  • Significant unexplained weight loss
  • Persistent abnormal food refusal
  • Repeated regurgitation
  • Skin lesions
  • Burns
  • Abnormal swelling
  • Persistent abnormal faeces
  • Significant injury
  • Reproductive problems
  • Major unexplained behavioural changes

Veterinary Planning

Suitable veterinary support should be identified before acquisition.

Not every reptile veterinarian is prepared or equipped to work with venomous snakes.

The veterinary practice should know:

  • Exact species
  • Venomous status
  • Approximate size
  • Reason for presentation

before transport occurs.

Never unexpectedly arrive at a veterinary practice carrying a venomous snake.

Emergency Planning

A written emergency plan should exist before the animal enters the facility.

It should include:

  • Exact species present
  • Relevant emergency medical arrangements
  • Appropriate emergency contacts
  • A plan should the primary keeper become incapacitated
  • Details of suitably competent backup assistance

Responsible people associated with the premises should know that venomous reptiles are present and know how to summon appropriate assistance without entering the secure reptile area.

Any suspected Sri Lankan Green Pit Viper bite requires:

IMMEDIATE EMERGENCY MEDICAL ASSESSMENT.

Published clinical literature confirms medically significant human envenomation from this species.

Do not rely upon improvised home treatment.

Escape Planning

A written escape plan should exist.

Because this is an arboreal species, an escaped animal may seek:

  • Shelving
  • Plants
  • Curtains
  • Pipework
  • Furniture
  • Lighting structures
  • Elevated fixtures

The secure room should therefore be designed with arboreal escape behaviour in mind.

People without appropriate specialist competence should not attempt recovery.

Prevention through secure containment remains the priority.

Breeding

Sri Lankan Green Pit Vipers are:

VIVIPAROUS — LIVE-BEARING.

Females give birth to fully formed young.

Breeding should only be attempted by appropriately experienced venomous-reptile keepers with:

  • Mature healthy adults
  • Secure facilities
  • Appropriate emergency planning
  • Separate accommodation for offspring
  • Legal compliance
  • Documented provenance
  • A realistic long-term plan for every neonate

Reproductive Conditioning

Breeding condition should be developed through:

  • Excellent long-term nutrition
  • Appropriate body condition
  • Seasonal environmental variation
  • Correct temperature
  • Humidity cycling
  • Appropriate photoperiod

Extreme cooling is inappropriate for this tropical species.

Gravid Females

A gravid female may:

  • Become visibly broader
  • Alter feeding behaviour
  • Change perch preference
  • Seek warmer positions
  • Reduce activity later in gestation

Provide excellent:

  • Hydration
  • Thermal choice
  • Stable perches
  • Security
  • Ventilation

Neonates

Newborn Sri Lankan Green Pit Vipers are venomous.

Each requires:

  • Secure individual accommodation
  • Fine but stable perches
  • Appropriate temperature
  • Suitable humidity
  • Excellent ventilation
  • Fresh water
  • Appropriate prey
  • Extremely careful escape prevention

Every opening should be assessed against neonatal body size.

Neonate Feeding

Young animals may naturally take small:

  • Frogs
  • Lizards
  • Mammals
  • Other vertebrate prey

Captive-bred animals may establish successfully on appropriately sized rodent prey.

The objective is:

RELIABLE FEEDING + STEADY GROWTH + HEALTHY BODY CONDITION

rather than rapid growth.

Conservation & Provenance

The Sri Lankan Green Pit Viper is endemic to Sri Lanka and is listed as a protected species under Sri Lankan wildlife legislation according to Sri Lankan fauna records.

This makes documented legal provenance particularly important.

Prospective keepers should strongly favour:

ESTABLISHED CAPTIVE-BRED ANIMALS WITH TRACEABLE LEGAL ORIGIN.

Never assume that an animal being offered commercially automatically has appropriate provenance.

Legal Considerations — Republic of Ireland

The Republic of Ireland is not governed by the UK’s Dangerous Wild Animals Act.

A British Dangerous Wild Animals licence should therefore not be presented as a Republic of Ireland requirement for keeping this species.

Anyone acquiring, keeping, breeding, transporting, importing, exporting or transferring a venomous reptile in the Republic of Ireland should verify all legislation and requirements applicable at the time.

Relevant considerations can include:

  • Animal health and welfare legislation
  • Import/export requirements
  • Wildlife-trade restrictions
  • Transport requirements
  • Public-safety responsibilities
  • Property, tenancy and insurance restrictions
  • Legal provenance of protected foreign wildlife

The species’ protected status in its country of origin makes provenance documentation particularly important.

Legal Considerations — Northern Ireland

Northern Ireland has its own dangerous wild animal licensing legislation.

Anyone proposing to keep a venomous viper should verify the current licensing requirements with the appropriate Northern Ireland authority before acquisition.

Legal Considerations — Great Britain

Viperidae, including pit vipers, are included within the Dangerous Wild Animals licensing framework applicable in Great Britain.

Anyone intending to keep this species in England, Scotland or Wales should verify the current requirements with the relevant local authority before acquisition.

Important Jurisdiction Distinction

For readers in Ireland and the UK:

REPUBLIC OF IRELAND ≠ NORTHERN IRELAND ≠ GREAT BRITAIN

Their legal frameworks are not interchangeable.

The Dangerous Wild Animals legislation applicable in Great Britain does not apply in the Republic of Ireland.

Compliance in one jurisdiction does not automatically establish compliance in another.

Responsible Ownership Checklist

Before acquiring a Sri Lankan Green Pit Viper, ensure you can provide:

  • Appropriate specialist venomous-reptile experience
  • Documented legal provenance
  • Secure dedicated reptile facility
  • Lockable escape-resistant enclosure
  • Secondary containment
  • Approximately 3 × 2 × 3 ft or larger adult accommodation
  • Meaningful usable height
  • Stable interconnected branches
  • Multiple perch diameters
  • Dense visual cover
  • Bright and shaded areas
  • Correct thermal gradient
  • Limited warm perch
  • Cooler retreat
  • Appropriate humidity cycling
  • Excellent ventilation
  • Fresh drinking water
  • Drinking droplets
  • Suitable substrate
  • Effective drainage
  • Clear day/night lighting
  • Optional low-level UVB
  • Complete UV retreat
  • Appropriate whole-prey diet
  • Controlled body condition
  • Strict quarantine
  • Specialist veterinary arrangements
  • Written medical emergency plan
  • Written escape plan
  • Responsible backup arrangements
  • Secure transport arrangements
  • Correct legal permissions
  • Long-term specialist care

Common Husbandry Mistakes

Keeping an arboreal species in a low enclosure
Provide meaningful usable height.

Only providing one branch
Create an interconnected branch network.

Using only thin twigs
Provide several perch diameters.

Unstable branches
Every structural perch must be securely anchored.

Sparse visual cover
Dense foliage provides essential behavioural choice.

Keeping the enclosure permanently dim
Wild animals use filtered sunlight and have documented basking behaviour.

Making the entire enclosure hot
Provide a limited warm zone and genuine cool retreat.

Maintaining the enclosure permanently wet
High humidity does not mean constant saturation.

Poor ventilation
Humid stagnant conditions increase health risks.

No drainage
Regular misting requires effective water management.

Assuming misting replaces a water bowl
Fresh clean water should remain available.

Using excessive UVB
Only low-level exposure is appropriate.

Ignoring perch height when setting UVB
An arboreal snake can sit much closer to the lamp than the enclosure floor.

Overfeeding
Maintain an athletic body condition.

Offering oversized prey
Use modest appropriately sized meals.

Assuming a stationary snake is harmless
Ambush predators can strike rapidly.

Casual handling
This is a venomous species.

No secondary containment
The enclosure should exist within a secure surrounding facility.

No medical emergency plan
Planning must exist before acquisition.

No escape plan
An escaped arboreal snake may seek elevated structures.

No veterinary plan
Identify appropriate veterinary support beforehand.

Ignoring provenance
This is a Sri Lankan endemic protected in its native country.

Assuming UK DWA legislation applies in the Republic of Ireland
It does not.

Husbandry Summary

Adult size: Commonly approximately 24–36 in (60–90 cm); exceptional specimens may approach 4 ft (1.2 m)

Adult enclosure: Approximately 3 × 2 × 3 ft (90 × 60 × 90 cm) or larger

Lifestyle: Arboreal

Activity: Primarily crepuscular/nocturnal with documented daytime basking

Warm perch: Approximately 27–29°C (81–84°F)

General daytime temperature: Approximately 23–27°C (73–81°F)

Cool retreat: Approximately 21–23°C (70–73°F)

Night: Approximately 20–23°C (68–73°F)

Humidity: Approximately 70–85%

Ventilation: Essential

Water: Fresh drinking water continuously available

Misting: Useful for drinking droplets and humidity cycling

Substrate: Moisture-buffering tropical substrate with effective drainage

Lighting: Approximately 11–12 hours daytime illumination

UVB: Optional low-level linear UVB

Target UVI: Approximately 0.5–1.0 at an accessible perch with complete shade available

Diet: Appropriately sized whole vertebrate prey

Adult feeding: Approximately every 14–21 days as a starting point, adjusted according to prey size and body condition

Housing: Individual housing recommended

Handling: Specialist venomous-reptile management only

Reproduction: Live-bearing

Neonates: Venomous

Quarantine: Approximately 90 days minimum as a sensible starting point

Experience: Specialist/expert

Captive-bred: Strongly preferred

Provenance: Particularly important due to the species’ endemic and protected status in Sri Lanka

Practical UVB Summary

For the Sri Lankan Green Pit Viper, comprehensive modern husbandry may include:

LOW-LEVEL UVB + FILTERED-LIGHT OPPORTUNITY + EXTENSIVE SHADE + COMPLETE UV RETREAT

A suitable low-output linear UVB system can provide approximately:

UVI 0.5–1.0

at an accessible illuminated perch.

The exact equipment required depends upon:

  • Lamp model
  • Reflector
  • Distance
  • Mesh
  • Enclosure construction
  • Perch height

Remember:

CLOSER = GENERALLY MORE UV

FARTHER AWAY = GENERALLY LESS UV

MESH = USUALLY LESS UV

and:

HEAT = TEMPERATURE

UVB = ULTRAVIOLET

DAYLIGHT LED = VISIBLE LIGHT

These perform separate functions.

Wild Sri Lankan Green Pit Vipers have been documented using filtered sunlight and engaging in basking behaviour, supporting the provision of genuine light choice rather than a uniformly dark captive environment.

Measure UV at the actual branch heights available to the animal.

The snake must always be able to choose complete shade.

Important Information

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

The Sri Lankan Green Pit Viper (Craspedocephalus trigonocephalus) is a venomous snake capable of medically significant envenomation. It is suitable only for appropriately experienced specialist keepers with secure facilities, emergency procedures and all legally required permissions.

This care sheet deliberately does not provide step-by-step instructions for handling, restraint or physical manipulation of venomous snakes.

The Dangerous Wild Animals legislation applicable in Great Britain does not apply in the Republic of Ireland. Northern Ireland has separate dangerous wild animal legislation. Always verify the current requirements for the jurisdiction in which the animal will actually be kept.

The species is endemic to Sri Lanka and recorded as protected under Sri Lankan wildlife legislation. Captive-bred animals with documented legal provenance should be strongly preferred.

If you have concerns about an animal’s health or care, consult a suitably experienced reptile veterinarian who is prepared and equipped to work with venomous reptiles.

Information correct at the date of publication.

reptilecommunity.com | Revised: August 2026