Trimeresurus venustus - Info & care

Trimeresurus venustus. (Vogel, 1991)

This is without much doubt probably one of the more striking Asian pitvipers. That and the small size makes these one of the more popular species when it comes to keeping arboreal Asian pitvipers. We have had several years of success keeping and breeding this species and would like to share our experience keeping these wonderful snakes.

Of cource we must not forget these are venomous snakes and even do they may not be as potent as a cobra or mamba, still we cannot forget that they can cause serious injuries or worse, the way our body reacts to this venom can differ.

General appearance:  Trimeresurus venustus has a ‘typical’ body-type like the other arboreal pitvipers. They are slender snakes, very agile and have a head clearly distinct from the neck/body. The head is relatively short and round compared to the arboreal pitvipers from for instance the Parias genus or T. puniceus complex, this is well seen when you look from above. They have relatively big eyes, most often yellow/gold in colour.  The bodycolor is a clear green, with red/purple bands. These bands run along the back and fade into irregular spots on the dorsals. Also on the head there is an obvious but irregular pattern of these coloured markings. The ventrals have a lighter green colour, the dorsal and ventral colour is accentuated by the scales bordering these, all marked in white. Males also have a white line below the eye, a form of sexual dimorphism also seen with other Trimeresurus species. The males of this species also seem to be a bit brighter and have a blueish taint. Average size of this species is between 50cm and 70cm. Males are obviously smaller and more slender then the females.

General behaviour:  Like most arboreal Asian pitvipers T. venustus is mostly active during the twilight period and evening. They are perfect ambush hunters and will perch themselves on a branch usually close to the ground, hanging above a trail often used by small animals. Here they will feed on mostly small vertebrates such as lizards, small birds and arboreal rodents. By day they will hide between the foliage just several meters above the ground, relying on their great camouflage. When disturbed they will take on a classical S threat display, sometimes opening their mouth and wagging their tail around. They will not hesitate to strike and bite when an attacker comes to close. At night they are also often found traveling on the ground to a different ‘hunting-ground’ but in general their territory is relatively small.

Natural range and habitat:  Trimeresurus venustus has a relatively small range in the Southern part of Thailand. But in this range they seem to be widespread and common. The preferred habitat are humid, well vegetated tropical forests. Humidity is almost always high in these regions and there is a lot of precipitation. By day they stay hidden a few meters above the ground, normally between 1.5-3 meters. By night they move closer to the ground to sit and wait for prey to pass by. Sometimes they are also found in peoples garden or plantations, but numbers are a lot smaller here. They can be found several animals in a small habitat but all seem to have their own small territory.

Captive requirements:  Keep in mind. These are venomous snakes and venomous snakes already have a bad reputation and many think it should not be allowed at all to keep these in captivity by the general population. So a escaped snake is not acceptable! Not only can it cause a potential risk to the snake, you or worse, a bystander. A media hype about a escaped pet dog eating, human killing tyrant of a snake, Is probably not the best advertisement for our hobby.

This species doesn’t get very big and come from humid forests. So this species thrives well in a relatively small well planted terrarium. That being said a well planted terrarium does provide these wonderfully camouflaged snakes with lots of hiding opportunities. Take this in account when setting up the terrarium. Make sure you can always see the snake before opening the terrarium. As these are not very active snakes a terrarium that is a minimum of 0.8x0.6x1 (lxdxh) of their total length should be sufficient. The Exo-terra and Zoomed glass terrariums of 45x45x60 / 60x45x60 or bigger are a good option for a single specimen or pair of this species. We advise these and similar enclosures a lot for smaller (arboreal) venomous snakes because they lock well and lighting and heating is placed outside the enclosure. Not only does this look good, it also gives you easy access to these components without having to take the snake out and also your snake can not wrap around a lighting or heating fixture. Creating damage to the materials or themselves. For safety reasons and as this is not a ‘social’ species we always advice to keep a single specimen per terrarium. Preventing you need to divide your attention between more venomous snakes in a single enclosure. It also helps with a proper individual observation on health, feeding etc.

In a more basic setup, several branches for climbing, a waterbowl, a substrate of reptibark, cocohusk or similar and some artificial plants for decoration and hiding would be sufficient. This setup can be used only for new additions, quarantine or for instance a carrying female. But will also suffice on the long term. Change the substrate regularly and spotclean when needed. For lighting we normally use a T5 or T8 fluorescent daylight tube between 11.5 and 13 hours a day. Daytime temperatures should range from 25C till 27C. With a baskingspot (which is not commonly used by the snake) of 30/32C during some hours of the day is advised. During the night temperatures may drop depending on the season till 20-24C. The keeper could choose to use a nightlight for additional nocturnal heating and easy monitoring during the night. Misting as needed to increase the humidity (70/80% day / 90% night) and so the animals can drink. Like many arboreal reptiles Trimeresurus venustus rarely drinks from a waterbowl with stagnate water somewhere on the ground. Instead they rely on waterdrops on leaves, branches and their body left during and after it has rained for hydration. So regular misting makes sure they get plenty to drink. Misting shortly before the lights turn of and the snakes get active is the best moment to do so, as this is the period in nature the humidity rises. If u use a Exo-terra or Zoomed terrarium we would advise to cover 50% of the mesh top with a (plex)glass sheet. To reduce the amount of ventilation and help maintaining the higher humidity. Still, a well ventilated terrarium is essential for a healthy environment and snake, so cover as less as possible while providing the temperature and humidity requirements needed.

This all being said and having described a pretty basic husbandry, in which this snake will probably do fine, like many articles on this page we keep coming back to the more natural or even bio-active setup. Like many Asian pitvipers this species, due to its size and requirements lends itself very well for a more natural setup. The thick layer of substrate, small arthropods and live plants have a lot of positive results on the maintenance and humidity requirements. You can find an extended article about natural and bioactive setups in our ‘basics’ library section. But in this article we will describe the basics if you choose for a more natural setup for your Trimeresurus sp.

To start a bioactive setup a thick layer of substrate is needed. In this layer your plants will grow roots, the small arthropods will live and most of the waste and water will end up in this layer. Start with a drainage layer. This can be (clay) hydro balls or a thick filtration matt. Lay a thin sheet of anti-root cloth over this layer so you prevent the substrate coming in contact with this drainage layer. The substrate in this case can best consist out of cocopeat earth, turf of forest earth mixed with bark, leaves and moss. Make sure u use a thick layer of minimal 7/10cm. For a more natural look you can cover the substrate with dried leaves. Then decorate the enclosure with branches and vines so the snakes can climb and lay perched on many different heights and places in the enclosure. Make sure the branches and twigs are of many different widths. Bamboo is very smooth so will not be used a lot for climbing but does add a lot to a ‘Asian’ natural setup. Then add your live plants, to your snake nor to most keepers it doesn’t matter which plants u use. As long as their thrive and grow in the conditions needed for your snake. But to keep true to the Asian distribution of the pitviper Asian plants like Ficus benjamina, Ficus binnendijkii, Epipremnum sp, Scindapsus sp, Hoya sp, many Asplenium and some orchids can be used. All these wild plants do not only look very natural and create an ever changing environment in you small terrarium. But will also aid in keeping a higher humidity, provide your pitviper with many more hiding and climbing opportunities and will absorb waste ending up in the substrate. Therefor small Arthropods like springtails, worms, woodlice and similar small invertebrates are also a great attribute to this natural setup. These small creatures will feed on the waste produced by the snake and eat possible fungus or moulds. Keeping the enclosure clean without the need for any big maintenance.

We have a lot of great things to say about these types of setups as they have many positives. But we do need to inform you about the possible negatives, one would be that a small well camouflaged snake can hide well in a setup like this. As we are talking about a venomous snake in this article, observation of the snake without the need to open your cage is needed and you must always have eyes on the snake before opening the terrarium. Also parasites such as mites are not easily found or eradicated in a setup like this. So only place well settled animals in these setups and always quarantine any new additions in a more basic setup. Keep in mind this species is a Ovoviviparous snake. Having to locate a unknown amount of 15cm long green baby snakes in an well vegetated terrarium can be challenging, let alone be a safety issue.

Diet:  In the wild these snakes have a varied diet consisting of mostly frogs, followed by small (arboreal) rodents, birds, and sometimes lizards. In a captive situation however these snakes will thrive well on a diet of small mice. They easily accept defrosted dead prey. Young Trimeresurus can be fed with pinky mouse (parts) every 7 days. Juveniles and semi-adults can be fed every 10-14 days with a mid-sized prey. Sub-adult mouse are often big enough for fully adult T. venustus females. As males tend to stay smaller a springer mouse is often a good preyitem for these. Don’t be surprised if the males are stubborn feeders during some (mating) periods. This is normal and should not cause any problems for a healthy specimen.

It would be advised to feed with dead prey from a long tong or forceps. Ether pre-killed or defrosted (not in water because of vitamin debridement). Not only does this decrease any potential suffering to the rodent whilst the venom takes its effect. It also prevents you having to deal with an agitated venomous pitviper and a scared jumpy rodent in the same confined space when your snake decides it has no interest and the rodent needs to be recouped from the terrarium.

Young pitvipers including those of this species are known to feed mostly on small lizards and frogs when young. Therefor sometimes it can be a challenge to start them feeding on small mouse(parts) right away. Feeding them with a live day old pinky mouse will often trigger a feeding response. One could also tease the young snake by tapping the snake on its tail or body (not on the head) with the dead prey. They absolutely hate this and will often strike, ones they strike and bite they will often hold on. If this happens stay very still and hope the mouse in the mouth of the snake may result in a swallowing reaction. Often these small tricks will help. If not, scenting the prey item with a lizard or frog may help and make sure the food item is warm (not hot) so it gives of a clear heat signal. Feeding in de evening or by night gives a much better response.