Trimeresurus macrops - Info & care

Cryptelytrops macrops, (Kramer, 1977)

Note: we @ hetterrarium.com do not advise nor want to stimulate anyone to purchase or keep venomous snakes. There are many potential risks and there are just as much if not more non-venomous snakes that are just as satisfying to keep without the risk and responsibility towards yourself and bystanders that comes with keeping venomous snakes. It takes many years of extensive experience with many facets of the snake/reptile hobby before one is ready, if ready at all for the responsibility to properly take care and keep safe of these snakes. Remember that anyone is different, also in their reaction to venom. So even a potential non-life threatening venomous snake can cause mayor heath issues, loss of limb, kidney functions or your life when your body reacts badly to the venom injected.

Like many Asian Crotalids this species has had some taxonomical changes. It was first officially described by Kramer in 1977 under the genus Trimeresurus (macrops) with the type locality Bangkok, Thailand. In 2004 it was revised, together with a lot of the arboreal (green) Trimeresurus by Malhorta & Thorn, placing it under the name Cryptelytrops. It took some time but after some years this name was widely accepted. In 2011 (David) it was suggested that this and many other sp. where placed back again under the genus Trimeresurus. Still most articles are referring to this sp. as Cryptelytrops macrops.

General appearance:  This small pitviper will reach a length of 50 till 71cm. With males being obviously smaller and more slender as the females. In many ways they look a lot like the other green Asian pitvipers such as the well-known C. albolabris and C. insularis. The bodycolor is a bright green. They have a red line running over their tail and males have a light (sometimes bluish) line running from beneath the eye along the first row of dorsal scales. The eye is a dirty yellow or light brown. The eyes are bigger compared to other snakes of the genus and the head is more stout/round, where those of the C. albolabris is more an elongated oval shape. The nasal scale and first subralabial of the C. macrops is fused, whilst those of the other Cryptelytrops sp are always separated.

General behaviour:  Like most arboreal Asian pitvipers C. macrops is mostly active during the twilight period and evening. They are ambush hunters and will perch themselves on a branch usually several metres above the ground. Here they will feed on mostly small vertebrates such as lizards, small birds and arboreal rodents. By day they will hide between the foliage, 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.

Natural range and habitat:  The type locality for this snake is Bangkok, Thailand. It also occurs in northern and northwest Thailand. With some unconfirmed reports of them being found in the western parts of Thailand. And in central and southern Laos and the north of Cambodia. It is found up to 600meters above sea-level. They prefer humid, well vegetates (semi)forests, bushes and bamboo forests, often close to a water source. Sometimes they are found in agricultural areas. Although in much smaller densities and as they look a lot like some other common green pitvipers accurate documentation is not present.

Previously the described range also included mostly hill/mountain ranges in Vietnam and central and southern Cambodia. After a revision of this taxon. These parts of their range where described to the newly described (Malhorta, 2011) Cryptelytrops rubeus (recognized by its red eyes) and Cryptelytrops cardamomensis.

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.

Cryptelytrops macrops don’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 1x0.6x1 (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 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 in 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 pregnant female. But will also suffice on the long term. Change the substrate regularly and spotclean when needed. Heating can be done via a baskingspot which also creates a natural light-cycle. Daytime temperatures should range from 24C till 27C. With a baskingspot (which is not commonly used) of 30/32C. During the night temperatures may drop depending on the season till 17-20C. The keeper could choose to use a nightlight for additional nocturnal heating and easy monitoring during the night. Mist almost daily to increase the humidity (70/80% day / 90% night) and so the animals can drink. Like many arboreal reptiles Cryptelytrops macrops 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. If u use a Exo-terra or Zoomed terrarium we would advise to cover a part 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 do not cover all.

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 Cryptelytrops 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 C. macrops 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 Cryptelytrops. 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. If we do need to inform you about the possible negatives, it 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 C. macrops as many pitvipers is a life bearing 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 small vertebrates such as lizards, frogs and small birds and arboreal rodents. In a captive situation however these snakes will thrive well on a diet of small mice. They easily accept defrosted dead prey. Young Cryptelytrops 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. Adult mouse are often big enough for fully adult macrops females. As males tend to stay smaller a sub-adult mouse is often a good preyitem for these.

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 does 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 you 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 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.

Breeding and captive propagation:  Cryptelytrops macrops is an ovoviviparous snake. Young usually measure 12-15cm at birth and shed within the next 24 hours. They look exactly like the adults. Keep in mind a female can fertilize more than a single litter from a single pairing, so ones a male has been introduced always keep a good observation on a possible pregnancy. The very small slender babies can crawl thru small holes and cracks and it has happened they escaped via ventilation holes or via the gap between sliding doors. So always have a well secured cage. If you use a terrarium with sliding doors, make sure they slide in a profile on all sides, so not only top and bottom to keep the window in place but also on the sides. Add a silicon strip between the 2 sliding windows to eliminate the gap. 

Venom:  The venom of the Cryptelytrops (Trimeresurus) macrops mainly consists out of heamotoxins and pro/anti coagulants. Studied bite incidents showed a clear effects on the fibrinolytic system and caused coagulation problems. Bites in the first stages cause redness, bleeding from the bitewound, irritation, swelling, pain, bruising, more pain, headache, nausea, stomach pain and cramps resulting in diarrhea and vomiting. Long term effect can be tissue damage and even loss of (part of) a limb, caused by the swelling and disrupted blood supply as well as tissue damage caused by the venom. All bites should be considered possible live threatening and should be takes serious. Always inform medical services and make sure you have a bite protocol per species ready with all the needed information in case of a bite.

As we mentioned we do not want to promote the keeping of any venomous snakes. There are a lot of potential risks towards yourself and bystanders and it takes a big sense of responsibility and a sufficient base of experience. We do recognize that there is a select group of serious well experienced keepers who can safely keep and enjoy these wonderful snakes.