Ovophis okinavensis - Info & care

Ovophis okinavensis, (Boulenger, 1892)

Note: we @hetterrarium 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.

Status:  Ovophis okinavensis are not listed by Cites. Nor are they seen as a species that is at theat. But Japan does not allow export of their wild fauna. So available animals must be captive bred.

General appearance:  Ovophis okinavensis has a typical build for an ambush hunter like all Ovophis are. The body is sturdy and relatively short. Males will get between 60-70cm. Where females can get up to 80cm and sometimes reach 100cm in length. Making this probably the biggest Ovophis sp currently known. The head is triangular shapes and strongly divided from the neck. The body colour can be ether a yellowish brown, light till dark brown or very grey with an almost black pattern. Along the body they have a pattern or dark saddles and on the sides the pattern consist of smaller blotches or thick lines that most often do not connect with the saddles on the back. Compared to these smooth scales of most Ovophis sp. this species has very rough keeled scales.

General behaviour:  Like most Ovophis this snake is primarily nocturnal. They are ambush hunters and will seek out a shelter where they hope a prey will pass. They are very well camouflaged in the terrain they hide. They are most active after it has rained. Most bites in their natural range happen when people step on these snakes. While walking thru the bush or working in fields. Caudal luring has been observed with these species. As also the known ‘constricting’ behaviour as seen with other Ovophis sp.

Natural range and habitat:  Ovophis okinavensis is endemic to a small part of Japan. They live on a few islands of the Ryukyu islands group that are positioned between the south of Japan and the north-west of Taiwan. The biggest island (group) these snakes inhabit is Okinawa, where the type locality comes from and they are found on the island group Amani. They are also found on some smaller islands surrounding these 2 main locations. These islands have a sub-tropical climate. There are 2 seasons on these islands. One is the cooler and dryer season with an average temperature of 16C (13-18C). A daylength of 10.5 hours with 4/5 hours of sunlight and the warm and wet season with a lot more rain, average temperatures of 28C (26-31) and a daylength of 13.5 hours with 8hours of sunlight. The habitat this species is found varies. They can be found in humid forests, mountainous lands with a lot of Cycas palms and rocks, woodlands, along streams and creeks and on cultivated lands used for pineapple and sugar cane production. Although these snakes are mostly nocturnal they can be found basking on rocks close to freshwater streams. Other venomous snakes that are found in the same region are the well-known Protobothrops flavoviridis, Protobothrops mucrosquamatus and Sinomicrurus japonicus boettgeri.

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 tyrants of a snake. Is probably not the best advertising for our hobby.

Young Ovophis okinavensis can be setup pretty sparse and simple. They do not require as high humidity as for instance the Ovophis tonkinensis and O. monticola. Although these snakes fit well and do best in a naturalistic (bio-active) setup we recommend a more simple setup for young animals to have a better control and easier maintenance. The setup for a young O. okinavensis can be a small terrarium or plastic, well secured and ventilated ‘shoe-box’. You can use ether a cocopeat mixed with moss or moist cypress mulch (Zoomed forest floor) as a substrate. Mist 4 times a week and make sure at least one half of the box is always very humid. Place a big waterbowl and use artificial or naturalistic hides.

Sub-adults and adults can be placed in a more natural terrarium. We very much like the Exo-terra glass terrariums because they have a secure lock , are well ventilated and lights can be placed outside the enclosure. An individual of this species needs an enclosure that is at least 90x45x45cm. But bigger enclosures will certainly be appreciated. These snakes almost never climb so a higher enclosure is not needed but will do wonders for a more natural decor. It is best to house no more than a single snake per terrarium. Not only because this is safer as you have just one snake to keep your focus on, but also because males will be very sexually active and will engage in territorial fights with other males. And constantly bother the females. If you want to house a pair together the enclosure needs to be bigger with plenty of space for the snakes to retreat and separate themselves from the other.

If you want to place the adults in a more natural setup it is best to use a drainage layer of clay hydro balls underneath your substrate. This will make sure water is drained from your substrate and prevents your substrate from getting to wet. This can especially occur in the summer season when the misting needs to be done frequently. As a substrate you can use a thick layer of cocopeat mixed with bark, leaves and moss. By adding small springtales and other atropods you will create a bio-active setup where a lot of the waste from the snakes will be eaten by these small invertebrates. They will also feed on any potential fungus or mould. Covering the top layer of your substrate with a layer of leaves will give a very natural look and the snakes love to hide between them. Use corkbark, logs, roots and branches to decorate the enclosure and for the animals to use as hides. Some sturdy plants can be added as decoration. Like cultivated Cycas palms, Epipremnum, Ferns and Ficus. We have observed males climbing on thick low hanging branches. Add some rocks to replicate a part of their natural habitat.

To simulate a natural cycle the enclosure needs to be illuminated with a fluorescent daylight tube. For 9.5 till 13 hours a day depending on the season. In the warmer seasons u can use a basking spot to enhance the overall air temperature of 25-28C and create a hotspot of 32C. In the cooler season a basking spot can be provided for a small amount of hours. During this cooler season the enclosure needs to be misted ones a week till 3 times a week. During the warmer seasons the misting will be increased to 5 till 6 times a week. A automatic misting system set on a timer will be of great use with the care of the species.

Diet:  In the wild the Ovophis okinavensis feeds on a great variety of prey. Small lizard and frogs, small mammals and sometimes a bird. They are true ambush predators and will use their tail to lure a prey (Caudal luring) while laying well camouflaged between the leave litter.

Of all Ovophis sp. young O. okinavensis are probably the easiest to get feeding on small pinky mouse while in their natural range the main diet consists of small frogs and lizards (like Takydromus). The young are big and don’t need a lot of stimulation to bite and hold on if tease feeding is applied. This snake can be kept healthy for a long time on a staple diet of small rodents and chicks. Prey that can be fed are mouse, small rats, chicks and for instance hamsters, gerbils and African softfurs. It would be advisable to always feed dead or pre-killed prey. Feed prey that are a maximum of 110% the width as the thickest part of the snake.

Feed young okinavensis every 7 days. Sub-adults and adults can be fed every 14 days till month. Remember these snakes are not as active and have a slow metabolism. Feed more frequently before the mating season. This stimulates mating activity and makes sure the female is on a healthy weight to reproduce. They will feed during both the cooler and warmer season. Males will often stop feeding during the mating season. The only reason for a female to go off food will be health issues or if they are close to giving birth.

Breeding and captive propagation:  Ovophis okinavensis is in basis oviviparous. In the basis this means the baby will develop in a egglike sack inside the mother. Who will incubate them in her body by seeking out the right conditions for development. Ones the young are fully developed the snake will ‘give birth’ to these eggs and which point the eggs will hatch directly. The difference with viviparous development is that the young do not have a placental connection to the mother but get their nutrition from the yolk in the egg sack. Just as in an actual egg that is laid by oviparous reptiles. But, the interesting part about the reproductive manner of the Okinawa habu Is the fact these snakes can also be somewhat oviparous. Meaning they will lay ‘eggs’ that need to develop further outside the mothers body before actually hatching. This can take just 24 hours, a few days till 21 days or more, with on average 4 till 9 days. These eggs do not have the same thick white leathery shell like most reptile eggs. But are thin, movable and often (semi)-transparent. Often the female will stay with the eggs during this short incubation period. Also the manner of reproduction may depend on the season and environmental conditions. So a single female can have a different manner of reproduction per reproductive year.

In captivity males will try to breed the female the whole year. But females are often only ready to breed during the spring after the cooler and dryer season when the temperatures and humidity are rising again. So it is advisable to only introduce the male during this season. There have been personal observations done by several hobbyist that it is advisable to use several males per female to stimulate breeding. But often a single male in the right season will give a good result. Males will court the female extensively by laying against and on top of her. Twitching and shocking his body and trying to lift her tail to gain access to her cloaca. If the female is ready she will relax and allow the male to insert one of his hemipenis. Ones you see a male laying in a opposite corner of the female after a lot of courting. Chances are the male has successfully mated. And it is best to separate him again. You can try several times. But always remove the male when the female shows signs she is gravid. Females will in general lay their eggs 3 till 4 months after a successful mating. They will often stop feeding 2 till 4 weeks before they lay their eggs in a hide. But during gestation their feeding response and thermoregulating activity will increase so make sure there is a proper basing spot available to her.

Venom:  Like most Ovophis sp. the venom is mostly a pro-coagulant. With small amounts of heamotoxic and cytotoxins. Most bites result in local swelling, pain, irritation and bruising of the skin (no necrosis reports are found) redness, nausea, diarrhoea, abdominal pain, vomiting, dizziness, headache and secondary convulsions and shock. Because most bites are not directly life threatening and the venom is considered ‘mild’ there is no specific antivenom made for the species. This does mean that if you get bitten by these snakes and you have a bad reaction. There will be no anti-venom to help and there are several cases of people going into shock as a result of the effect of the bite of this snake.

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 takes a big sense of responsibility and a sufficient base of experience. We cannot be held accountable for any unfortunate results or mistakes made after reading this article.

That being said. There are a lot of serious well knowledgeable people who keep and breed these interesting snakes. And for someone who has an interest in Asian pitvipers. Ovophis sp. Including the O. okinavensis are great snakes to take care of. They do not get very big. Fit well in a naturalistic setup and have some great and unique behavioural trades.