This species knows two subspecies; these are Coelognathus subradiatus subradiatus and Coelognathus subradiatus enganensis.
Coelognathus subradiatus lives in tropical forests in Indonesia (the Lesser Sunda Islands and the subspecies Coelognathus s. enganensisis said to come from Engano Island ). They are found from 0-1200 meters above sea level.
There are many pattern and colour morphs known, from light brown to almost black. The normal length of an adult snake is about 140-170 cm but there are some specimens of more than 2 meters, but these are quite rare exceptions.
There are only a few people in the world who keep this species in captivity, at the time of writing at least. I would like to bring this very attractive and beautiful species to the attention of many more private breeders and herpetoculturists in the world, they really deserve to be a good deal more popular.
This species belongs to the genus Coelognathus , which are racers, although formerly being described as ratsnakes and once they even belonged to the genus Elaphe before the recent revision. They are very quick and defensive in spirit. You should always treat them with a lot of respect due to this; otherwise you will likely notice the consequences, owing to your poor attention.
They are nocturnal to crepuscular and become more active in evening. Although we do have one male we keep in a terrarium measuring 125cm x 60cm x 40cm, and you can see him often in daytime, he is very calm, and not as defensive as our other snakes.
This species will require quite a big terrarium due to their size and activity levels. We usually keep our Coelognathus subradiatus in wooden cages of 70cm x 60cm x 40cm when they are sub-adult; when they become adult we move them to cages of 125cm x 60cm 40cm. They always seem to do perfectly well in such enclosures. You only have to keep them at the right humidity (about 70-80%) and the right temperature about 27-31 degrees Celsius (80.6-87.8F) for them to fare well. As substrate we use in our cages coco-peat, also in every cage there is a hide box with a water bowl. In the cages of females, I place an additional box with moist sphagnum moss. When in the process of sloughing, the females often use these boxes and for the males, we will just give an extra spray, so the humidity level rises to around 80-90% during their shed cycle.
In the wild they will eat; mice, rats, birds, bats and lizards. In captivity, we feed them only mice and rats, because they have a very quick digestion system you should give them food twice a week. If young Subradiated’s don’t feed over the course of a four week period, they may even die due to their ultra fast metabolism. Once they are born, they normally won’t voluntarily accept any food, whether the prey presented to them is dead or alive. After their first slough, you may need to force-feed them once or twice a week with baby mice. Following their first hibernation, they normally start eating by themselves. You can feed them either live or defrosted fuzzy mice and you will notice that they grow at an extremely fast rate. After two months they may feed on half grown mice and after another three months they might be required to be fed on adult mice.
They need a winter cooling of about two months, with a temperature of about 20 degrees Celsius (68F) and a humidity of about 60%. After their winter cooling, you should give them plenty of food once they are returned to normal temperatures. After their first shedding following this winter cooling, you can introduce males to females and copulation can be pretty much assured. When the females become gravid, you should give them as much food as they want, as they will need all the energy they can muster. After two months you can expect eggs. In preparation for that time, you should put a hiding box with moist sphagnum moss in the cages of females for the purpose of laying the eggs. They will almost automatically drop their eggs (5-10) in these boxes, so check these boxes often!
After they lay their eggs, you can again introduce males to females and you will get eggs again, following the same formula as previously mentioned, they may successfully mate four to six times in a year, a very prolific species indeed.
Short breeding account of Coelognathus subradiatus
I put my (3.4) adult C. subradiatus in ‘hibernation’ for one and a half months at an average temperature of 22 degrees Celsius (71.6F) during the day and about 19 degrees Celsius (66F) at night. One and a half months later, I slowly warmed them up to their normal temperature which for me was about 29C (84.2F) during the day and about 24C (75.2F) at night. About two weeks at this normal temperature I started feeding them with thawed medium sized rats. As normal they are eating like crazy! When I put my hands in the cage they directly started to try to eat my thumbs!
So I fed them two medium sized rats a week, as clearly they were hungry, which worked out pretty well. After about three weeks, shortly after the shedding of the females, I introduced males to the females. This proved to be immediately successful as two of the females were witnessed in copulation, with the introduced males. I was very happy! I started to feed them more and bigger rats, in preparation for producing their eggs. They ate very enthusiastically and around one and a half months later, I found six eggs and five eggs laid by both the females respectively in their hides with the moist sphagnum moss. I was very glad as this was my first breeding with subradiatus! Unfortunately, the happiness changed when I found three eggs rotten 65 days later out of the clutch of six. However at the 101st day, I saw the first egg piping! Again, I was very pleased, about 4 hours later I also saw a second egg hatching. The third egg I cut 1 day later open but it contained a dead embryo fully deformed, which was very sad.
Fortunately the other 5 eggs all hatched perfectly at 98 days of incubation at a day temperature of about 29C (84.2F) and a night temperate of about 25 degrees Celsius (77F). After their first shed, I probed the seven neonates and they only contained a single male! I found this to be quite disappointing.
At the time of writing, I have successfully hatched another clutch of 4 which also contained only one male. I have, in addition, another 5 eggs in the incubator and again 2 gravid females. These snakes are breeding like the proverbial rabbit