By Paul Donovan
Although I have worked with reptiles for the past 30+ years and it is always exciting to stumble across a species you have only ever seen pictures of while walking in the bush, one of my most memorable finds was actually a creature almost 20cm in length and had 20 pairs of legs. Yes, you’ve guessed it, it was a Giant Centipede.
I can remember many years ago buying a large Scolopendra, and during the process of transferring it from its tiny incarcerated container into a more suitable housing, I said to my friend “these things move darn quick”, just as I finished the sentence, this Scolopendra shot out of the box and scurried across the floor towards my friend. Well, my friend was a big guy, but that day he moved with the speed and grace of a sprinter!
It’s not an insect or an arachnid
If it’s not an insect or an arachnid, then what is a centipede? Well, centipedes are distant relatives of crustaceans (lobsters, crayfish and shrimps etc.) and belong to a class called Chilopoda. The reason they are neither insect or arachnid, is that they have multi-segmented bodies, (more than the three seen with insects, and two with arachnids) and, depending on the species, can have between 15 and 177 pairs of legs; one for each body segment. This compares to the 6 pairs of legs for an insect, and 8 pairs for an arachnid. So, although it may be easy to refer to a centipede as an insect or arachnid, it is actually neither.
A class of 3000
In the class Chilopoda, there are some 3000 species set within five orders, and fifteen families. Of these, Scolopendra (order Scolopendromorpha) which account for some thirty species, are the most frequently available in the pet trade due to their truly impressive sizes. For an animal which spends most of its time hidden beneath rocks or fallen logs, and is nocturnal by nature, they can be surprisingly colourful, ranging from subdued browns to green, orange, purple, and even dual coloured; though classifying them is exceedingly difficult. Centipedes occur in biotypes ranging from moist, to dry ground, though it is never bone dry. They occur beneath stones, logs and cracks in rocks where humidity and temperature remains pretty constant.
Typically they are long spindly bodied arthropods whose legs on the first body segment are modified into a pair of large claws (maxillipeds) and are associated with a pair of venom glands. The venom varies from species to species but is powerful enough in the larger species to kill small rodents. There are 4 single eyes on either side of the head, though one would assume these to be quite primitive in structure, and play significantly less of a role in prey detection than the very tactile antennae would.
Respiration is via a tracheal system, this is where a small hole on each body segment called a ‘spiracle’ leads to a network of tubes within the body which transports oxygen to the various systems and takes carbon dioxide away. As arthropods go, centipedes can be quite long-lived. Although it is difficult to give life expectancy figures for the smaller species, certainly the large Scolopendra could live for around eight years give or take.
Captive care
Providing that you can give them the correct conditions, centipedes are relatively easy to maintain in captivity. At the outset, before I get on the specifics of husbandry, let’s talk about caging them. A conventional glass aquarium can be used for housing which should be twice the length of the body and as wide as they are long.
Bear in mind, centipedes may spend their time hidden away, but when they are active they will put a mountaineer to shame. So, when considering the height of the aquarium, this should be at least one-and-a-half to two times the length of the centipede. Remember, they will stand vertically in the corner of a cage and can even gain a foothold on the silicon holding the glass together. This then leads us to a lid; this should be tight fitting. Be under no illusion, if there is the slightest gap, no matter how small it is, even the largest centipede will squeeze through it. So, when I say ‘tight fitting’, I mean just that. Also, be aware that if the roof has any form of zinc or mesh for ventilation, if they can reach it, they will hang from it.
So, now you have a secure cage, how do you furnish it? The substrate should be a mixture of sandy soil and peat, or leaf mould to a depth of four or five centimetres. On top of this should be scattered rocks, logs, broken flower pots etc. Lighting should be quite subdued as these are not light-loving arthropods. Although predominantly nocturnal, a number of the larger species can be active during daylight hours. I used to keep my centipedes in quite a dark corner of the room with a low wattage red lamp for lighting.
For temperature, this will depend largely on where the centipede originates, but as a ballpark figure, I would say between 23-30oC (73.4-86oF) during the day, dropping to17oC (62oF) at night would suit most individuals. As for humidity, 50-70% is a good average. The substrate should be lightly sprayed as and when required to maintain acceptable humidity levels. Care must be taken to maintain correct humidity, as this is the biggest killer of centipedes. If it is allowed to drop below 40% the centipede’s soft skin will begin to shrivel and the individual will die. Equally, a soaking wet substrate which gives a higher humidity may result in the growth of mould and mite incursion.
Feeding
Centipedes are highly carnivorous and prey upon anything which moves. So this is a good enough reason not to try keeping several together. When not eating one another, centipedes will take just about any insect as food up to the size of an adult locust. Some of the larger species will also accept dead pinkies, rat pups and adult mice. These should only be fed occasionally as if fed too often the individual will quickly become overweight. When I kept them, I fed a rat pup once a month and a few insects (crickets, grasshoppers and anything else I can find) each week.
Sexing
If your intention is to have a go at breeding these interesting creatures, first you have to sex them. And this is not as easy as it seems. I find it amusing when people sex animals by adopting the ‘adult males are larger than adult females’ approach. How do you know that what you have are adults in the first place? They could be an adult female and sub-adult male or adult male and sub-adult female. Sexing using ‘size’ is a very haphazard approach. Although it is difficult to see sometimes, visually the male has an enlarged segment between the rear legs which functions to produce the web upon which a spermatophore (sperm capsule) is set down.
I have only attempted mating the Scolopendra I’ve found here in Botswana once, and it was a nail biting event. These things are as cannibalistic as they come. I gave my pair the best chance of survival as I could and introduced them together in a 120cm aquarium.
The female was placed in the aquarium which was well decorated with plants, and plenty of cover, for a week before the male was introduced. As mating takes place under the cover of darkness, I cannot describe the complexities of their love life from personal observations, but generally the male approaches the female, spins a web on the ground upon which he deposits a spermatophore. This is then picked up by the female where it is transported back to her genital opening. Mating can take several hours and once complete the pair should be separated.
Do not be surprised if you keep a single centipede and then one day find a load of eggs in the cage. A number of species are parthenogenic – that is they can breed without the aid of a male.
Many-legged moms
Several weeks following mating, the female will wrap her body into a circle in a shallow depression in the ground and, depending on the species, lay up to 50 or so eggs. The female is very maternal towards her eggs, and not only protects them from predators, but lovingly cares for them as any mother would a new-born baby. She protects them from mould and infection by, among other things, licking them.
Throughout the period of incubation the female exudes a disinfectant which is used to cleanse the eggs. The importance of this can be seen if she is removed from the eggs, which will quickly develop mould. As a rough rule of thumb, incubation takes around 60 days with the offspring remaining with the female in the depression for three or four days before moving off to lead an independent life.
Whatever you do, do not disturb the female, otherwise she may eat the eggs and/or young. A number of the larger Scolopendromorpha are what are termed ‘Matriphagic’ – that is the young eat their mother. This is a common behaviour witnessed by some species of spiders, and is probably a way of the mother giving her offspring a ‘kick-start’ in life.
The young are usually creamy-white at birth and should be removed and cared for independently to avoid cannibalism. Interestingly, when the young centipedes shed their skin they eat it, as it contains important nutrients. Sexual maturity takes place within 12 – 14 months.
Painful bites
Be under no illusion about this, a large Scolopendra is capable of delivering a very, very painful bite which should not be underestimated. A bite can give rise to swelling of the bite site, skin discolouration, headache, nausea, and fever. Breathing difficulties and irregular heartbeat are also not unheard of. Fortunately, most side effects are short lived, and subside within two to three days with no lasting effects. If you suffer a bite, clean the wound with soap and apply an antiseptic cream.
Care should also be taken to avoid contact with the legs as they produce a secretion which can result in allergic reactions leading to a nasty itchy rash. An antihistamine cream will alleviate itching. In exceptional cases, people who are allergic to any type of insect venom could be at risk of anaphylactic shock from a centipede bite, so be aware of that. As interesting as centipedes are, they are definitely not suitable for children.
Handling
There may come a time when it is necessary to relocate your centipede from one cage to another for whatever reason. Don’t even contemplate trying to pick it with your hands. Although there are people who are quick enough to grasp it behind the head and at the base of the tail to neutralise it, these are few and far between; if you miss, you are going to get bitten very badly. I wouldn’t attempt to pick up a large Scolopendra for love or money.
To move them, it is better to place a container or a length of piping which has been blocked off at one end, (in which the individual can crawl), in the cage. Once the centipede is inside, secure the other end off. You can also pick them up with a pair of long forceps. These should have foam wrapped around the tips, so that as you grasp the centipede it causes it no damage. Be prepared for the thing to wriggle like nobody’s business, though, and listen carefully, because you can hear them chomping on the metal.
Do not be tempted to lift an individual from the cage, because if you drop it…. bye, bye, centipede! Have a container inside the cage ready to transfer it into. Even this is not easy though, because you then have to let it go while at the same time trying to secure the lid. Nevermind, a few goes may succeed!
Centipede or millipede?
Centipedes have 22-25 pairs of legs – one pair per body segment whereas millipedes (which belong to the class Diplopoda) have two pairs of legs per body segment giving them between 26 and 300 legs.
Tail-end
For all their shortcomings, centipedes make quite interesting ‘pets’ and there is still much we need to learn about their biology. I find them fascinating, if not a bit scary. Just please don’t give them to your young son or daughter as a birthday present!
Brought to you by BlackBox Reptile Cages
