Appeared in ‚Reptilia‘ Issue 34
Some people may wonder: of the thousands of snake species that exist in the world, why choose sand boas? Well, I sometimes wonder myself, but I do have a few good reasons. There are several species, subspecies, and varieties of sand boas, each with its own characteristics and „personality.“ They are small, easy to care for, and relatively simple to breed. In fact, it is really too easy to build up a large collection.
Of the numerous species and subspecies that I keep, the European and central Asian sand boas are my special focus. These species occur across huge ranges, making considerable variety even within subspecies inevitable. Every individual sand boa is unique, and can be easily distinguished from others. The variety of patterns fascinates me, and whenever I see a remarkably different-looking sand boa, I attempt to purchase it.
This species is one of my personal favourites. There are three subspecies that occur in southern Europe and into northern Africa. Unfortunately it has not become a popular pet snake, primarily because of trade restrictions — this species is listed in CITES Appendix II and Annex A of European legislation. Within the European Union, every Eryx jaculus specimen must have identification papers. This is too much hassle for many breeders, who therefore choose not to keep this species.
Eryx jaculus jaculus, the javelin sand boa, is the most commonly available subspecies. Many captives are of Egyptian and Jordanian bloodlines. This subspecies grows slightly larger and is more heavily built than the other two subspecies. It is also slightly more aggressive, but captive-bred specimens can be tamed and become easy to handle.
Eryx jaculus turcicus, the Turkish sand boa, is predominantly found in Turkey and into Syria. It is smaller than Eryx jaculus jaculus and rarely available in the pet trade. There are a few breeders working with this subspecies, so I hope it will become more common.
Eryx jaculus familiaris, the Bulgarian sand boa, is more slender than the other Eryx jaculus subspecies. It is also the most docile, and has an intricate pattern, making it perhaps the most pet-worthy of the three. Nonetheless, it is very rare in captivity and becoming increasingly scarce in the wild. I am currently working with a group of six specimens, which I hope to reproduce in 2005.
This species is divided into two subspecies: the more commonly seen Eryx miliaris miliaris, the brown Russian sand boa; and Eryx miliaris nogaiorum, the black Russian sand boa. With selective breeding, I hope to produce several variations of these subspecies. My primary project is to produce a captive-bred line of the „super black“ Russian sand boa, a naturally occurring form of Eryx miliaris nogaiorum that is almost completely jet black, with only a few white and grey speckles running down the sides.
Every few years, Russian sand boas of both subspecies are brought into Europe in relatively small numbers. Wild-caught adults do not make the best of pets, and many are rather bland in colour, making them unattractive. This is not likely to become a generally popular pet species, but it will always have its place in the hearts of many enthusiasts. I hope that captive-bred babies will be more desirable, encouraging hobbyists to keep this species.
This species is divided into three subspecies: Eryx tataricus tataricus, which I call the Tartar sand boa; Eryx tataricus speciosus, which I call the spotted sand boa; and Eryx tataricus vittatus, which I do not currently have in my collection.
This is the second largest species of sand boa, with females often reaching lengths of 36 inches (91 cm). I have found this species remarkably easy to maintain. The snakes are generally quite docile and easy to feed. All of mine readily take thawed rodents.
This species is rarely seen in captivity, but because of its attractiveness and good disposition, I am confident that it will become more popular and readily available in the future. Eryx tataricus speciosus is especially attractive, and sought after by many enthusiasts. I have a long waiting list of people who want this subspecies, even at the relatively high prices dictated by short supply and high demand.
It is now illegal to capture wild Eryx jaculus (my group consists of captive-bred individuals from various European breeders), so this section on acclimation to captive conditions refers mainly to Eryx miliaris and Eryx tataricus. There are a number of procedures I follow when dealing with wild-caught snakes. Following is a step-by-step guide to acclimation.
1. The first and foremost thing to deal with is external parasites. Actually, sand boas rarely carry any form of mites or ticks, but a bath and parasite removal should be done as a precaution. There are several products on the market for removing parasites. I prefer one that is often also used for fleas on cats and dogs.
2. My next step is to try to get some food into the snake. The first couple of meals should be approximately two-thirds the girth of the snake — if your snake is 3 centimetres in diameter, a rodent with a diameter of 2 centimetres is appropriate. It is important that the first meals stay down with no regurgitation. Once your snake is feeding regularly, you can increase the size of prey to slightly larger than the girth of the boa.
3. When the snake’s feeding response is established, treatment for internal parasites should be carried out. I use fenbendazole at 50-100 milligrams per kilo of snake body mass.
4. After treating for parasites, it is important to make sure the snake’s feeding pattern is reestablished. In most cases, the snake will continue to feed without a problem, but sometimes a specimen will need some help. I use a water-soluble probiotic containing enzymes, vitamins, and minerals, which helps to stimulate a feeding response. This is added to the snake’s water every day for about 10 days.
5. Finally, establish a weekly feeding routine. Make sure the snake stays healthy, and develops optimal condition in preparation for breeding.
Brummation is torpor or inactivity associated with prolonged periods of low temperature, during which metabolism is reduced, but without true hibernation. This is a most crucial factor in getting these species to breed, and it is important to cool the snakes in a well-thought-out and proper manner.
Before temperatures are reduced, the snakes must be prepared for withstanding several months of low temperatures with no food. Starting in September, females should be fed every 5-7 days with two rodents of approximately the same girth as the snake. Males do not need as much energy reserve, and can be fed a single prey item every 7-10 days. At the end of October, feeding should be stopped altogether. During the following 2 weeks, the snake should be digesting its last meal and excreting most of the waste, before temperatures drop below the normal 86-88ºF (30-31ºC).
From mid November to the beginning of December, temperatures should be gradually reduced to 46-50ºF (8-10ºC). It is not critical that the temperature decrease by the same amount every day. Begin by simply turning the heat source down and then off. After that, moving the snake onto the floor or into a cooler room may reduce the temperature another few degrees. By the end of November, a permanent place must be prepared where the temperature will stay constant at 46-50ºF (8-10ºC). Eryx jaculus will breed after being cooled down to only 52-56ºF (11-13ºC), but Eryx miliaris and Eryx tataricus need the lower temperatures.
I live in southeastern England, where winter temperatures are normally consistently lower than needed for brummation. For me it is easiest to put the snakes in a place with outside temperatures, and use a low heat source to maintain the right temperature. I use a large, display freezer with heat mats controlled by a pulse-proportional thermostat. The sensor is placed in the middle. Since heat rises, the top half of the unit stays warmer than the bottom half, which is useful for wintering several species with different temperature requirements. I place my Eryx jaculus in the top half, and Eryx miliaris and Eryx tataricus in the bottom half. If you live in a warmer climate, a controlled refrigeration system may be necessary. Wine chillers are relatively inexpensive, and work well, but it is important to get one with a built-in thermostat so temperature can be accurately controlled.
At the low temperatures the snakes will be inactive, and should be kept in this state for 3 months. During the first 2 weeks of March, temperatures can be gradually increased back to normal, bringing the snakes out of brummation. Feeding should resume as soon as this 2-week period is over. I feed my females every 4-5 days for the next month. The first two meals should be small — only about half the size of the snake’s girth — to reduce the chances of regurgitation or vomiting, and to facilitate the build-up of digestive enzymes, which are depleted during brummation.
Males and females are kept separate and housed individually except for mating. When placed together, as with many other species of boas, the ratio of males to females may be a determining factor in whether breeding is successful. I have three males, and put all of them in with one or sometimes two females. If I had more males, I would put as many as four per female (never more than two females) together in an enclosure.
Males are placed in the females‘ enclosures starting at the end of March, a minimum of 2-3 days after the snakes have fed. If a snake is refusing food, it is a good idea to try to mate it anyway, as this often triggers a strong feeding response. In fact, males often refuse food after brummation, and do not start feeding again until after mating.
The males should be left with the females for 2-3 days, and then removed so the females can be fed and allowed to digest for 2-3 days. Females need to be fed at least once a week (more often is better) to build up energy reserves before they begin fasting during gestation. The males, on the other hand, can be moved directly from one enclosure of females to another, again for 2-3 days. After a second mating session, however, males should be returned to their own individual enclosures, fed, and allowed to digest for 2-3 days before being put with females again.
I usually observe copulation between 8 p.m. and 2-3 a.m. During this time it is important that the snakes be disturbed as little as possible. They are easily startled, and may move away from each other. Even if copulation is not seen, you will often see the male attempting to „woo“ the female — following her around the cage with his tongue flicking faster than usual, sensing the pheromones that she secretes. If such behaviour is observed, it is likely that this particular pair will eventually copulate.
These snakes copulate most readily just after shedding. A female that is about to shed may not respond to a male that has just shed and is especially rampant. Mating seems to be most successful when males and females shed at the same time. Males usually stop copulating after only about 3 weeks, so it is important — and a little complicated if you have many snakes — to coordinate mating and feeding sessions to take full advantage of the short breeding season.
Ovulation and gestation
Ovulation is the release of unfertilized ova from the ovaries into the oviducts. There they will be fertilized by sperm stored from previous copulation. Before ovulation, a female shows a large swelling at the middle of the body, appearing as though she had swallowed a meal twice the normal size. This swelling is usually present for about 18-48 hours, and disappears as the ova move along and space out inside the uterus (lower part of the oviduct). Female Eurasian sand boas usually ovulate 1-3 weeks after mating. If ovulation occurs, it is quite possible that the female is then gravid (containing fertilized eggs); if ovulation does not occur within 3 weeks, one or two males should be placed with her again.
Fertilized eggs develop inside the female for a period of 3-5 months (usually 4 months). During this period, the gravid female must be able to reach an optimum body temperature of more than 95ºF (35ºC). She should be able to bask at temperatures of 98-110ºF (37-43ºC), but must also be able to escape these temperatures when necessary. The enclosure should be large enough to support a thermal gradient, with a cooler end at 78-82ºF (25-28ºC).
These boas are ovoviviparous. No shells are formed around the eggs, and embryos develop fully while still inside the mother. Babies are born in egg sacs, usually in late June or early July. In the last few days before birth, the swelling of the mother moves toward the tail. Eryx jaculus and Eryx miliaris tend to have 6-12 babies. Eryx tataricus have been recorded to have more than 30 babies, although this is uncommon — usually they have 8-20 babies.
The babies, in their egg sacs, are deposited directly onto the floor of the enclosure. It is best to use a newspaper substrate at this time. The egg sac should not be cut or removed from the babies. They should be left alone and allowed to break free in their own time. They often sit in the egg sac for several hours, absorbing the remaining yolk. As soon as the babies begin crawling around the enclosure, they should be taken out and housed individually. The care of newborns is identical to that of the adults, although they should be kept on damp substrate until they shed their skins for the first time.
Identifying the sexes of these sand boa species is generally easy by simple observation alone. Following are lists of characteristics for distinguishing the sexes in each of the species of Eurasian sand boas.
Eryx jaculus jaculus
Cloacal probe depth (no. of scales) 9-12 2-4
Subcaudal scale count (average) 28 24
Tail percentage of total length 9.5% 6.8%
Adult total length 12-18 in. 20-30 in.
(23-30 cm (51-76 cm)
Eryx jaculus familiaris
Cloacal probe depth (no. of scales) 4+ 2-3
Subcaudal scale count (average) 23 21
Tail percentage of total length 9.5% 8.3%
Adult total length 18 in. 18-24 in.
(46 cm) (46-61 cm)
* Information for males taken from a single specimen
Eryx miliaris miliaris and Eryx miliaris nogaiorum
Cloacal probe depth (no. of scales) 8-12 2-4
Subcaudal scale count (average) 26 21
Tail percentage of total length 11% 7.9%
Adult total length 12-15 in. 20-28 in.
(30-38 cm) (51-71 cm)
Eryx tataricus tataricus
Cloacal probe depth (no. of scales) 11-13 3-6
Subcaudal scale count (average) 31 24
Tail percentage of total length 12.6% 8.5%
Adult total length 24 in. 36 in.
(61 cm) (91 cm)
Eryx tataricus speciosus
Cloacal probe depth (no. of scales) 11-13 3-6
Subcaudal scale count (average) 30 22
Tail percentage of total length 12.6% 8.5%
Adult total length 24 in. 36 in.
(61 cm) (91 cm)