MORE THAN A BOX OF SAND

Busting the many myths of sand boa husbandry.

Sand boas (Eryx sp.) are a fascinating, yet often overlooked group of snakes that have been kept and bred by specialist keepers for decades. As their common name suggests, they live predominantly fossorial lives and have developed unique adaptations to thrive in harsh arid environments. Whilst many hobbyists disregard them as uninteresting and reclusive snakes, perfecting the captive husbandry of these animals can be a complex and rewarding endeavour.

Eryx

There are twelve distinct species of sand boa and several subspecies. They are an extremely widespread genus, stretching across Africa and Asia. Eryx jaculus can even be found in Europe as far West as Greece. There are also several threatened species in India and Sri Lanka. Each species exhibits subtle differences indicating which environments they inhabit. All are short, stocky snakes which help them quickly submerge beneath the sand. They have also developed (to varying extents) a hardened shovel-like nose to allow them to dig through soil and manoeuvre through root systems. Most also have intricate dorsal patterns, to break up the shape of any exposed parts of their body and protect them from aerial predators. Species from sandy environments, such as the Arabian sand boa (Eryx jayakari), have eyes on the top of their heads to allow them to stalk prey within loose sand. Their comical appearance has given the sand boa a reputation far removed from their fierce predatory behaviours. The colouration of all species varies drastically depending on locality and sex. Males tend to be smaller but much more vibrant. Because they are so widespread and live reasonably cryptic lives, taxonomists are still regularly making distinctions. Most famously, almost the entire Eryx genus was recategorized as Gongylophis between 1999 and 2010.

As ambush predators with straightforward care requirements, sand boas can and have been kept successfully since the 00s. Previously, they were imported from various countries including Tanzania and Pakistan which have since ceased exportation of live animals. Now, all species are CITES listed, which means trade is regulated. Whilst the number of sand boa species available today is a fraction of what it was in the 90s and 00s, good numbers of captive-bred individuals are still being produced. Unfortunately, their simplistic environmental conditions and a misleading common name has created a mirage of myths around the care and keeping of sand boas across the world.

Sand boas in captivity

Chris Jones has kept sand boas for 20+ years and has maintained a collection of over 100 snakes across eight distinct species during that time. He has produced several articles and essays on the husbandry of the Eryx genus throughout that time and supported multiple publications on the topic. “Sand boa husbandry really hasn’t advanced much in recent years and that’s something I want to change” explained Chris. “The reality is sand boas are not and are never going to be the most popular pet species because frankly, they hide a lot. That doesn’t mean we can’t provide better husbandry methods.”

There are several species which are readily available in the UK. Although the

Kenyan sand boa is the most popular, the Saharan sand boa (Eryx muelleri), rough-scaled sand boa (Eryx conicus) and Russian sand boas (Eryx miliaris) are also frequently available. “Saharan sand boas are second most popular in the UK because they have been imported as wild-caught for quite some years” added Chris. “Years ago, this used to be why the Kenyan sand boa was so popular, but you can’t do that anymore. Various countries have stopped imports and Tanzania has now been closed for some years. There are now people breeding Saharan sand boas in captivity, which is nice to see. They’re also a very interesting species to breed as they’re an egg-laying species which is extremely unusual for Boids. Eryx muelleri and Eryx jayaraki are both egg-layers and provide a unique breeding opportunity for hobbyists who were working with them many years ago. The embryos develop inside the eggs within the female’s body for most of their development time. When the snakes are near the end of their development cycle, the female will lay her eggs. So, once they’re laid, they’re supposed to hatch after just two weeks.” As species which inhabit the harshest of environments, this natural adaptation has allowed the gravid females to protect their offspring from dry, hostile conditions and ensure the eggs receive enough hydration to successfully develop.

The popularity of captive-breeding sand boas has naturally progressed into ‘line breeding’ to create morphs.

These were initially produced in America starting with albinos and anerys. Today, there are dozens of line-bred morphs in the USA. Chris continued: “I was the first to bring in the Indian sunset sand boa (Eryx johnii). Although the species had been kept in the country before, Rick Staub in the USA line-bred them to produce the ‘sunset’ variety. Traditionally, as a baby, that species starts off orange and eventually grows into a more drab, brown colour. His selective breeding has now meant that there are highorange Indian sand boas in the hobby.

As well as genetic mutations, various localities such as the “Dodoma” from Tanzania, have brought new colourations and patterns into captive-bred animals. Slowly, these morphs reached Europe and are now becoming increasingly popular in the UK. Chris continued: “Eryx rufescens was once thought to be a separate species. I and many other enthusiasts disagreed with this, and it is nice to see it is now considered a locality variation of E. colubrinus. Because of this recategorization, nowadays we are starting to see “striped” and “granite” sand boas, which have been produced by breeding two naturally occurring locality variants.”

Some populations are extremely rare and protected by international law. The rough-scaled sand boa (E. conicus) comes from India, Sri Lanka and Pakistan. As a region with an alarming rate of snakebite fatalities, instances of human/animal conflict are extremely common. Researchers who are often called out to remove ‘problem’ animals, many of which are nonvenomous snakes, have identified and photographed a naturally occurring population of albino rough-scaled boas in Western Maharashtra. As India is closed for export, this population is protected and provides remarkable insight into an ecosystem that allows snakes with albinism (usually an extremely detrimental mutation) to survive well into adulthood.

Sand boa husbandry

Chris has been looking toward natural husbandry methods for a long time, which allowed him to become one of the first UK hobbyists to successfully breed Russian sand boas. This is because he adopted a slightly different approach from many of the commercial breeders at the time. “I didn’t put them into a tub with a heat mat on a thermostat and hope for the best, which is what a lot of people were doing back then” explained Chris. “Sand boas, particularly the Russian species, can be exposed to very harsh winters and very hot summers. Back then, instead of a heat mat underneath, I had a halogen heat lamp to provide overhead heat. The hot spot was more than 42°C. But, all year, I would turn this off at night, so they had no additional heat. During the summer it was warmer and during the winter it was obviously colder, so I basically just changed the photoperiod.

“In the run-up to the breeding season, I would wait until it was raining outside, so the air pressure drops, then I just flooded the tank. I would pour a jug of water into the substrate and completely drench the enclosure. Gradually, as it was warming up, I let the enclosure dry out naturally over a few weeks. Once the enclosure had fully dried out again, I introduced the animals together and they bred successfully. I also applied this technique to Eryx tartaricus (now E. miliaris) from different localities. These were separate subspecies E. t. tartaricus and E. t. speciosa and again, I managed to breed these under the same conditions as the Russian sand boas.”

Mimicking wild conditions, even if they do appear extreme, can provide a wealth of benefits to captive species. From prompting breeding behaviour, to improving health and vitality, the seemingly harsh seasons that reptiles and amphibians face in the wild are important to their biological functions. Whilst keepers must protect their animals from potentially life-threatening conditions, understanding and recreating the native ecosystems of a species should be a goal for all keepers. With new research and products available, hobbyists have de-bunked many of the myths surrounding sand boa husbandry.

Myth 1

Sand boas only feed on rodents.

In the wild, Kenyan sand boas (and possibly other species, though it has been less widely documented) will eat birds as well as rodents and reptiles. Even though they are primarily fossorial, Kenyan sand boas will opportunistically feed on most suitably sized prey that crosses their path. They often inhabit grassy areas and woodland edges and therefore encounter a variety of prey items including fledgling birds that have just left the nest. In captivity, chicks are readily accepted. Their high fat content is likely to be a welcome treat and one which would, in the wild, support a period of brumation or reduced feeding activity. “There are also other ways of providing an enriched diet” added Chris.“For example, don’t just feed the same sized mouse every time. Maybe one day stick a few pinkies in there. Next time, go for an adult mouse. Although chicks may be a little too large for a male, they can add some variety to an adult female’s diet.”

Another major misconception about sand boas is their fossorial behaviour. Whilst these ambush predators will indeed spend most of their time beneath the ground, as the sun sets, they will emerge to explore. They have even been recorded in elevated positions in tree trunks and amongst tree roots. In captivity, even the largest enclosures will not provide the same climbing opportunities as a wild sand boa might utilise and therefore, all climbing opportunities are likely to be utilised. Active males will leave the substrate to explore branches and cork bark tubes and so it is a good idea for keepers to maximise the potential of their enclosures by providing branches and décor above the substrate.

Myth 2

Sand boas live in the sand.

It is completely understandable why people might think this. Not only is there a clue in the name, but the most famous sand boa species to those who are not herpetology enthusiasts is the Arabian sand boa. This species is extremely well adapted to harsh deserts with eyes on the top of its head and a pointed snout. Its comical appearance might make it the star of many nature documentaries but it is rarely kept in captivity and thus does not represent the requirements of most commonlykept species. In fact, most sand boas inhabit semi-arid locations and some experience seasonal monsoons. Therefore, a bone-dry tub of play sand does not provide an enriched or naturalistic environment for any of the readily available species.

Chris continued: “Should you keep sand boas on sand? Broadly speaking, no. I have tried many different substrates over the years, and I don’t like sand on its own. It’s just not that natural. Instead, a natural substrate would be more akin to the ProRep BioLife Desert substrate. Or, if you ignore the name, LeoLife is brilliant for rough-scaled sand boas that come from the same India/Pakistan region as leopard geckos. The important thing here is that it’s a loam/clay mix. In some cases, they will want to create a small burrow area which is possible with a clay mix, as opposed to sand which will just collapse in on them all the time. They also hold moisture and they’re just prettier. I’ve also tried using ProRep Tortoise Life which is great for Russian sand boas as well as TortoiseLife Bio which will hold a lot more moisture. I’m testing that one at the moment, but it’s going well. The point is these animals do not come from the Saharan desert where you picture dunes as far as the eye can see.”

Myth 3

Sand boas never see the sun.

Sand boas are mostly nocturnal and spend most of their time beneath the surface of the ground. However, almost all species have been photographed above the surface, during the day (or early evening) at some point. Therefore, full-spectrum lighting is a necessity for Eryx, even if they don’t openly bask like Uromastyx or Testudo from the same regions.

“I’m a firm believer that overhead heat is the right approach” added Chris. “Burrowing animals that reside in deep layers of substrate - particularly underneath a hot rock - will naturally receive heat for several hours after dark. Not only is a spot bulb more natural, but you’re also providing visible light. Sand boas are not strictly nocturnal. I’ve seen them regularly out during the day, depending on the species. There’s a good cause to offer natural light and UV but unfortunately, not enough studies have been done on those species. I must say, I have never seen any sign of ill health in sand boas for not receiving UV. But, as we research more species, we’re learning more about the benefits of UV, so I believe it should be made available to them regardless. In this case, a Zone 1 T5, alongside a flood spot would be perfect.”

The photoperiod is also very important and allows the keeper to simulate seasonality. Although water can be introduced to the enclosure to mimic monsoons, daylight hours are one of just a few of ways that a keeper can provide seasonal fluctuations for their sand boa. “Don’t just leave the lights on for a flat 8 hours a day” added Chris. “In the summer I’ll have mine on for 12-14 hours a day, in the winter it might go down to about 7 hours a day. When there’s more light, there’s also going to be more heat. By leaving the spot on, it’ll naturally provide more heat, but I would still turn everything off at night assuming the keeper has normal household living conditions. The snakes need these sharp night-time temperature drops and maintaining a good photoperiod schedule will ensure the snake can thermoregulate effectively.”

Myth 4

Sand boas are easy to house.

Broadly speaking, sand boas have very manageable care requirements. However, it is important to select the right enclosure for the job. Chris explains: “Sand boas are incredibly strong for a snake. When they want to get their head into something, they are one of the strongest snakes pound-for-pound. Depending on the species, they also have hardened shovel-like noses, so if they want to get into any nooks and crannies in a wooden vivarium, they potentially could get out. I would certainly lean towards a glass enclosure to house these animals. Although, a very young sand boa could potentially escape from some of the ventilation holes in an ExoTerra or ZooMed terrarium. While the snake is still small, the keeper should consider blocking these holes.” A glass enclosure will also provide more depth for the substrate and allow the keeper to easily mount overhead lighting that is completely out of reach of the snake.

Many keepers are exploring bioactive enclosures nowadays. Even novice keepers can create incredibly naturalistic enclosures for a whole plethora of species. Sand boas are no exception, but special considerations need to be made for their exploratory behaviours and strength. Firstly, the enclosure must be large enough for the snake to manoeuvre around its environment without constantly damaging the plants’ roots. This damage can be mitigated by choosing strong agave plants, which can be planted into the substrate whilst still in their pots. If they are dislodged, they can simply be re-planted. Whilst juvenile sand boas are much less destructive, it is a good idea to allow an enclosure some time (6 - 12 months) for plants to become well-established before introducing an adult sand boa. Once the plants are well rooted, even the bulkiest of sand boas will struggle to uproot them completely. The keeper should identify areas where the snake is most likely to burrow (generally under hides, or beneath the basking spot) and avoid over-planting in these locations.

Sand boas in herpetoculture

Sand boas can make excellent pets when cared for properly. However, they may not be appropriate for all new keepers. “In terms of ease-of-keeping, I would say that sand boas are a great beginner snake” Chris added. “Are they the best beginner snake? No. In my opinion, a corn snake will always be the best because most people want something more visible and better to handle. However, if a new keeper is looking to keep a sand boa, I would recommend males because they’re smaller, skinnier and a bit more active too. They are also generally more available and perhaps cost a little less, as most breeders are searching for females. Males are also less likely to destroy plants, so a new keeper can get more creative with their enclosure design. Having said that, they’re not always radically different. For example, a Kenyan sand boa male will be quite a lot smaller than the female – perhaps 2/3 of the size. Indian sand boas, on the other hand, show very little difference.”

Ultimately, it is the responsibility of the keeper to do as much research into the species as possible, long before acquiring an animal. Having a multi-faceted approach, by speaking to keepers, breeders and herpetologists as well as researching the wild conditions of this species will ensure that the animal receives the best care and the keeper feels fulfilled in their husbandry practices. Whilst many hobbyists are quick to assume Eryx husbandry is just “keeping a box of sand”, those that are truly passionate about the species can find sand boas to be some of the most fascinating pet snakes available.

Biosecurity is a term used to describe the measures used to prevent the spread of harmful biological substances. In 2020, the world became acutely aware of ‘biosecurity’ in its fight against the spread of COVID-19. At times we were instructed to wash our hands, at other times PPE became mandatory in enclosed spaces and, across the world, every country had a slightly different approach to keeping their population safe. The public looked toward their government officials to protect them from rising cases, new variants, and localised outbreaks. Whilst we may be teetering on anthropomorphism, keepers have both an ethical duty and, in some cases, an economic interest in practising good biosecurity to protect their animals.

Birds and avian flu

With Avian Flu still considered a major threat to birds in the UK, biosecurity is a top priority. Dan Sutherland, Animal Management Team Leader at Hadlow College says “we manage a range of rare duck species here at the college. Since the recent outbreak of avian flu, we’ve had to be extremely careful about who gets to work with these animals. We have foot dips for every enclosure, but whenever anyone needs to do maintenance on the waterfowl, they must wear full PPE. We’re also very careful about which other animals they work with on that day.” As an educational facility, exposure to biosecurity methods can provide valuable insight into professional environments. ‘Foot dips’ are a universal tool used by most zoos and farms and are comprised of a shallow, absorbent mat filled with a powerful disinfectant to prevent the spread of pathogens that might be found on the ground or in soil. Therefore, many territory borders (including countries like Costa Rica and Australia) ban visitors from entering with muddy boots.

Breeding facilities are even more stringent in their approach. Psittacus is a breeding facility for many psittacine birds, with a focus on African grey parrots (Psittacus erithacus). As well as manufacturing Psittacus Foods, their facility produces many captive-bred parrots for European hobbyists. Their biosecurity methods are arguably more stringent than most collections in both the zoo and private sector, to ensure the health of their breeding pairs and offspring. Helena Marqués, Training and Technical Manager told Exotics Keeper Magazine: “Our breeding pairs were quarantined and tested for Circovirus, Chlamydiosis and Polyomavirus at the beginning of the project. We haven’t introduced any more external breeding birds. When we’ve needed to replace some of the breeding animals, we have used individuals bred in our breeding centre. We annually check all of our chicks to guarantee our customers that they are purchasing a healthy animal. Additionally, it is a way to retest our centre.”

“We also have strict protocols for staff regarding hygiene, clothing, and staff movement. External visitors are not allowed in any of the facilities holding animals and when they are (repair works for example), they are required to follow strict measures of hygiene and wear special clothing. External objects like cell phones are not allowed either, since they are a potential vector for diseases. We have a pest control plan and all our facilities are indoors and there is no possibility of contact between the native fauna and our birds. This allows us to guarantee the safety of our birds whilst protecting wildlife from pathogens that do not affect the African greys, but that could be potentially harmful to them.”

Amphibians and wastewater disposal Amphibians are perhaps the most delicate of all commonly kept exotic animals. Unfortunately, they are also some of the most susceptible to mortality from disease transmission. Globalised diseases such as Chytridiomycosis have been linked to huge declines in wild amphibian numbers since its discovery in 1938. Although some success stories have surfaced, the picture remains very bleak. A review from the academic journal Science in 2019 stated that the disease chytridiomycosis was a factor in the decline of at least 500 species of amphibians in the last 50 years, and declines >90% in more than 100 species. Alarmingly, the study also presumed ‘extinction in the wild’ of 90 amphibian species because of the disease.

Chytridiomycosis is caused by amphibian chytrid fungi. Scientists have known about one of these chytrid fungi, Batrachochytrium dendrobatidis (often abbreviated to Bd) for decades. In 2013, another chytrid was identified as causing population declines in European salamanders. This chytrid, Batrachochytrium salamandrivorans (Bsal for short) has already reached the UK in captive collections and as a result, it is illegal to import Caudata (salamanders and newts) without a screening and quarantine process. Bsal is thought to have originated in Asia and is likely to have spread via the trade of laboratory animals, or via stowaway amphibians from other regions hitching a ride in cargo and finding its way into the environment. There is also concern around wastewater being introduced into the environment from captive, non-native amphibians. This is another reason why biosecurity is extremely important. Not just to protect a captive population from external pathogens, but to protect native wildlife from introduced disease.

Chytrid fungi can infect a wide variety of host species; some asymptomatically. These species may act as reservoirs of infection that facilitate the spread of the pathogen in their environment. The zoospores of the fungus are motile in water and require cool, moist conditions to survive. Here in the UK, conditions are perfect to allow the disease to spread and can even spread within collections. Amphibian skin works in complex ways to allow respiration, thermo- and osmoregulation. Chytridiomycosis disrupts the water and mineral balance of diseased amphibians which results in death, normally because of electrolyte imbalances that lead to heart failure.

Chytrid is not the only disease that amphibian keepers should be concerned about. Ranavirus, ‘red-leg’ disease and newly emerging forms of ‘Perkinsea’ are all illnesses that can have disastrous effects on amphibians, but which often lie undetected in water. A responsible keeper should: Never dispose of wastewater from an amphibian enclosure near running water. Where possible, try to disinfect any wastewater before disposing of it. Avoid using old bioactive enclosures for new animals, even if the previous inhabitant had no symptoms of ill health. Try to avoid keeping amphibians outside and if amphibians are kept outside, ensure that they are secure and safe from cats or birds which might remove them from their enclosure. Report any mysterious deaths of amphibians to your exotics vet or, in the case of native amphibians, to Garden Wildlife Health.

Treating all water/liquid that has come into contact with your frogs as a biological hazard is the first step to ensuring high standards of biosecurity.

Reptiles and cleanliness

Reptiles can also fall victim to disease without the preventative measures of a biosecurity protocol. The best way to protect our reptiles from disease is to ensure that pathogens cannot be easily spread between individuals, or from the keeper or the environment. There are several illnesses which can affect commonly kept reptiles, with protozoal illnesses such as coccidia and cryptosporidium proving to be quite prolific. Respiratory problems can be caused by fungal infections or materialise as a symptom of other viruses. We are learning more and more about Adenovirus and its natural position in wild animals, but in some species, this can also cause death. Broadly speaking, the best way to protect reptiles from transmittable diseases is to ensure that there is no possible way for the disease to transmit from one animal to another. Reptiles, although they can typically hide it well, will eventually show signs of ill-health much sooner than amphibians.

When it comes to disinfecting surfaces, it is important to consider all methods of transmission. In some cases, an institution that keeps several hundred animals can still have a more successful biosecurity protocol than a pet keeper, that maintains several pets but handles them regularly. Keepers must also consider their clothing as a means of transmission. Therefore, safe disinfectants such as F10 are useful, as they allow the keeper to spray their clothing and footwear without causing damage or potential health problems. F10 is often chosen by zoological institutions as it is universal in its application. It has three core actives that kill bacteria, viruses and fungal spores, but can be used in misting systems to kill harmful bacteria in the water, as a nebulising treatment for respiratory problems and as an ointment for wounds. It can also be used to disinfect surfaces, equipment, and enclosures, with the animals in-situ. Providing the keeper has the correct dilutions, this universal formula is great for a whole host of uses. More recently, many collections are running F10 through a fogging system to help clear water droplets in bioactive enclosures, as well as disinfecting the filters of air-conditioning units to prevent the spread of airborne pathogens.

Anyone who has more than one animal should implement some form of quarantine process when introducing a new animal into their collection. A good way of doing this is to set their enclosure up in another room and maintain the animal there, for a period of one to three months. Disinfect everything when moving between the two rooms, then clean the whole set-up before reinstalling it into an ‘animal room’.

Biosecurity in aquaculture

Fish and aquatic animals require just as stringent biosecurity regimes as terrestrial animals. In fact, higher population densities of fragile fish, often sourced from the wild means that fish are amongst the leastforgiving of all animals when it comes to biosecurity. Keepers must be extra vigilant in this regard and enact due diligence from the moment they get their animals.

As with all taxa, it is important that the keeper researches the species in depth before acquiring them. Some fish are much more susceptible to disease than others and in fact, some lineages of fish are even more susceptible or tolerant of pathogens. Having a reputable breeder with a strong understanding of the history of the fish can prevent certain pathogens from being introduced to a collection and make it easier to identify and treat illnesses that have taken hold.

Quarantine procedures are also important for fish, but to the average aquarist with a single, large fish tank, this is not always easy to achieve. In this instance, observe the animal closely to pick up signs of ill health as early as possible. Act quickly to remove any fish that is presenting signs of illness.

A lot of common pathogens that affect fish such as Aeromonas and vibrio bacteria are exacerbated by poor husbandry or bad water conditions. Some pathogens can live undetected in the water and even infect fish without causing any symptoms, but a change in temperature can prompt the pathogen to multiply and quickly kill an entire tank of fish. Regular water testing, particularly when a new fish has been introduced into a tank is key to combatting this issue. Other pathogens are less forgiving. Herpesviruses can be carried by asymptomatic fish but have a disastrous impact on susceptible species such as koi.

Some issues associated with harmful pathogens and disease are only realised once the fish is stressed. An unclean, overcrowded or highly territorial environment will cause one fish to fall ill, but quickly affect other fishes. Biosecurity therefore spans all husbandry practices, and any unexpected mortalities should be treated as a biohazard, with all water disposed of and equipment thoroughly disinfected before they are used again.

Is it that simple?

Biosecurity is often reduced to ‘keeping clean’, but it is much more than that. A good biosecurity protocol can prevent life-threatening pathogens from spreading between animals, collections and the wider ecosystem. Even an animal which has been kept solitarily for many years could still harbour diseases asymptomatically. Of course, a large-scale breeding facility or a rescue centre that rotates animals daily, will require a slightly different protocol to the average pet keeper. However, anyone who keeps animals (even more so for exotics keepers) should ensure they have a good quality disinfectant, rubber gloves and some level of PPE available in case of emergencies. Even something as straightforward as ‘quarantine’ can vary between species and there are numerous types of ‘quarantine’ designed to isolate certain pathogens easier than others.