Of all of the hognose species, the Neotropical Hognoses (Lystrophis nattereri and Lystrophis histricus) are the least well known of the Lystrophis clan. Inasmuch as export of these rare and protected species is prohibited, their presence in captivity outside of their native lands is almost unknown .

Because these species are similar in habitat requirements to the tricolors, much of the care information provided is extrapolated from L. pulcher care. Generally, the humidity requirement for these two species will be greater than for Lystrophis dorbignyi and its subspecies.

BASIC REQUIREMENTS

Neotropical hognose snakes are found in temperate zones that range from a low in Winter (June to September) of 13 to 18°C (55 to 64°F), while summer (December to March) temperatures are between 21 to 28°C (70 to 82°F). Rainfall, evenly distributed throughout the year, averages about 1m (3ft) over the entire range of the various Lystrophis. In Brazil and northwestern Argentina where these species of Lystrophis are found, temperatures are more on the subtropical side.

Unlike Heterodon’s reputation for adaptability, members of the Neotropical Lystrophis clan are more difficult to maintain, especially if specimens are wild caught. They are NOT for the novice keeper !

CAGING

Virtually any enclosure, which is suitable for other small colubrids, is suitable for Neotropical Lystrophis. Enclosures such as those made by Neodesha, Vision or Cravenhouse, are generally suitable. I don't care for Vision cages because the sliding glass doors make escape far too easy. Inasmuch as these Lystrophis are small, smaller enclosures such as aquariums, small animal terrariums and plastic sweater boxes are suitable. The main problem with glass aquaria is the tendency for the heat gradient to cause cooler air to settle at the bottom of the cage while the warmer air escapes through the wire top. Glass tops may help reduce heat loss and will help create higher humidity levels which are important for neonate Lystrophis.

One of the keys to a successful enclosure for Lystrophis hognosed snakes is the kind and depth of substrate. South American hognosed snakes are natural burrowers and will be much more successful in captivity if provided with the proper type of substrate that will allow for burrowing. Suitable substrates include bed a beast, a sand,soil and vermiculite mixture, or, probably the best - shredded coconut bedding. Substrates to be avoided include cedar and redwood shavings, bark or mulch, potting soil, and pet litter of any type; these substrates can cause the nares of the snake to become clogged or cause upper respiratory infections. I also don't care for alfalfa pellets - when moist, they easily begin to mold and spread spores into the respiratory systems of snakes. In the case of CareFresh, this substrate can dehydrate snakes so it should be avoided for subtropical snakes that rely on higher humidity levels. Adults can tolerate drier conditions and may be changed over to another substrate at approximately one to two years of age.

It is important to keep these substrates clean and dry to prevent bacterial outbreaks and mold and fungus growth to a minimum. This can be accomplished by providing a water dish within the enclosure, large enough for the snake to soak occasionally. Some snakes will not recognize standing water and must be either provided with a drip system or receive daily mistings.

A hide box is recommended although it may not be used if the substrate is suitable. I prefer an elongate log suitable for the snake to completely conceal itself. Like most snakes, Lystrophis are thigmotactic and feel most comfortable when they are in contact with their environment. Therefore, a hidebox or a log which conceals and covers the snake, but which is not too large, is the most suitable for these types of hognosed snakes.

TEMPERATURE

Temperature requirements for all four species of the Neotropical Lystrophis range from a daytime temperature of the mid 70’s to the mid 80’s, and a nighttime temperature of the mid to high 60’s. Lystrophis are thigmothermal (require contact with warm surfaces). A basking light is useful and if placed at one end of the enclosure, provides a thermal gradient.

To create a warm gradient within the enclosure, the keeper should provide an under-surface heat mat at night set on a timer; this permits the snakes to move onto or away from a warmer surface at night. Warm temperatures are important in maintaining optimal health by aiding in digestion, fighting disease, and facilitating growth and hormone development.

A word about heat rocks – don’t use them! More fires and animal injuries occur from these types of heaters than any other product. Snakes lack sensitive nerve endings along their ventral surface and therefore are unable to detect high temperatures on surfaces. Since the heat radiates from a rock surface independent of the air and surrounding temperatures, snakes have difficulty recognizing heated surfaces that might cause injury. Instead, heat pads placed beneath an enclosure with more moderate temperatures will provide a safer environment.

PHOTOPERIOD

South American hognosed snakes, like other animals, require regular day and night cyclical periods to function normally. While a day/night photoperiod of 12 and 12 can be provided with effective results, varying the daylight and dark periods to mimic nature provides a more realistic setting and may contribute to a more successful breeding program. Timers which turn lights on and off can be had for very little or, for more precise and more reliable models, quite a bit more.

Digital timers can also be built into a room to turn on and off lighting, heat pads, and misting systems.

HUMIDITY

Humidity levels for Neotropical Lystrophis approximate that for American Southern or Madagascan hognosed snakes. A humidity level of 30% to 50% sufficient for most of the Neotropical Lystrophis clan. Humidity is also important for maintaining respiratory health and to facilitate shedding. When these snakes go into blue, it is helpful to simply pour water onto the substrate (such as newspaper) or increase the humidity of the moss or bed a beast.

FEEDING

In the wild Neotropical Lystrophis feed primarily on small insects and lizards as neonates and then on toads and lizards as adults. It is thought they may also consume small rodents as well. In captivity, all members of Heterodon, Leioheterodon, and Lystrophis can be trained to accept rodents through prey-scenting. There have been no studies conducted to determine the effects a mice diet has on these species over their lifespan.

Neonate Neotropical Lystrophis may be fed one or two small pinkie mice per week; this is sufficient to maintain a healthy weight. Many breeders and herpetoculturists overfeed young snakes in the hopes of having them reach a larger size more rapidly. This can result in obesity problems later on. It is better to feed snakes enough to keep their weight at a steady growth rather than have them grow too fast. By the same token, intentionally stunting animals by feeding them too little (as is done with some boas and pythons) can also cause serious physical damage.

Typically a neonate Lystrophis should be fed one pinkie each week for the first six months and then 2 pinkies per week for the next 6 months. As the snake grows older and increases in size, you may increase the size of the food item. As an adult, an Argentine Lystrophis may be offered 2-3 adult mice every two to three weeks.

Snakes should always be fed mice that, as a minimum, have been stunned or prekilled. The reason for this is multifold: snakes that do not immediately attack and eat a prey item may be subject to gnawing by the mouse resulting in serious injury. Also, a live mouse grabbed at midbody may be able to inflict a serious bite on the snake. Lastly, it is much more humane to feed prekilled mice to the snake.

Generally I would suggest feeding mice that have been prekilled, frozen and then thawed. Feeding thawed mice also reduces the likelihood of parasite transmission. Ensure you COMPLETELY thaw the mice prior to feeding the snake, if you don’t the partially thawed food item could cause severe gastric distress and kill the snake. Prior to feeding the food item to the snake, pinch the belly of the mouse ensuring it is at least room temperature.

Using a pair of forceps, offer the snake the thawed mouse (A note of caution here: NEVER thaw a mouse in a microwave oven) either in the enclosure or in a special container specifically used for this purpose. Remember to wash your hands prior to and after offering food; this will reduce the chance of a stupid feeding error (SFE). While there have been no instances of envenomation by Argentine hognosed snakes, reducing the risk of a feeding-related bite is safest.

When feeding neonates, pinkie mice may be scented with lizard or toad scent. This is especially important with South American hognosed snakes that feed on lizards, toads, and small rodents. According to successful breeders, after a time, Neotropical hognosed snakes will take unscented mice. Rubbing a pinkie mouse with toad paratoid gland mucous or toad urine will usually be enough to get the snake to feed. WARNING: only South or North American bufonids or treefrogs should be used; other frogs and toads (such as firebelly toads and dendrobatid frogs) may cause death or injury.

If the young hognose refuses to eat toad or lizard scented mice, the pinkie can be split-brained; this smell sometimes entices reluctant snakes to feed. Occasionally young snakes can be placed in a small container with the food item in a dark quiet place and they will feed on their own.

You may create a frog or toad slurry to use as a scenting material for pinky mice. While this has been shown to be most effective with Eastern hognosed snakes, the procedure works well for any hognose that refuses food. Take a couple of toads or frogs that have been prekilled and then frozen for two weeks to kill parasites, place them in a blender with a little water, and blend away! (Be sure to get your parent’s or spouse’s permission first – and don’t tell any houseguests). Pour the mixture into ice cube trays and freeze. Next time you feed your hognose, thaw out a cube, soak the pinky mouse in the mixture and then try to feed the snake. As a substitute, the mixture can also be poured into a water dish. This process can also be performed with lizards.

As a last resort, you may have to force-feed your charge until it begins feeding on its own. This can be a potentially dangerous maneuver and if you feel uncomfortable attempting to force feed the snake, have a qualified veterinarian perform the procedure.

Initially, a vitamin supplement such as Nutrical can be used to build strength and provide necessary nutrients. For a neonate, 5cc of Nutrical every two days is sufficient to maintain health. This can be supplemented with mouse legs and lizard (Anolis) legs coated with Nutrical to facilitate the feedings. Do not use metal tweezers or forceps to force the snake’s mouth open; this can result in severe damage to the snake’s mouth, glottis, or jaw. Instead, use a flat toothpick to gently pry open the young snake’s mouth, slowly insert the syringe (without the needle) approximately a third of the way down the throat of the snake, expelling the Nutrical into the snake’s stomach.

A pinkie pump, which liquefies pinkie mice, can also be used to introduce complete animals into a snake’s stomach.

Force-feeding adult snakes generally requires two people. Coating the food item in Nutrical will also facilitate the feeding procedure. Using a wooden nail file or Popsicle stick, gently pry the snake’s mouth open. Insert the food item, head first, into the snake’s mouth. The snake’s head will have to be held very carefully to prevent injury, while gently forcing the mouse farther down the snake’s throat. The snake may initiate a feeding response automatically. Otherwise, you may have to continue to apply slight pressure to the snake’s jaws while massaging the snake’s neck so the mouse proceeds down the snake’s throat. If you are unable to move the food item far enough down the throat, the snake may regurgitate the item and potentially risk injury.

Of course, all keepers know that there are some snakes that simply fail to thrive and never take food in captivity. In the wild, these snakes would simply wither and die. In captivity, you may be forced to force feed these snakes for many years. In the end, only you can decide if keeping the snake merits the risks, or if the risks outweigh the benefits.

BREEDING

Most hognosed snakes reach sexual maturity at two years of age in captivity; due to a lack of available data it remains unclear if this is true with Neotropical Lystrophis or not. Sexual maturit ymay be more dependent on length than age as is true with many reptiles. Once mature, a female can be introduced into a male’s enclosure for breeding. By introducing the female into the male’s enclosure, it will be easier for the male to follow the pheromones (sexually induced scent gland chemicals) and locate the female. Many snakes have bred successfully despite being kept together year round.

Wild caught snakes generally require two years to completely adapt to a captive environment. Although younger snakes will adapt more readily and more quickly, some wild caught adults may never adapt at all. The comfort level of the snakes is critical to successful captive propagation.

While information on wild individuals is sparse, Argentine Lystrophis have been observed to lay eggs from August through October depending on the region and temperatures. Not enough studies have been done to provide data on the number of eggs that are typically laid by Lystrophis in the wild.

I do not have any data on the number of eggs or clutches of Lystrophis histricus in the wild or in captivity. Extrapolation of data from Lystrophis tricolors may suggest they lay 6 to 12 eggs per clutch. More studies on this subject are needed for better understanding.

Prior to the female laying her eggs, you should prepare a suitable nesting box with a vermiculite/water mix. A plastic shoebox half-filled with moist vermiculite, on a 1:1 ratio of water to vermiculite, measured by weight is most commonly used. To increase the likelihood the female will enter the box, cut a hole in the top of the box through which the female can enter and exit easily. Be careful not to leave any sharp edges that may result in cuts. Place the shoebox in the portion of the enclosure that has the most constant temperature, preferably away from the basking light. With any luck, the female will seek out her nesting site and lay eggs just after a pre-parturition shed.

INCUBATION

Once the eggs are laid the box should be placed in an incubator. An “incubator” can be constructed on cabinetry type materials, an aquarium or other suitable enclosure. A temperature range of 82 to 84 degrees Fahrenheit appears to be most successful for Lystrophis.

There are many types of incubators available on the market, or you can manufacture your own. The HOVA-BATOR was originally designed to hatch chicken eggs but it can be modified to serve as an incubator for snake eggs. Most backyard breeders simply make their own incubators out of old refrigerators, cabinets, or aquaria. As long as there is little temperature or humidity variance, the eggs should do well.

Occasionally if eggs are not transferred soon enough or become desiccated (dried out) they may seem to cave in. Once the humidity levels are elevated the egg may regain its shape and hatch normally. Other eggs, due to mishandling, infertility, or rapid temperature changes may collapse, develop mold and turn yellowish. These eggs should be separated from viable eggs and discarded.

During the course of incubation, you may carefully examine the eggs, using a process known as “candling.” When candling eggs, be sure not to rotate the eggs because the embryo may become detached from the wall of the egg or the yolk may rupture or smother the embryo. To candle an egg, hold the egg with the thumb and forefinger of one hand while shining a flashlight from behind the egg with the other hand. If the egg is fertile, you should be able to see blood vessels developing within the yolk and the dark eye spot of the embryonic snake.

Check the eggs periodically to ensure they are not rotting or covered with fungus or mold. Because the shells are permeable and exchange moisture and oxygen vital to the survival of the embryo, no chemicals or toxic substances should be used on the eggs during development.

Typical incubation for Argentine Lystrophis is from 60 to 80 days depending on temperature and humidity. When born, Lystrophis histricus are approximately 4 inches long with adults averaging 14 to 24 inches depending on the sex and the species.

BRUMATION

Brumation is the period of inactivity snakes in temperate regions undergo prior to emerging and mating. While brumating, snakes experience limited activity and may not be completely unconscious. It is generally agreed that most snakes must undergo a period of inactivity during the colder winter months to rebuild their strength and prepare for the upcoming mating season. Although the region in which Lystrophis are found ranges from windswept pampas to subtropical in nature, during the winter months, temperatures in the region may drop to the low to mid fifties (50 degrees Farenheit, 10 -14 degrees Centigrade), brumation for Lystrophis is also recommended.

While some keepers insist that snakes must be brumated for them to breed successfully, others have successfully bred South American hognosed snakes with no brumation whatsoever. Trial and error may be the best approach: if the snakes breed successfully without brumating, there should be no reason to brumate them. Long term studies are needed to determine if brumation is critical to extend the life and improve the health of Lystrophis.

To brumate Argentine and Brazilian Lystrophis, feed them heavily a month ahead of time. This will prepare them for the two to three month period when they do not have access to food. After you observe that the snakes have defecated, do not feed them for another two weeks, this will allow them to completely clear their bowels. If the snakes are brumated with undigested food in their gastrointestinal tract, the food will decay and cause death.

Brumating snakes at the appropriate temperature is extremely important. If kept too warm, bacteria and parasites in the snake’s system could remain active. Since the snake will have been placed in a state where its immune systems have been lowered, it may fall victim to disease or infection that they would normally be able to fight. If a snake is kept too cold, they may unable to recover from their state of torpor.

The suggested brumation temperature for Neotropical hognosed snakes is between 50 and 55 degrees Fahrenheit. While some keepers suggest gradually dropping the temperature over several days, there is evidence to suggest that this may result in respiratory infections and an overall reduction in the immune system of the snake. Instead, once the snake’s digestive system has cleared, it can be placed into a container at the appropriate hibernating temperature.

A suitable brumating container may include Styrofoam boxes, Tupperware containers or the snake’s normal enclosure. A substrate such as newspaper or CareFresh bedding should be placed in the “hibernaculum.” Because brumation differs from hibernation in that brumating animals remain active, you should also provide a hide box and a water dish filled with fresh water. Snakes will seek water during their brumation period. Since you have already been altering the photoperiod (as discussed earlier) to coincide with the seasons, the snakes will be ready for full brumation.

SUMMARY

Owing to their rarity in captivity and their protected statues, it is unlikely that most hobbyists will encounter Lystrophis histricus or Lystrophis nattereri. Generally speaking, these animals can be maintained in an environment that mimics their natural environment. Small enclosures with suitable substrate will often suffice for most adults. The most difficult aspect of husbandry will likely be getting a wild caught specimen to feed on domestically produced mice. Through prey scenting this obstacle can usually be overcome. The temperament of most hognoses is such that they will often do fairly well in captivity over their lifespan.

Material copyright 2006 by Dennis Desmond, HerpTech Associates.