Care for Mexican Fire Leg Tarantulas – September 2013

By Anthony Neubauer

Introduction

The group of tarantulas that make up the genus Brachypelma are ideal spiders for any hobbyist. Their generally calm demeanor, decent yet manageable size(5-6 inches), and stunning colors make them perfect for a display animal. Some tolerate handling more than others, but as with any spider, care should be taken when handling. My personal favorite, the Mexican Fire leg, is better kept for display. They are one of the most colorful members of the genus, and tend to stay out in the open for viewing.

When selecting a first tarantula, most people are instructed to start with “New World” species, that is, species that come from North or South America. New World species possess specialized hairs on the abdomen, called uriticating hairs, that are rubbed off as the first defense. These hairs, once airborne, cause itchiness and irritation. Some people are more sensitive to them than others, but they generally are of little worry. Because they possess these hairs, they are less inclined to bite, and possess less potent venom if they do. They also tend to be calmer and slower moving. This makes them more manageable for the beginner and intermediate hobbyist. The Brachypelma genus hails from Mexico and Central America, so fall into the New World category.

Selecting an Enclosure

When selecting an enclosure for a Fire Leg, one must keep in mind that they are a terrestrial species, so will spend their time on the ground. This is important, as housing them in too tall of cage can result in a fatal fall. Spiderlings are available as small as half an inch, and up until around two inches should be housed in a small, simple setup as locating their food and water will be tough in larger enclosures. I recommend an eight ounce deli cup up until two inches such asthis. Once they start gaining size, appropriately sized glass tanks or plastic enclosure can be used. For an adult Fire Leg, something with similar floor space to a 10 gallon tank is sufficient. Exo Terra Breeder Boxes and Flat Den Homes are an excellent way to save space, allowing for you to have more spiders!

Cage Décor and Substrate

For any tarantula to thrive, a hiding spot should be provided to allow the spider to feel secure and keep stress levels down. Hides can be anything from a coconut hide, to a piece of cork bark, to a stone cave or skull. Basically anything they can get under or in, and be mostly unseen. Commonly used substrates include Coconut Husk, Orchid Bark, and Cypress Mulch. A water bowl should also be offered for spiders around three inches and up. It should be shallow enough that there is no risk of drowning, and should be changed every couple of days to keep it clean. Spiderlings up until three inches should be sprayed once a week, and not given a water bowl, as this can cause drowning. They will drink the water droplets when they are sprayed. It is not recommended to use a sponge as a water source, as these quickly promote bacterial growth. Some keepers, particularly those interested in keeping Fire Legs for a display animal, choose to take the habitat to the next level and create a natural living vivarium, complete with live plants. This can be easily done with a little extra thought and consideration.  Keep in mind your tarantula’s needs when molting (higher humidity in particular), and you can recreate a desert- style vivarium with moist hiding areas.

Temperature and Humidity

Fire Legs come from the deserts and sub deserts of Mexico. However, no tarantula should be kept constantly dry or too hot. They can be kept at room temperature in most households, provided it stays around 70-73*. Ideally you’d be shooting for 78-80 Degrees, in which case they will metabolize and grow quicker. If you need to pump the temperatures up a little bit, you can use a Clamp Lamppointed at one side of the cage to raise the ambient temperature.

Heat pads can also be used, but should only be mounted to the side of a glass enclosure, as tarantulas burrow to escape heat, so an undertank heater would result in a cooked spider.

As adults, their substrate can be kept bone dry as long as a water bowl is provided. They should also be given higher humidity before they molt. This is achieved by lightly spraying the enclosure, and by adding wet Sphagnum Moss.

Feeding

Tarantulas in general have a low metabolism. They aren’t running around the cage all day, or doing much of anything, to be honest. As a result, they don’t eat a whole lot. Most spiders will eat one appropriately sized insect a week. Spiderlings can be offered Flightless fruit flies if they are too small to tackle live crickets. They can also be given a freshly killed small cricket, as they can be scavengers for their few months of life. It is not uncommon for your tarantula to skip a meal, or even go for a prolonged period of fasting. As long as they maintain a plump abdomen, they are perfectly fine. The most frequent reason that a spider refuses a meal is that is going through premolt, that is, it is preparing to shed its skin. Signs of premolt would be the tarantula kicking all of its uriticating hairs off, leaving a light colored bald spot that eventually turns black. After the process is complete, you will find a shed skin that looks just like your spider! They will also begin to regenerate legs during this time if any are lost.  Leg regeneration can take several molts and can be a complicated process for your tarantula, so while they can regrow their legs, it’s best that they not lose them in the first place.

Sexing

Sexing tarantulas is usually difficult until they mature. Once mature, males will possess “hooks” on their pedipalps, which are used for breeding. Once males “hook out”, they will only live for another year or two. Females will not get these hooks, and will instead live for around 20 years after maturing. This obviously makes females more desirable to acquire, however it is near impossible to tell until they are mature.  You can also sex tarantulas by examining their molts closely, but as this can be difficult without the right tools to see the right parts in a tiny spiderling molt, to be truly accurate it is best left to the dedicated tarantula enthusiast.

Conclusion

Overall, the Mexican Fire Leg Tarantula makes a perfect pet for beginning and advanced hobbyists alike. They are very hardy and easy to care for, but attain decent size and amazing color. They are not very quick, nor are they very bitey, but they do kick hairs and become nervous when disturbed, so they are better left as a “look-but-don’t-touch” pet. They can be kept in a simplistic setup, or in an elaborate vivarium. Either way, they will thrive as long as a  few basic needs are met. If you are looking for a colorful tarantula that is easy to deal with and maintain, stop looking and purchase a Mexican Fire Leg Tarantula!

 

The Chaco Golden Knee Tarantula – March 2013

By Shawn Bowman

Grammostola Pulchripes

Have you ever been curious about owning a tarantula for yourself? The Chaco Golden Knee Tarantula is an excellent choice for a first time arachnid due to its mild temper, low maintenance, and large size!

There is no doubt about it; tarantulas are one of the lowest maintenance pets you can have!

Gold knee tarantulas are a burrowing species so deep bedding is suggested.

A five gallon enclosure with 3 to 4 inches of bedding will be used if provided.

Any of the coconut beddings such as Eco Earth or Plantation soil will work well. Some keepers choose to mix in bark or vermiculite.

Keep the bedding fairly dry with a weekly misting. A small water bowl can be provided however most spiders are okay with occasional misting and food items as their water source.

The spiders should be fed an appropriate sized prey item once or twice a week. Depending on the size of the tarantula, this can range from a fruit fly to large crickets. It is important not to feed more crickets than the tarantula will be eating.  If crickets die in the tank the natural mites a cricket carries will multiply, and the large number of mites can eat your tarantula while molting. That being said, one large, easy to catch prey item is usually better than multiple small prey items.

Why a Chaco over another species of tarantula?  The size is what’s cool about these arachnids.  They are generally as docile as their relative, the Rose Hair Tarantula. It gets a leg span that reaches up to 8 inches making them one of the more impressive large tarantulas that could be considered a beginner species. The female spider can live as many as 20 years with male spiders averaging a lifespan of about 3 years.

When looking to handle your tarantula, keep in mind each animal is going to act a little different. I suggest getting your tarantula at a small size because this species is usually not aggressive as a spiderling and is typically very easily handled. This will help build your confidence and understanding of the tarantula before it attains its full size. Keep in mind that they can bite if they feel threatened.  Slowing  down and reading the signs of your spider is the best way to keep yourself out of danger and keep your tarantula happy!

Dangerous Discussions: Part Two – November 2012

The Reptile Times

By Kevin Scott

In Part I of Dangerous Discussions I gave an overview of the definitions of and differences between poisons, toxins and venom. In Part II, I will go into greater detail in describing what toxins and venoms are and where they occur in nature. Of course, it would be impossible to talk about more than a handful of occurrences, so I decided to choose those that I find most interesting.

Toxins

Toxins are organic molecules that are produced via biological pathways and are often used as defense mechanisms by animals. As mentioned in Part I, amphibians secrete substances that are toxic to bacteria and fungi, as the external part of their immune system. Some amphibians also secrete substances that are toxic to predators in order to prevent becoming prey. Tomato frogs and toads, for example, secrete thick milky substances that serve as irritants to potential predators. Arrow Frogs, as discussed in Part I, also secrete toxic compounds, these often being far more toxic than any produced by other amphibians.

The most potent of these toxins are steroid alkaloids, but nearly all of them are neurotoxic. Batrachotoxin is the most toxic of these, but other common compounds include epibatidine, histrionicotoxin and pumiliotoxin. If you are familiar with the arrow frogs, you can see the names of a few species in the names of these molecules. Batrachotoxin targets sodium ion channels, while epibatidine and histrionicotoxin target nicotinic acetylcholine receptors, and pumiliotoxin targets calcium ion channels.

Some, but not all, of these substances are actually produced by the frogs themselves. Many of the more toxic compounds, however, are actually produced downstream in the food chain. Pyrrolidines like epibatadine, and piperidines that are present in species found in the genera Oophaga and Ranitomeya, and Ameerega, Dendrobates and Ranitomeya (Lötters et al 2007), respectively, come from the ants that they eat.

Being that invertebrates and plants are the sources of these toxins, it is not surprising that it is not only the arrow frogs that possess them. Mantellas, the Arrow Frog’s Malagasy counterpart in terms of parallel evolution, also possess some of these toxins. One advantage of the fact that these frogs get this defense from their food items is that they are not nearly as toxic in captivity as they are in the wild.

Another frog that we commonly see in captivity, the Fire Walking Frog (Phrynomantis bifasciatus), also has toxins that can be used as a defense toward predators. This toxin’s identity is not known, but wild caught specimens can cause a burning sensation on the skin of a human, and it is strong enough to cause cardiovascular arrest in other frogs.

fire walking frog

The fire walking frog secretes a substance that can cause intense burning sensations in humans, and death in other amphibians.

Venoms

There are many animals that produce venoms, including spiders, scorpions, marine invertebrates, fish, snakes, lizards and even mammals. Of these, a good handful can be found in the reptile industry.

Venoms are made up of mixtures of low-molecular-weight proteins, mucus, salts and organic compounds that include oligopeptides, nucleotides and amino acids (Colis 1990). This mixture can serve a variety of functions that include defense, prey submission and pre-digestion. Some of the types of venom are as they follow: neurotoxins cause neuromuscular paralysis that can result in immobilization and death; presynaptic neurotoxins block the release of the physiological transmitter acetylcholine, destroying the nerve terminal, and postsynaptic neurotoxins competitively inhibit binding of acetylcholine, preventing the transmission of nerve impulses across the synaptic gap; haemotoxins destroy red blood cells, and extreme cases can lead to renal failure; myotoxins damage muscles, especially respiratory muscles; cytotoxins destroy tissue, and these can aid in pre-digestion; nephrotoxins damage the kidneys (O’Shea 2005).

While the toxins that we have discussed in frogs are passively delivered, venom is delivered with an active delivery system. Special apocrine glands are connected to or in the vicinity of specialized hollow teeth or fangs, grooved teeth or a stinger (in the cases of the reptiles, tarantulas and scorpions that are common in the industry) that act as a penetration device that allows the venom to be administered.

vine snake

The fang of this vine snake can be seen within the red patch of gums behind the eye.

The most advanced delivery systems utilize fangs as an application mechanism. These fangs are specialized hollow teeth, through which the venom is delivered. These are used by vipers (including rattlesnakes) and elapids (including cobras, sea-snakes and kraits). Vipers have long, movable fangs that can be used to alternately progress, ‘walking’ a prey item down during feeding. When not in use, these fangs fold inward, allowing the mouth to close. Elapids are also front-fanged, but they generally have shorter, fixed fangs.

Only relatively few colubrids are venomous, but the ones that are have grooved teeth toward the back of the skull, which is known as being rear-fanged. These teeth are located below or behind the eye socket, and below a specialized salivary gland know as a Duvernoy’s gland, which secretes a toxic saliva that is used in subduing prey (O’Shea 2005).

While they may outwardly appear similar, the fangs of a tarantula or centipede are actually not teeth at all. Rather, they are chelicerae. Chelicerae are pointed appendages that are found in all members of the subphylum Chelicerata, that are used for grasping food or for defense. In spiders and venomous myriapods the chelicerae are hollow, and are used to inject venom from the connected venom gland.

fangs

The chelicerae of tarantulas, spiders and centipedes can be quite large, and are used for grabbing and envenomating prey items, as well as for defense purposes.

Scorpions have a pretty unique venom delivery system known as a telson, or stinger. At the end of the tail, a specialized anatomical development contains both the venom gland and the sharp point used for injection.

scorpion

The telson of a scorpion contains the venom gland and delivery system in one specialized evolutionary development.

Conclusions

Although there are many other animals that are capable of delivering venom and the systems with which venom is delivered are far too complex to discuss in any depth here, I hope that the topics discussed here were enlightening. Furthermore, I hope that the content was deep enough to hold the majority of the readers’ attention, but straight forward enough so that no reader was excluded due to complicated writing.

O’Shea, Mark. 2005. Venomous Snakes of the World. Princeton: Princeton University Press.

Polis, Gary A. 1990. The Biology  Of Scorpions. Stanford: Stanford University Press.

Lötters, Stefan, Karl-Heinz Jungfer, Friedrich Wilhelm Henkel and Wolfgang Schmidt. 2007. Poison Frogs: Biology, Species and Captive Care. Frankfurt: Edition Chaimaira.

Entomological Etymology – Correction

ENTOMOLOGICAL ETYMOLOGY

CORRECTION
By Kevin Scott

In the last issue of The Reptile Times, the spiders belonging to the genus Poecilotheria were erroneously referred to as ornamental baboon spiders. Baboon spiders belong to Harpactirinae, a subfamily of Theraphosidae(tarantulas) from Africa. This subfamily was first set up by Reginald Pocock in 1897 to include species in the genera Ceratogyrus and Pterinochilus [1].  The accepted common name for the Poecilotheria genus is simply “ornamental spiders,” excluding the word ‘baboon.’ The scientific names used in the last issue were correct as of the date published.correction

NOMENCLATURE

In the world of invertebrates, it is particularly important to use correct nomenclature in order to avoid uncertainty with respect to a species’ identity. Stanley and Marguerite Schultz claim that the nomenclature of tarantulas “can euphemistically be described as confused,” in their book The Tarantula Keeper’s Guide. Much of the confusion stems from misidentification during importation as well as the misuse and misspelling of names. I generally prefer to use the scientific names of spiders to avoid confusion, but even so, there can be some uncertainty in terms of the most common revision of classification.

COMMON DESCRIPTORS

One problem with common names is that they are often descriptive, and could in principle apply to several species. For example, Nhandu coloratovillosum is commonly referred to as the Brazilian black and white tarantula. Acanthoscurria geniculata is also a tarantula from Brazil that has black and white coloration, but the common name for this one is Brazilian giant white knee. Furthermore, although these two species are far from identical in appearance, to someone with little or no knowledge about tarantulas, they can appear similar to one another, especially as spiderlings.FINAL NOTES

In all fields of science, nothing is 100% exact, and taxonomy is good example of this [2]. Scientists often argue about the classification about species and whole genera are taken apart and reassembled based on new information all the time. Advances in genetic analysis allow us to take a closer look at the relationship between life forms, often with surprising results. Because we live in a world where things are constantly changing, where ranges of inhabitance overlap, and where interspecies breeding can occur, the field of taxonomy will probably continue to change indefinitely. In addition, even within a species differences in physiology can be seen. With a conscious effort to use correct nomenclature we can all remove a portion of the error, at least where science and hobby overlap.

[1] For more information on baboon spider taxonomy and descriptions, see www.BaboonSpiders.de

[2] For more information see Robson, G. C. (1928). The Species Problem: an Introduction to the Study of Evolutionary Divergence in Natural Populations. Edinburgh: Oliver and Boyd.

Poecilotheria in the Vivarium

Poecilotheria in the vivarium

By Kevin Scott

WARNING: The species of Poecilotheria described here are spiders that can be fast, aggressive and extremely dangerous to humans. They should NOT be handled.

VIVARIUM ORNAMENTS

Over the last decade or so there has been an explosion in vivarium popularity. Animals like arrow frogs, mantellas, day geckos and other small diurnal herps are a natural choice for such display cages because of their distinctive coloration and visibility during the day. Tarantulas and bird spiders have been largely neglected in this department, and not without reason. Most spiders are secretive, and will either bury themselves or spin thick, opaque webs, making it difficult to observe them. Either way this makes them difficult to be seen. In addition, most tarantulas will eat almost anything else that they are housed with.

fringed ornamental

The Fringed Ornamental Baboon Spider (Poecilotheria ornata)

Species of the genus Poecilotheria (Ornamental Baboon Spiders), however, can often be seen sprawled on pieces of wood or cork bark. While they cannot be housed with other animals (although they have been successfully kept communally), Poecilotheria species can make an unusual and decorative addition to the tropical vivarium.

CARE

Ornamental Baboon Spiders are from tropical South East Asia (India, Sri Lanka) and benefit from moderate to high humidity (50-75%), although they can go for extended dry periods if needed. Light daily misting is recommended if your vivarium is not humid enough from moss and/or plants that are established within it. As with humidity, heating situations can vary widely depending on the style and orientation of your vivarium, but a thermogradient with the warm side reaching temperatures of 78-80 degrees is recommended. Compact fluorescent lighting commonly used for vivaria usually emit sufficient heat for Ornamentals (although they normally shy away from bright light) but if this is not enough, an under-tank heater can be used as asecondary heat source.

vivarium

A simplistic arboreal vivarium with a hollow piece of grapewood is ideal for any of these species.

Again, each vivarium is different and care should be taken with tropical plants when selecting a spot for a heat source.

Being arboreal (tree-dwelling) animals, Poecilotheria species prefer vertically oriented vivaria. Adequate ventilation should be provided. Although they are often seen ‘out and about,’ hide spots are necessary. Cork hollows are ideal for this, and will allow your spider to build a web to retreat to, should it want to. Live plants with broad leaves, like pothos ivy, smaller philodendron and bromeliads, also provide excellent cover in this type of environment. A small water dish with a sponge or cotton balls should be offered, for your spider to stay hydrated.

indian ornamental

The Indian Ornamental (Poecilotheria regalis)

FEEDING

All Poecilotheria species can feed solely upon crickets. Spiderlings and adults alike can feed weekly, with the size of the food item ranging from small to large crickets, as is appropriate. Care should be taken to provide enough food if a communal vivarium is what you have in mind. Although Ornamentals have been successfully kept together (same species, same size only), they have also been known to cannibalize. If you set up a communal vivarium, it is essential that you provide enough food for your spiders. Several appropriately sized crickets should be fed to each spider weekly, with uneaten food items being removed from the cage with tweezers. Other food items including cockroaches, locusts, meal-, super-, and wax-worms can be fed as well, but in the vivarium these have a tendency to hide or dig if not captured immediately.

CLOSING COMMENTS

In closing, I would like to note that species of Poecilotheria are not the only spiders that do well in vivaria.Brachypelma species are another excellent addition to the tropical vivarium. These terrestrial counterparts are very hardy and less aggressive than the Ornamentals, and are readily available in the pet trade. Brightly colored and not as reclusive as some other tarantulas, these fascinating animals are a subtler main feature than brightly colored frogs or geckos, but if you take the time to set up and care for these eight-legged wonders I think that you will be pleasantly surprised.