BLS Blondi
11-21-2006, 03:05 PM
As far as we know, Theraphosa blondi, native to Venezuela, northern Brazil, Guyana, French Guiana and Suriname, is the largest species of tarantula on the planet today—which I whole-heartedly agree with. Being a keeper of tarantulas for years, I have always favored this species due to their massive size. First and foremost, there are those who say Lasiodora parahybana are just as large and even Theraphosa apophysis has been mentioned in the “largest spider” category. But on a consistent basis, and through rearing hundreds of the three aforementioned species, Theraphosa blondi is the largest by species and by its individual specimens. That is not to say that there aren’t exceptions. Nature will always have exceptions, as I have had a few “freaks” myself. What I plan to achieve in this essay is to help those interested understand this species much more—and to give explanations as to why certain characteristics exist.
Why does T. blondi get to be so big? Many reasons. Genetics--first and foremost. I am not a scientist, nor do I claim to be, but genetics play a huge role. Secondly, this species can eat a lot of food. The more food they eat the bigger they are. Makes sense so far, right? Secondly, a “newer” theory (a guess, rather) that I have is due to its environment. Did you ever stop to notice that lower-level animals on the food chain are much bigger in South America? Invertebrates, snakes, certain amphibians, etc. get much larger. Now there is no supporting evidence or any concrete facts, but then again, that territory, including the rainforests and its inhabitants have been barely touched as far as scientific research is concerned. There are other theories that plants there may have cures for human diseases, but so little has been done to find out. One thought that comes to mind is the role oxygen and humidity play in the metabolism of a T. blondi. Oxygen we know is extremely important not only to survive, but for a proper metabolic rate, but these areas where T. blondi inhabits do in fact have a higher oxygen concentration than, say, North America. Also, this is the supporting theory followed by scientists on why the fossil spider “megarachne” was even bigger. There was a much higher concentration of oxygen in the air, allowing this species to get much larger. So, if this is true, then the opposite is also true—the lower concentration of oxygen in today’s atmosphere limit the size of T. blondi. Of course, the law of increasing entropy also plays in effect, but is it possible that a perfect environment for a T. blondi could create specimens that are 24” long?
Tarantulas are living fossils. Their breathing apparatus (book lungs) have not evolved. Hence, they are inefficient in today’s atmosphere. As I mentioned before, millions of years ago, the Earth was warmer and much more humid. Not to mention the increased percentage oxygen in the air, thus the book lungs were all it needed. As Earth’s atmosphere changed throughout the millennia, tarantulas survived due to their instinct, which disallowed evolution in a sense. The reason why T. blondi is much more affected by this is due to their massive size. Their book lungs simply cannot be efficient enough to keep that whole body oxygenated enough when they get 8" and bigger. Also, this seems to be the reason they do not keep growing and growing. Less oxygen = slower metabolism. This is evident in the fact that most adult T. blondi (in captivity) die during molts. They become way too exhausted to get out. This is a theory I have had for years, which is now supported by many tarantula keepers. Book lungs also need high moisture for gas exchange. With out the moisture, the book lungs dry up, and if really dry, the T. blondi will die.
Some other questions I have been asked numerous times over the years is: “Why do T. blondi (as well as many other species) eat their eggs? Why is it so hard to get a good egg sac from a T. blondi in captivity?” The truth is, no one knows. There are educated guesses, but no fact. Charles Darwin touched on this subject in his book (perhaps you’ve heard it before? lol) Origin of the Species. Early in the book he inquires about how it is very hard to breed certain animals in captivity. He didn’t get much past the thought that it is hard for man to completely re-create an animal’s habitat, and somewhere parts of the life cycle become lost. In all of my T. blondi keeping and breeding, there still remains a high failure rate of producing a good egg sac. This obviously seems counter-intuitive since invertebrates survive (avoid extinction) simply by producing large numbers of offspring very frequently. If invertebrates in the wild produced the same amount of offspring they do in captivity, these species would surely be extinct by now. So what is different? For all tarantulas, Darwin’s theory about captivity is definitely correct somehow. But for T. blondi, it is this theory plus a new idea: they are much more sensitive to environmental changes than other species. What do I mean by this? I have been able to mate Brachypelma smithi with ease. I have gotten good egg sacs consistently regardless of the environmental changes. I use to keep B. smithi in room temperature and whatever the humidity was in my house at the time. I have had success getting egg sacs any time of the year. I have since moved them into my “spider room” which is built and maintained for T. blondi. This room (not just the cages) is 75F and humidity is 80%. I still get good egg sacs from B. smithi. This is also the case for various Avicularia species and Psalmopoeus species as well.
But in the past few years, I have traded and sold off most of the species and now keep T. blondi, Xenesthis immanis, and Pamphobeteus spp. exclusively. I currently have over 30 T. blondi of various ages and sizes. Two of my adult females are quite old. One of my females (and the biggest) is at least 9 years old now. She currently is just a hair over 10.5” measuring from Leg I to Leg IV of the same side. As much as it pains me to admit it, I bought her as a juvenile over 8 years ago as a wild caught female. My second largest female is also a wild-caught, which I bought 6 years ago. (Note: I bought many wild caught T. blondi years ago, and I do not buy wild caught anymore, nor do I condone it—as it is cruel and they usually do not do well in captivity). Ever since these purchases, I stopped buying wild-caught tarantulas, as soon as I found out how they are collected from the wild. Getting back to the point, I have realized that the wild-caught T. blondi (when they survive in captivity), do get larger than those specimens that were reared in captivity. In particular, I noticed that the average carapace size of the wild-caught specimens is consistently larger than those of captive bred specimens of the same leg span. Here is another difference: on average, wild caught specimens are much more prone to hair kicking (and do it for the slightest disturbance), yet are much more responsive to mating.
Another factor that is in play here is diet. Many captive-bred T. blondi are fed crickets. The crickets that are sold in pet stores are commonly known as the European grey cricket. These insects are not found in South America. T. blondi in the wild will never see one. They eat rodents, snakes, native invertebrates, frogs, and the like. So perhaps the difference in their diet plays a factor in their metabolism, overall growth, and their ability to produce good offspring. We see the difference in human beings as well. As food and water quality has improved, so have our lives. “You are what you eat” definitely holds true.
So what is the “correct” way to take care of a T. blondi? The requirements in captivity are rather simple. First off, the cage for an adult should be at least 24w” x 12h” x 12d”. Substrate should be at least 5” deep to hold moisture. The substrate can be a mix of vermiculite, peat moss, coconut peat, and topsoil. It has to be pesticide free (duh) and be able to hold moisture to keep humidity relatively high. They require humidity levels of at least 70%, yet at the same time must allow fresh air in the tank. Stagnant air causes a moldy tank and can even lead to death. They will also need a large, shallow water dish with water in it at all times. They will also need a retreat to hide in. What I use is artificial retreats from Exo-Terra (large ones) and cut a bigger entrance hole for them. These hides also help keep humidity in its retreat. Decorations are optional, and if you must, I would recommend live plants to help increase humidity and oxygen levels.
As far as feeding is concerned, feed them well. These are animals that can get very big, so they need the food. I can’t begin to explain how many times I have received mature males or adult females that were tiny. The smallest mature male I have ever reared was 8” from leg I to leg IV of the same side. My females get at least this big, many get bigger. I feed mine adult mice, pinkie mice, hopper mice, assorted roaches, silkworms, crickets, snakes (every now and then) with an occasional frog. The quantity is up to the individual, but this species is a hobby favorite due to its size, so why not let them reach their potential?
When it comes to mating, T. blondi is relatively easy to get a good reaction. For those who own Citharischius crawshayi, you know the difficulty in keeping the male alive, let alone a good egg sac. For T. blondi though, it is easy mating. The problem is getting an egg sac that is viable. Throughout my span of keeping T. blondi, the males have always been able to achieve successful insertions. Yet, when it comes to egg sac production, it is a 50/50 chance, and then keeping the eggs with the mother for 30 days without getting eaten or discarded is even harder. First and foremost, T. blondi (I believe) is much easier to mate because the males, if fed properly, get as big as the females. The male has a much greater chance of being able to push her off than a C. crawshayi male. But when it comes to egg production, there is a high percentage of failure. Here is where I revert to Darwin’s thought about [some animals] having difficulty producing offspring in captivity. No one really knows the answer to this, we just know that if an egg sac is produced, your odds of getting a successful hatch is better if you pull the egg sac from the mother and incubate it yourself.
Upon getting a successful hatch, you can expect between 50 and 100 spiderlings each about ¾”-1” long. They appear to be almost a shiny bluish-black color around this size. And boy, will they eat. It is next to impossible to over feed a T. blondi spiderling. They will eat fruit flies, pinhead crickets and other insects of similar size. Humidity becomes extremely important at this stage, because T. blondi spiderlings are even more sensitive than the adults. What also needs to be taken into consideration is that as spiderlings they will molt very frequently, so they need moisture constantly. If fed properly, the female babies should reach 3” to 5” within a year. Males can get even bigger, as I have power-fed many to get on cycle with the females. Power-feeding a male can push him to mature in less than two years. The fastest I have achieved is a male spiderling reaching sexual maturity at 8” in 15 months. Babies should be separated (this goes with ALL species) to avoid cannibalism. How to house them is not important as long as the environmental conditions are met and they are all separated.
The T. blondi is a staple tarantula in any hobbyist’s collection. A tarantula that gets big enough to eat other tarantulas makes them much more fascinating. (Please note I do not condone tarantula cannibalism—I just wish my female C. crawshayi knew this!) As with all tarantulas, they are fascinating creatures and have definitely earned their place on earth. Though they are not as colorful as X. immanis, their sheer size more than makes up for their simple chocolate-brown coloration. Just remember, these giants need proper care, and hopefully within this essay will answer any questions about keeping them and understanding them have now been answered.
Why does T. blondi get to be so big? Many reasons. Genetics--first and foremost. I am not a scientist, nor do I claim to be, but genetics play a huge role. Secondly, this species can eat a lot of food. The more food they eat the bigger they are. Makes sense so far, right? Secondly, a “newer” theory (a guess, rather) that I have is due to its environment. Did you ever stop to notice that lower-level animals on the food chain are much bigger in South America? Invertebrates, snakes, certain amphibians, etc. get much larger. Now there is no supporting evidence or any concrete facts, but then again, that territory, including the rainforests and its inhabitants have been barely touched as far as scientific research is concerned. There are other theories that plants there may have cures for human diseases, but so little has been done to find out. One thought that comes to mind is the role oxygen and humidity play in the metabolism of a T. blondi. Oxygen we know is extremely important not only to survive, but for a proper metabolic rate, but these areas where T. blondi inhabits do in fact have a higher oxygen concentration than, say, North America. Also, this is the supporting theory followed by scientists on why the fossil spider “megarachne” was even bigger. There was a much higher concentration of oxygen in the air, allowing this species to get much larger. So, if this is true, then the opposite is also true—the lower concentration of oxygen in today’s atmosphere limit the size of T. blondi. Of course, the law of increasing entropy also plays in effect, but is it possible that a perfect environment for a T. blondi could create specimens that are 24” long?
Tarantulas are living fossils. Their breathing apparatus (book lungs) have not evolved. Hence, they are inefficient in today’s atmosphere. As I mentioned before, millions of years ago, the Earth was warmer and much more humid. Not to mention the increased percentage oxygen in the air, thus the book lungs were all it needed. As Earth’s atmosphere changed throughout the millennia, tarantulas survived due to their instinct, which disallowed evolution in a sense. The reason why T. blondi is much more affected by this is due to their massive size. Their book lungs simply cannot be efficient enough to keep that whole body oxygenated enough when they get 8" and bigger. Also, this seems to be the reason they do not keep growing and growing. Less oxygen = slower metabolism. This is evident in the fact that most adult T. blondi (in captivity) die during molts. They become way too exhausted to get out. This is a theory I have had for years, which is now supported by many tarantula keepers. Book lungs also need high moisture for gas exchange. With out the moisture, the book lungs dry up, and if really dry, the T. blondi will die.
Some other questions I have been asked numerous times over the years is: “Why do T. blondi (as well as many other species) eat their eggs? Why is it so hard to get a good egg sac from a T. blondi in captivity?” The truth is, no one knows. There are educated guesses, but no fact. Charles Darwin touched on this subject in his book (perhaps you’ve heard it before? lol) Origin of the Species. Early in the book he inquires about how it is very hard to breed certain animals in captivity. He didn’t get much past the thought that it is hard for man to completely re-create an animal’s habitat, and somewhere parts of the life cycle become lost. In all of my T. blondi keeping and breeding, there still remains a high failure rate of producing a good egg sac. This obviously seems counter-intuitive since invertebrates survive (avoid extinction) simply by producing large numbers of offspring very frequently. If invertebrates in the wild produced the same amount of offspring they do in captivity, these species would surely be extinct by now. So what is different? For all tarantulas, Darwin’s theory about captivity is definitely correct somehow. But for T. blondi, it is this theory plus a new idea: they are much more sensitive to environmental changes than other species. What do I mean by this? I have been able to mate Brachypelma smithi with ease. I have gotten good egg sacs consistently regardless of the environmental changes. I use to keep B. smithi in room temperature and whatever the humidity was in my house at the time. I have had success getting egg sacs any time of the year. I have since moved them into my “spider room” which is built and maintained for T. blondi. This room (not just the cages) is 75F and humidity is 80%. I still get good egg sacs from B. smithi. This is also the case for various Avicularia species and Psalmopoeus species as well.
But in the past few years, I have traded and sold off most of the species and now keep T. blondi, Xenesthis immanis, and Pamphobeteus spp. exclusively. I currently have over 30 T. blondi of various ages and sizes. Two of my adult females are quite old. One of my females (and the biggest) is at least 9 years old now. She currently is just a hair over 10.5” measuring from Leg I to Leg IV of the same side. As much as it pains me to admit it, I bought her as a juvenile over 8 years ago as a wild caught female. My second largest female is also a wild-caught, which I bought 6 years ago. (Note: I bought many wild caught T. blondi years ago, and I do not buy wild caught anymore, nor do I condone it—as it is cruel and they usually do not do well in captivity). Ever since these purchases, I stopped buying wild-caught tarantulas, as soon as I found out how they are collected from the wild. Getting back to the point, I have realized that the wild-caught T. blondi (when they survive in captivity), do get larger than those specimens that were reared in captivity. In particular, I noticed that the average carapace size of the wild-caught specimens is consistently larger than those of captive bred specimens of the same leg span. Here is another difference: on average, wild caught specimens are much more prone to hair kicking (and do it for the slightest disturbance), yet are much more responsive to mating.
Another factor that is in play here is diet. Many captive-bred T. blondi are fed crickets. The crickets that are sold in pet stores are commonly known as the European grey cricket. These insects are not found in South America. T. blondi in the wild will never see one. They eat rodents, snakes, native invertebrates, frogs, and the like. So perhaps the difference in their diet plays a factor in their metabolism, overall growth, and their ability to produce good offspring. We see the difference in human beings as well. As food and water quality has improved, so have our lives. “You are what you eat” definitely holds true.
So what is the “correct” way to take care of a T. blondi? The requirements in captivity are rather simple. First off, the cage for an adult should be at least 24w” x 12h” x 12d”. Substrate should be at least 5” deep to hold moisture. The substrate can be a mix of vermiculite, peat moss, coconut peat, and topsoil. It has to be pesticide free (duh) and be able to hold moisture to keep humidity relatively high. They require humidity levels of at least 70%, yet at the same time must allow fresh air in the tank. Stagnant air causes a moldy tank and can even lead to death. They will also need a large, shallow water dish with water in it at all times. They will also need a retreat to hide in. What I use is artificial retreats from Exo-Terra (large ones) and cut a bigger entrance hole for them. These hides also help keep humidity in its retreat. Decorations are optional, and if you must, I would recommend live plants to help increase humidity and oxygen levels.
As far as feeding is concerned, feed them well. These are animals that can get very big, so they need the food. I can’t begin to explain how many times I have received mature males or adult females that were tiny. The smallest mature male I have ever reared was 8” from leg I to leg IV of the same side. My females get at least this big, many get bigger. I feed mine adult mice, pinkie mice, hopper mice, assorted roaches, silkworms, crickets, snakes (every now and then) with an occasional frog. The quantity is up to the individual, but this species is a hobby favorite due to its size, so why not let them reach their potential?
When it comes to mating, T. blondi is relatively easy to get a good reaction. For those who own Citharischius crawshayi, you know the difficulty in keeping the male alive, let alone a good egg sac. For T. blondi though, it is easy mating. The problem is getting an egg sac that is viable. Throughout my span of keeping T. blondi, the males have always been able to achieve successful insertions. Yet, when it comes to egg sac production, it is a 50/50 chance, and then keeping the eggs with the mother for 30 days without getting eaten or discarded is even harder. First and foremost, T. blondi (I believe) is much easier to mate because the males, if fed properly, get as big as the females. The male has a much greater chance of being able to push her off than a C. crawshayi male. But when it comes to egg production, there is a high percentage of failure. Here is where I revert to Darwin’s thought about [some animals] having difficulty producing offspring in captivity. No one really knows the answer to this, we just know that if an egg sac is produced, your odds of getting a successful hatch is better if you pull the egg sac from the mother and incubate it yourself.
Upon getting a successful hatch, you can expect between 50 and 100 spiderlings each about ¾”-1” long. They appear to be almost a shiny bluish-black color around this size. And boy, will they eat. It is next to impossible to over feed a T. blondi spiderling. They will eat fruit flies, pinhead crickets and other insects of similar size. Humidity becomes extremely important at this stage, because T. blondi spiderlings are even more sensitive than the adults. What also needs to be taken into consideration is that as spiderlings they will molt very frequently, so they need moisture constantly. If fed properly, the female babies should reach 3” to 5” within a year. Males can get even bigger, as I have power-fed many to get on cycle with the females. Power-feeding a male can push him to mature in less than two years. The fastest I have achieved is a male spiderling reaching sexual maturity at 8” in 15 months. Babies should be separated (this goes with ALL species) to avoid cannibalism. How to house them is not important as long as the environmental conditions are met and they are all separated.
The T. blondi is a staple tarantula in any hobbyist’s collection. A tarantula that gets big enough to eat other tarantulas makes them much more fascinating. (Please note I do not condone tarantula cannibalism—I just wish my female C. crawshayi knew this!) As with all tarantulas, they are fascinating creatures and have definitely earned their place on earth. Though they are not as colorful as X. immanis, their sheer size more than makes up for their simple chocolate-brown coloration. Just remember, these giants need proper care, and hopefully within this essay will answer any questions about keeping them and understanding them have now been answered.