teguixin information and photos

[neotropicalherps]

Good morning,
I am interested in sorting out the species known as Tupinambis teguixin - sometimes called the golden tegu, sometimes called the black and white tegu. Has anyone bred these lizards? If so I would be very interesting in seeing photos of hatchlings and the parents. Does anyone have photos of these lizards taken in the wild with locality data? Again, I am interested in seeing the photos and discussing the habitat and behavior.

 

[SnakeCharmr728]

As far as I know, they have not been bred in captivity in the US before.

 

[neotropicalherps]

There are websites that claim to have captive bred teguixin. They are quite common, and in the pet trade so I would suspect multiple attempts to captive bred them. I would also be interested in knowing about failed attempts to captive bred them. In the above photo of museum specimens are two groups of teguixin, they are different species currently using the same name. I am interested in seeing what the hatchlings of each species look like. So, if you or someone else can help out that would be great.

 

[SnakeCharmr728]

I disagree, cb teguixin are not common in the pet trade. They do not breed as readily as the argentines, very small clutch size with incredibly long incubation times. If someone who is claiming to have cb ones but yet doesnt have copulation pics, egg pics and hatchling pics I don't believe it. I have heard it multiples times that they have not been bred in captivity in the US, but if someone has proof of otherwise please feel free to chime in.

Are you saying that the golds and the b/w's are two different species using the same name or is it just that they have color differences based on localities?

 

[neotropicalherps]

Yes, teguxin is in the pet trade (but it may not be common), but it is relative common in the field. In the wild females lay eggs in termite nests and they hatch when heavy rains soak the nests, thus they do, or may, have relatively long incubation periods that are flexible. Currently there are at least four species being called teguixin, I can identify them as different when looking at mature adults, but I can't yet identify hatchlings very well. The scale counts and scale arrangements overlap or are the same on most of the four species. Two of the species are separate geographically from the other two (I think), but two species are living side by side (based on gene sequences). One reason why they may not have been bred in captivity - at least not very often - is because there are different species, which would be unlikely to reproduce, or produce fertile offspring. There is also the problem of names - Tupinambis teguixin has been long confused with what is now Salvator merianae (formerly Tupinambis merianae) because they are both sometimes called the black & white tegu, but they quite different animals. If you look at the photo I posted most of the animals are males, the ones on the left have yellow chins with black spots, the ones on the right have black chins (the four males on the left of the photo) and more slender bodies which are mostly black (the ones on left have contrasting bands). These two species are living together at some localities in northern South America.

 

[Deac77]

How can you call them 2 different species if right now they are scientifically the same. I agree they are not the same but until proven I have to disagree they are different species.

 

[neotropicalherps]

Well if people don't study them then they would always stay the same and nothing would ever change. They are different species because that is how they evolved, people/science have just not previously recognized it. Once I publish on it they will be recognized species.

 

[neotropicalherps]

Above are photos of the two species. The bottom left could belong to either species, the photo came from the net. The others are mine. On the top left the two individuals are the same genetically, on the right the second photo from the top is genetically significantly different from the ones on the left. So, I am interested in seeing photos of live teguixin hatchlings with the idea that the patterns will, in some way, be distinct.

 

[laurarfl]

They are not being CB in the US. People who claim they are CB are usually referring to the fact they are ranched somewhere, either in N or S America. It is a marketing term to make a sale unless you have exceptional proof. there is a gentleman in Germany who has in fact bred a captive pair of adults. I have bred an adult captive pair, but did not follow through with the incubation of two separate clutches.

The only person whose information I consider valid regarding species identification is Roadkill. I have seen his published work on tegu studies and he is a credible member who has been on these forums for years.

 

[Roadkill]

While I've often felt there is definitely the possibility of Tupinambis teguixin and Salvator merianae being complexes and both comprised of several species, I'm also very cautious when people insist something is a new species because of slight colouration differences, particularly in organisms like tegus that show TREMENDOUS variability.

Let me share with you a story. I know a fellow who without doubt has struck me as being one of the most knowledgeable salamander taxonomists I've ever met. Particularly with the southeast asian salamanders, an area full of all kinds of species that are a slight difference from their nearest species relatives. I showed him a salamander from asia one time and he clearly identified it to a specific species and pointed out the geographic origin of it. A year later I showed him a salamander that he identified as a related species from a different area nearby. "But....it's the same salamander" I said. No, no, no, he insisted that although these two were similar, they were not the same species, some people have thought so but he was familiar with the research on them and was working on clearly delineating the species. "No, you fail to understand what I'm telling you", I said. "That is the same salamander - the exact same salamander as I showed you last year". It had aged, changed its colour pattern, put some weight on in certain areas. Surely I must have mixed it up with some other salamanders I had. Nope, no other salamanders from that region, definitely not even in the same tank: one salamander and only that salamander in the one tank. No mix up.

Some taxonomists are splitters, meaning they want to write a new species for every little difference they see. Works ok for entomologists. Not so well for vertebrates. When it comes to tegus, I really, really want to see the data before I will acknowledge that there are cryptic species. neotropicalherps, you say that you have tegus that are "genetically significantly different", by this what do you mean? I'm genetically significantly different from my sisters, I have a Y chromosome they do not. My sisters are also genetically significantly different from each other, some come from one mother, others from another. This doesn't make them different species. Are these significant differences commensurate with the geographic distance from each other and reflect a predictable gene flow? Greater than predicted? Less than predicted? Many people use statistics, seems to be that few understand them. Saying "genetically significantly different" doesn't say much of anything. What level of genetics are we talking about, what were the genetic traits you've used to make the estimation? What is your sample sizes for each group and what size area do your groups cover? Are you relying on solely museum vouchers or are you utilizing both historical and current data points?

Forgive me for sounding judgemental, but what you've presented so far is a little troubling. You claim there are at least 4 species and are looking to get the information to prove this. This isn't science, this smacks of agenda. Science definitely has hypotheses which it seeks to test, but it sounds like you've reached your conclusion and are now looking for the data to prop that conclusion up. Don't get me wrong, I welcome good science and stringent testing to demonstrate that there are more species in the tegus than what we've uncovered so far, I'm a firm believer they exist (they aren't the "blues" and "extremes", but they are likely out there). But like you've somewhat pointed out, people in the past have done some bad science and really muddled the water, so to speak. Presch represents a fine example of someone wanting to get published and clearly not paying enough attention to the details and thereby screwing up royally. I'm hoping you aren't about to commit the same. For example, while I agree with the endpoint of the Harvey, Ugueto & Gutberlet paper delineating Salvator and Teguixin (I'm sure Laura can attest to the fact that I've been yammering about the Southern vs. the Northern clades for years), their methodology was sloppy and incomplete and I do not agree or support their basis for the delineation: if that paper had been submitted to me for review, I would have told them that they needed to familiarize themselves with the species much better because their differentiation doesn't hold up.

 

[neotropicalherps]

Humans make mistakes, but science is self correcting. The "agenda" is a hypothesis that gets tested experimentally. Right now my hypothesis is that teguixin is at least four specie. The genes (12s, 16s) from two have already been sequenced. They are about 4% different and living side by side - humans and chimps are about 2% different. When a hypothesis is not supported by the evidence it is abandoned. A year or so a go, I though I had three species of cryptic parrot snakes,the DNA did not support it so I moved on. But in 2010 I realized the snake Brachyorrhos albus was many species - today it is three genera and nine species, with a few more than have not yet been described. You can download the papers at http://fieldmuseum.academia.edu/JohnCMurphy. You should not be so hard on Presch - yes he was wrong, but he was attempting to sort Tupinambis when the concept of polytypic species was in vogue (this concept was a disaster for a real understanding of biodiversity). The Harvey et al. split of Tupinambis and Salvator has recently been supported by a huge molecular study of squamates done by Pyron et al. (2013). You have to remember they are looking just at the molecules (with some limited morphology) because CITES has made these animals difficult for science to examine despite the fact they are hunted and consumed in the millions annually. Science is never done, a paper gets published and it is never the last word, there is always something else to do, and much of what gets published gets proven wrong at some level and replaced that is the way knowledge increases.

 

[Roadkill]

My apologies to you, neotropicalherps, I had assumed you were closer to the beginning of a project rather that closer to finishing it. I separate agenda and hypothesis as the hypothesis should be approached neutral, an open mind to wherever the data leads you. An agenda biases one to committing a type 1 error. Indeed, science is self correcting. As I try to say it, science doesn't write in stone, it writes in water. No need to belittle this point.

With the Harvey et al. split, like I said, I support the endpoint, and I wholeheartedly agree with the other works they used to support their conclusions. However, there is no denying that with particular attention to Tupinambis/Salvator, they have shown very shallow effort, used a deplorably small sample size for their own analysis, and focused on a historically stressed morphological trait to discern the two clades that is egregiously in error: the loreal scales. Sufficient experience with these species should have convinced them this wasn't the trait to put in their key.

While CITES has made it somewhat difficult, there's more at play than just this point. The actions of international scientists in many, many ways have resulted in them shooting themselves in their own feet. There is a well founded distrust of Americans in South America, and when it comes to biology, it has little to nothing to do with governmental politics, scientists themselves are first-hand responsible for fostering the mistrust.

Anyhow, having looked over your link, I see you have a focus on Trinidad and Tobago, and I have to admit I've always suspected these should be their own species. I'm pleased to see someone attempting to address the issue with both morphology and stringent genetics. I eagerly look forward to the outcome. Are you focusing on T. teguixin exclusively? I invite you to PM me, I would be seriously interested in continuing our discourse. I might be able to help you increase your data set.

 

[neotropicalherps]

Small samples are generally the rule in squamate studies because specimens tend to be difficult to come by. But, when studying something that is in trade there is no excuse for keeping ridiculous restrictions on moving extant museum specimens on loan across international borders. As a result I restrict my sampling to specimens in US museums or specimens I collect myself with permits. As for the divided loreal, it is actually a pretty good trait, it may not work 100% of the time, but few morphological traits are invariant. I have seen a few teguixin with divided or fragment loreals, but the traits in combination hold up relatively well to separate Tupinambis and Salvator. I am only working on teguixin because it is present on T&T. My long term goal is do do a comprehensive biogeographic analysis of the T&T herpetofauna. So, I am looking at everything, and revising my 1997 book.

 

[Roadkill]

You say you've seen a few T. teguixin with divided or fragmented loreals. I've seen quite a few Salvator sp. that possess only a single loreal, in fact I have a whole lineage of S.merianae with nothing but single loreals. Next we have the usage of dichotomous keys: who typically uses them, people highly familiar with the species in question and their variations, or people rather unfamiliar with them? The single loreal=Tupinambis, 2 loreals=Salvator doesn't hold true as often as it should (either direction), it does not make a great key point. When faced with a combination of traits, yes you are more likely to get a correct identification, but we both know the average person doesn't want "the list" , they want the quick inviolate fix, my stance is the loreal scales do not meet that criteria. At the very least that key should read Tupinambis typically have 1 loreal scale, Salvator typically has 2.

 

[neotropicalherps]

When you say you have a whole lineage I assume you mean a captive bred lineage, correct? So, an ancestor had the trait and you encouraged it by breeding the adults? On another topic, how much variation have you seen in the palpebral membrane (the clear membrane in the lower eye lid). Some have large window-like segments, others do not, the membrane is divided up into tiny segments. Have you seen this?

 

[Roadkill]

I would assume an ancestor had the single loreal, but it has nothing to do with me encouraging it. These were from a captive colony of research specimens, they were retired from research and surrendered to me instead of being terminated. Not a single double loreal in the lot (even though I know the original colony stock they came from indeed had double loreals - whether any of the parents of the ones I now possess did I cannot say), so I can't select when I have no selection.
To be honest, I haven't paid much attention at all to the the palpebral membrane. I guess it is something I will have to take note of.

 

[neotropicalherps]

In teguixin I have found very little morphology that actually differentiates them, supraoculars, supracillaries at the last supraocular, coloration/pattern. There are two different types of paplebrals but so far I have not been able to correlate them with other traits. The loreal is single in most specimens but a few have a small corner of it divided, or composed of several small scales. Its not divided in half by vertical seam as in Salvator.