Tegu variants

[Andyroo]

Trusted Kindred,

I have a curiosity about tegu lizards:
I see all manner of variants and all manner of so-called sub-species and line-bred options online. Some suggest these variants/sub-species are valid (the colours certainly are), others say it's BS. These "Giant" Chacoan white-heads, for example: are they an actual sub-species and/or local variant that's actually bigger than the regular Arg.B&W, or is it a sales ploy?

I'm also curious about all of this line-breeding, as this makes me uneasy considering the 10++ year investment. Does it impact vigour? Durability? Brains?
Big @ white-head is good, but I also do quite like the reds... however, the breeder(s) dealing in what looks to be the nicest (Paraguayan?) goes on&on about his fabulous line-breeding programmes, so I don't/can't know if these are in that programme.

If I do pull-trigger, in theory I'd like to go with the fellow selling captive-hatched Florida invasive-wild Arg.B&W but for my interest is bigger-as-better, thus the giant white-head question. Ah, but those lovely reds...

Note: I'm not in any rush...

 

[Deadliestviper7]

I'd get two and compare them, get a white head and a Florida variant, I definitely see differences in tegus, some seem bigger, other varieties have different marking etc.

 

[Viridis]

This is going to be a long reply, so bear with me. It's also 1am so I may be kind of all over the place. I'll come back tomorrow and correct any mistakes.

Trusted Kindred,

I have a curiosity about tegu lizards:
I see all manner of variants and all manner of so-called sub-species and line-bred options online.

The only valid species/subspecies currently are:
Salvator rufescens (Red Tegu)
Salvator merianae merianae (Argentine B&W)
Salvator merianae buzioensis (See Below)
Salvator merianae sebastiani (See Below)
Salvator duseni (Yellow Tegu or El lagarto colorado del cerrado)
Tupinambis cryptus (Cryptic Yellow Tegu)
Tupinambis cuzcoensis
Tupinambis longilineus
Tupinambis matipu
Tupinambis palustris
Tupinambis teguixin (Common Golden Tegu, Black Tegu, Golden Tegu, Colombian Tegu, Yellow Tegu)
Tupinambis zuliensis

And then the rest of Teiidae, but I assume you're only referring to these 2 genera.

I'm not entirely sure S.m.buzioensis or S.m.sebastiani actually exist. There's a couple papers referencing them, but I'm not 100% sure they're accepted subspecies. There's very little info online about either.

The only species (to my knowledge) currently in the hobby are S. rufescens, S. merianae, and Tupinambis teguixin. Now, that said, T. cryptus is also found where T. teguixin is collected, so it's entirely possible T. cryptus is also in the hobby.

Some suggest these variants/sub-species are valid (the colours certainly are), others say it's BS. These "Giant" Chacoan white-heads, for example: are they an actual sub-species and/or local variant that's actually bigger than the regular Arg.B&W, or is it a sales ploy?

S. merianae is quite polymorphic as a species, much like Thamnophis sirtalis sirtalis, Corallus hortulanus, Correlophus ciliatus, numerous Dendrobatids, even humans. Tegus such as the "Chocoan"/"Extreme White", "blue", &c. are really just a marketing ploy. Kind of like crested geckos, where if an individual has trait 1, 2, 4, and 7, it's x "morph", but if it has 1, 2, 4, and 6 it's something else, regardless of what the parents were (I realise there is some success with certain blood lines breeding true, but that's not the majority). Here's an example of the variation within a population (odd but interesting article too). In captivity, the top one would be considered "different" enough to be called something else, when it's really just the genetic variation within a population, and a species. It's basically just people wanting "the next big thing" so they see things that aren't there, or omit important information in order to make $$$. I could go on, but it would turn into a rant haha.

The original "blues" were from a handful of animals (I forget exactly how many; 5? 6?) imported from Colombia, separated and subsequently named because it was "different enough". So at best, they are a specific locality of S. merianae. But as I said, if it looks sort of like a blue, people will call it a blue, even if it doesn't trace back to the original group.
So are they specific localities? sure it's possible, but nobody has that info, or is willing to share it. Is it possible they are a new species or subspecies? sure; but until somebody publishes a widely accepted peer-reviewed article proving it genetically, they are all Salvator merianae.

There are some legitimate "morphs" (in the way hobbyists use it) such as albino (which I would argue aren't actually albino, but amelanistic) or anerythristic. And of course the hybrids like "Purple", "All American"/"Merica", "Majestic", "Peach" and "Black Flame" (all S.merianae x S.rufescens).

I'm also curious about all of this line-breeding, as this makes me uneasy considering the 10++ year investment. Does it impact vigour? Durability? Brains?
Big @ white-head is good, but I also do quite like the reds... however, the breeder(s) dealing in what looks to be the nicest (Paraguayan?) goes on&on about his fabulous line-breeding programmes, so I don't/can't know if these are in that programme.

If I do pull-trigger, in theory I'd like to go with the fellow selling captive-hatched Florida invasive-wild Arg.B&W but for my interest is bigger-as-better, thus the giant white-head question. Ah, but those lovely reds...

Note: I'm not in any rush...

I want to preface this by saying I'm not a trained geneticist, I just read papers, so take the following as you want.

There can be problems with inbreeding (as is seen in guppies, dogs, humans, plants, &c.), and these should be taken into consideration when breeding. For example see this and this. Bloodred cornsnakes have unusually small hatchlings, male patternless leopard geckos are known for having low fertility; both believed to be because of intensive inbreeding. Hypothetically, you can breed out the "bad" traits (as people do with guppies) and end up with fairly healthy animals. Inbreeding doesn't always result in severely deformed animals; just look at all the Australian or New Caledonian reptiles in captivity that are the result of a tiny foundation group. Hell, some lab mice strains are hundreds of generations inbred.

the "Paraguayan" title is usually refering to Salvator rufescens; but it could also be refering to S. merianae or S. duseni now that I think about it.... Man I hate common names.

The Florida tegus are just feral S. merianae.

Why do you consider bigger better? Some animals are only bigger (usually weight wise) because they were power fed from birth and are simply overweight. Just like a lot of retics.

Alright, I'm tired. I'll add more tomorrow.

 

[Andyroo]

Viridis, you're a rockstar, thanks!
And with a bit of follow-up reading & reference- nice.

This initial query was based in part on us offering on a new house, somewhere with space for a bit of proper 'bucket-list'. That house went in Sept., but it has come back and we're offering again and on better footing. Applogies for my delay, particularly considering your investment in the response.

My interest in big would be primarily related to long rather than heavy - I'm all about fit critters with excessive space, filtration/flow, enrichment, flowers, varied diet etc. Admittedly Mondo the Jag.Cichlid overgrew is tank last year, but he's been promised some very stush new digs in the new place (a lap-pool & Chlorine gives me hives). No, my own waistline does not denote this attitude to husbandry...

I'm comfortably into my upper-40's, so I'll do the tegu that's been calling to my soul since kid-hood just this once. By the time he's in-house the price will be well into $4digits (enclosure, transport etc), so big just intends that I'm splurging on a larger something, then I might as well go all the way. If it costs me X% more for the largest morph (barring wife's input re. colour, IE: S.rufescens), the animal itself is still only a smaller part of the total price-tag. Of course this does assume that one morph may actually be larger, which your responses suggests is BS salesman's chat.

I've no intention of breeding, so no worries re. reduced fecundity, but I'm also not interested in risking congenital frailties. I'm also particularly interested in the Tegu's reputation for smarts... and our road-rescue mutt is well & certainly brighter than the high-dollar pedigree on the adjacent cushion.

Thanks again and best regards,