Reptile & Amphibian Forums

Hello friends,
I was curious about hybridization between
different species of HLs. I read once that the CHL
sometimes crosses with the DHL, and because of that
I was wondering if it would be safe to house a Round-tail with a Desert, or would they mate and produce "mutt" offspring?
If so, what species are known to Hybridize? and will a male choose to hybridize if he has a female of his species, and a female of another housed with him. I guess that leads to another question. Are males of different species territorial
to one another? Thanks a lot!

Yours,
Phil

Hello Phil.

Hybridization does take place in the wild between CHLs and DHLs where there are contact points between species. DHLs and FTHLs may also hybridize, but the offspring are very possibly serile. The same is true for CHLs and DHLs. I monitored two interbreed zones for CHLs and DHLs several years back and found several representatives of the interbreeding. The male hybrids had, or should I say lacked, prominent hemipenes. The breeding postures and courtship behaviors are also different for CHLs and DHLs.

The hybridization is a chance encounter because of the different ecologocal and biological requirements of the different species, i.e. temperature of optimal activity, habitat requirements, and other factors.

Lester G. Milroy III

Those are some interesting notes Lester.
Do you know if there are any hybrids that will reproduce, either with hybrids or with pure strains from their parental mix?
Cheers!
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2 Kings 6:15-17

Unknown.

Hybridization in the wild has been probably going on for a long time. If it were successful, and a consistant occurance, we would find many hybrids in the field. Bottom line, we do not. So success is questionable. There may be morphological similarities in a possible hybrid, but DNA analysis would be the only to confirm its true status.

Lester G. Milroy III

Thanks Lester,
It's all pretty fascinating. I have kept African Cichlids (fish) for quite some time now. It's my understanding that the lake they come from has been fragmented and rejoined countless times throughout history due to fluctuating water levels and it has produced in this lake a multitude of variations on the chichlids that live there. They are continuously finding new color morphs and other variations. HL's must share some of that pattern over their history on this planet to produce the various species we have today.
It all makes me wonder how small the gene pool can get and still produce a healthy population of a given species. I know that there are folks out there that in-breed a given species of reptile for color variation. I also know that it can cause problems with health though.
Anyways, thanks again.
Cheers!
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2 Kings 6:15-17

Territoriality is not a behavior observed in any of the HL species. None of the US species establish territories that are defended. Two research biologists I know who work with the Mexican species also note no territorial behaviors over years of study.

It is not wise to mix species in small enclosures. One species may be more timid than another, as in Roundtails and Desert HLs. Also,the chances of parasite and/or bacterial transfer that one species has an immunity to may not be shared by the other species (unpublished data screen, Goldberg (personal communication)).

Lester G. Milroy III

Hybrids of coronatum X cornutum, platyrhinos X coronatum, mcalli X platyrhinos, platyrhinos X modestum, and orbiculare X hernandesi have all been noted. At least some of the offspring have been found to be fertile. Baur notes a coronatum X cornutum hybrid mated with a coronatum that produced eggs that hatched. Photos are available in his article.

Baur, Bertrand. 1984. Krötenechsen-Bastarde (Phrynosoma). Salamandra (1).

I am very aware of Bertrand's results in captivity. We discussed this several years ago. Coronatum x cornutum is what would be called an "unnatural hybrid" because there are no naturally occuring boundry overlaps for the species. The same with modestum x platyrhinos. In captivity, the controlled environment makes it possible, but what are the generational end results?

The orbiculare x hernandesi (douglasi) would be a possible natural hybrid, as would mcalli x platyrhinos.

Lester G. Milroy III

Hybrids can be a very distinguishing feature in clad identifiers (hernandesi can't produce young with cornutum for instance). Being that coronatum and cornutum can reproduce and produce fertile offspring they are not distinct species. They should be considered subspecies in the true definition. Due to changing land structures they have become separated but not enough to constrict reproduction. In my hypothesis I believe many HL species are very closely related and can produce fertile offspring. Fertile hybrids may be possible in bracconieri X taurus and cornutum X asio because in my observation they seem very closely related. If two species can reproduce but produce sterile offspring they are in the same clad but different species. If they reproduce and produce fertile offspring they are the same species. If they can't reproduce at all they are of different clads. What do you think?

Great thoughts Jeff.
I don't have much to add but questions on this topic.

It would seem to me if you have a bybrid that can reproduce it would seem quite possible to be able to stablize that hybrid. Would it simply be a sub-species then?

Would it be possible to hybridize a species that would be more able to withstand some of the habitat changes taking place for some species?

Cheers!
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2 Kings 6:15-17

Hey M.
I would think geographic variation should not be a defining factor at the species level. Many populations of hernandesi are isolated throughout the mountains of AZ. Should someone go through and label each population as a distinct species? A population of hernandesi in Alberta Canada and a population in Sonora Mexico go through drastically different weather patterns. Should they be distinct species? The definition of a species defines it clear- a group of organisms that can successfully reproduce with one another. If the definition were followed their would be about 6 species of HL and 13 subspecies (geographical variation is at the subspecies level). If people wanted to further separate subspecies by color or horn structure (I have seen drastically different color and horn structures in one population of platyrhinos) they could be pattern classes. I think it would be very interesting to publish a paper on the rearrangement of phrynosoma based on these definitions. Many scientist are quick to define species and draw lines so to speak probably because they wanted credit for describing a new species.

Most HLs prefer the same temps(all in the 90s) and they are able to seek this out by daily and seasonally adjusting their activity. I could keep solare outdoors all year here even though it is not native here. Most HL species are seperated because of past landform and elevation changes. You will notice captive HLs are active all day because they are in their preferred range. I hope this helps.

I have done a little searching and reading on the definition of species and find that there seems to be little agreement exactly what it means or whether it is really quantifiable in a solid sense.
One concept I find interesting in relating the the horned lizards is the concept of ring species. I'd like to see how that might play out.

Here are some interesting links I found on species definition:

http://evolution.berkeley.edu/evosite/evo101/VADefiningspecies.shtml

http://www.pbs.org/wgbh/evolution/library/05/2/l_052_02.html

http://www.revelationwebsite.co.uk/index1/menton/b4.htm

http://www.palaeos.com/systematics/Linnean/Species.htm
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2 Kings 6:15-17