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rothschild.kevin

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I recently got a young Python and was told it was a stimsons but it looks more like a spotted to me what do u think?
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Can anyone explain how to actually tell them apart? I have a spotted that looks suspiciously similar to my stimmies....
 
It can be fairly subjective, however the dichotomous key from Cogger (2014) has:

3.
Dorsal pattern of ragged-edged, dark blotches which tend to coalesce on the anterior and posterior parts of the body; pale stripe along lower part of neck obscure or absent.....maculosus
Dorsal pattern of smooth-edged blotches, and/or bars and/or irregular cross-bands; pale stripe along lower part of neck usually well developed.....stimsoni


Mike
 
Thanks Mike, I had seen this description, it's pretty wordy and takes a bit of deciphering, just wondering if there were any other things people might have noticed or found to separate the species. It's so hard when their the size of a pencil. My little girl is coming into shed now, so when she's all fresh I might pop a pic up for opinions too.
 
Wordy as they may seem, these are the useable differences. Scale counts overlap so much that it is hardly worth the effort.

It might help to consider each feature separately. In decreasing order of usefulness, the distinguishing features are...

  1. Pale stripe on side of neck
  2. Edges of blotches
  3. Orientation of blotches

1. Stimsons have a clear and sustained pale stripe on each side of the neck. This stripe runs back from the head, slightly above the mid-line of the side. In Spotteds there may sometimes be present a semblance of a pale anterior stripe, however it will only be short, indistinct and/or non-continuous and located lower down on the side.

2. The edges of the blotches on a Stimson?s are fairly regular ? usually smooth. The edges of the blotches on a Spotted often have marked irregularities, such as spikes sticking out from them.

3. Blotches on backs of these pythons often tend to link together. Sometimes that link can be just a small narrow strip between them. At other times they completely coalesce to form a short band. In Stimsons, the blotches tend to link up across the snake and can often form a series of bands along the middle of the back. In Spotteds the bands to link together along the body and most linking occurs towards the two ends of the body rather than in the middle. Bear in mind that this feature is variable and not always reliable on its own. However, it is pretty safe to assume that if there is clear banding along the back, it is a Stimson?s rather than a Spotted.

With using any field identification characteristics, you need to familiarise yourself through experience in order to become competent at making accurate IDs. I?d suggest starting with images of each species using the AROD on-line database. Then using feature at a time, go through the two sets of images to see how the two species differ in that features. This will also give you a feel for how much that particular feature can vary in each species.

Once you are feeling more competent, then you can try googling images of each species. However, be aware that Google does only put up images of the species requested. I suspect that they search use photo captions first and then go to where the name occurs in print and post the nearest image to that. Even the name occurring in a caption is not a 100% guarantee that the given photo is of that species. You should find that after a while you can begin picking out the Spotteds in the Stimson?s pics and vice versa.

While I realise this is not exactly what you were after, hopefully you may find it of some help.

Blue
 
Thanks blue. Our spotted has a very prominent stripe, which was the first thing that made me question it. She's rather blue pre shed and with a slightly redder background colour. I'll have a better look once she is a cleanskin. Cheer.
Amy
 
I imagine you could find intergrades where their home ranges overlap or join.
 
Can anyone explain how to actually tell them apart? I have a spotted that looks suspiciously similar to my stimmies....

Hi Amy & Kevin.

Despite Blue's well intended post summarising well known authors descriptions of the two species and Mike's quote of Hal Cogger's dichotomous code; it's pretty much impossible to confirm exactly what you have. I can't open your attachment Amy but what I can tell you Kevin is that you appear to have a very nice little snake of the Antaresia group.

I know others will no doubt have a different train of thought (especially taxonomists...lol) but going on my many years of experience with Australian reptiles I'll offer the following opinion.

In all reality, when it comes down to all things being considered on the evidence available, just like the Morelia spilota group (Carpets if you like) it appears to me that there is strong argument to suggest A. maculosa (Spotted Python) and A. stimsoni (Stimson's Python) are not valid species, just all the same snake with the only real difference being slight variations in colouration and patterns.

I'll add that mid body scalation of 35 or less and size not exceeding 60cm are both valid evidence to recognise A. perthensis as a separate species.

I believe it can be argued, that just like A. childreni, the colours and patterns of the two recognised species mentioned above are a result of natural selection developed as a survival technique to suit the many and varied environments they inhabit and is not enough evidence to quantify them as separate species .

The only thing that differs is the morphological dorsal colours and patterns. It is my understanding that the size, scalation, cranial, dental and hemi penis descriptions are identical to A.childreni. There are no geographical barriers to inhibit co-habitation in the locations where each species distribution overlaps. All these currently recognized species can copulate within the group and produce fertile offspring.

I'll further add that the method to identify new species was at the time (1973 for A maculosa and 1985 for A stimsoni) based on very minimal requirements, thus allowing it to be very easy for new species to be proposed and accepted. (To tell the truth with the amount of re-classification of Australian herps at Genus level and the elevation of others to species level these days, I don't think it has changed very much...lol).

Cheers,

George
 
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Thanks for your feedback George, depending where you look, Antaresia ID can sound very subjective and largely based on trusting the breeder or seller to have their ID's correct. But seeing as how currently there are separate classifications (even though the scalation counts for the spotted are within the stimson range) it would be good to have it clarified in a usable means. Perhaps the taxonomists should consider maculosa as a subscecies of stimsoni or similar, maybe even locale, lol

Anyway, i'll try the pics on my PC instead of phone, see if that works
View attachment 314732View attachment 314733View attachment 314734View attachment 314735View attachment 314736
 
I imagine you could find intergrades where their home ranges overlap or join.

or in the pet trade considering they were all one species on Victorian licenses for years.

The only thing I have to add is that Stimmies do not seem to bite me while the other two do. I hate those spotted slugs as much as they hate me.
 
The only thing that differs is the morphological dorsal colours and patterns. It is my understanding that the size, scalation, cranial, dental and hemi penis descriptions are identical to A.childreni. There are no geographical barriers to inhibit co-habitation in the locations where each species distribution overlaps. All these currently recognized species can copulate within the group and produce fertile offspring.
Differences in genetic makeup define species, not differences in morphology. For example, different breeds of dog show extreme variation in morphology yet they are all one species. You also get different species that are morphologically indistinguishable, such as our ?rocky river frogs? (Litoria lesueuri, L. jungguy and L. wilcoxi) and marsh frogs (Limnodynastes fletcheri and L. tasmaniensis). In describing and identifying species, morphology is used as a tool and it is only useful to the extent that it reflects underlying genetic differences.

The ability to ?produce fertile offspring? is not a proof that both parents belong to the same species. While it is an essential attribute of all species groups, it is not exclusive. Examples of inter-specific breeding producing fertile progeny have long been recognised (particularly in plants where it is almost the rule rather than the exception).

Is there any particular reason you make no mention of the molecular data that has been collected from the three Antaresia populations in question? Perhaps the fact that it supports the division into three species?

I'll further add that the method to identify new species was at the time (1973 for A maculosa and 1985 for A stimsoni) based on very minimal requirements, thus allowing it to be very easy for new species to be proposed and accepted. (To tell the truth with the amount of re-classification of Australian herps at Genus level and the elevation of others to species level these days, I don't think it has changed very much...lol).
Advances in technology have allowed taxonomists direct access to the genetic makeup of organisms, instead of being solely dependent on visible features as an indicator of the underlying genetics. DNA sequencing, analysis of allozyme loci, the use of mitochondrial DNA and other techniques (such as cladistic analyses) have allowed direct insight into genetic and evolutionary relationships that previously could only be guessed at. As technology continues to improve our understanding of true the relationships between organisms will continue to crystallise and our classification of organisms will continue to be adjusted accordingly.

I know others will no doubt have a different train of thought (especially taxonomists...lol) but going on my many years of experience with Australian reptiles I'll offer the following opinion.
I would suggest that there are many respected taxonomists that have considerably more background in this specific area than even your ?many years of experience with Australian reptiles? provides. To be so dismissive of the likes of Laurie Smith, Dave and Tracey Barker and a dozen or more others, is not reasonable. They have the experience, the background, have put in the long hours researching and analysing, examining scores of specimens from across the full geographic ranges of each population. Yet you give them zero credence...
 
Blue, I had wondered about the genetic differences of the species assuming they are know and if it would be an accessible option to have a python properly identified this way. I would assume zoos and the like would have access but I'd think it'd be pricey for the regular keeper.
 
[MENTION=41261]Smurf[/MENTION]. Unfortunately I have no real idea. While I personally know a couple of people who have been involved in collection and use of molecular data, they are employed at the museum or a university. As these institutions have access to their own facilities and technical staff, as part their total infrastructure the actual cost of this is undetermined. Given the process it is high tech and labour intensive, I would imagine it would not be cheap to have done commercially... but I am only guessing. Sorry I can?t really help there.

How certain are you of it being a pure species?

While many people assume that natural hybrids exist amongst Antaresia, I have yet to hear about or read anything on a verified example. Nor have I come across any suggestions of clinal gradation from one species to the other. This would indicate that effective barriers to cross breeding do exist in nature. Barriers to inter-breeding do not have to be only physical, such as geographic separation or non-matching hemipene structure. They can also be behavioural and/or chemical. With the latter, sometimes mistakes can happen. For example, a female crossing a pheromone trail of a similar species while a male of that other species is following it. These sorts of accidents being rare, the gene flow between such cohabiting populations is still restricted to the point where speciation is maintained. It is therefore probably fair to assume that, without concrete evidence to the contrary and regardless of visual similarities between sympatric species, wild-caught specimens from an area where two species occur together are still likely to be pure species.

In captivity, however, misidentification of species has lead to unintentional cross-breeding and passing off of hybrid offspring as pure species. This has definitely muddied the waters with respect to a percentage of captive bred animals.
 
You have an absolute wealth of knowledge Blue! I'm still relatively new and have a lot to lear, so I'm glad there are people like you out there happy to spread the information.
I personally have no certainty about the purity of species of this little girl, I can only go from what I was told by the seller.
Since she has shed I should do a scale count for curiosities, just need to find where my partner stashed it :)
 
Smurf, like you I am still learning. I consider learning and the desire to learn as very important and so am happy to help if I can. This is also why I take the time (and space lol) to try and explain things where possible, as I believe understanding facilitates learning and also helps a lot with recall. I can say that I have made note of the thoughtfulness and positive attitude you have displayed through your own posts, both in this and other threads. That just makes it all the more worthwhile from my point of view. So good on you!

Probably the most fruitful thing you could do at this point is to post a couple of clear pics of your girl. A full body shot from above and a side view of the front end would suffice. That way those with an experienced eye could give their opinions. It should at least provide you with a clearer idea of its genetic leanings.

Just in case you are not aware, scale count ranges can be obtained from the Australian Reptile On-line Database (arod.com.au) under the ?Description? tab for each species ? it opens automatically in the ?Distribution? tab.

Blue
 
Thanks Blue, really appreciate your comments. I know I'm newer than a lot of people on here but I'm like a sponge learning what I can and sharing what I've learnt or experienced where it might help.
I tried some pics the other day but clearly my phone wasn't having a bar of it. Give it another go...
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Hopefully they work this time. It's hard to get a good side view because she's so interested in my phone

- - - Updated - - -

Ps, and yes thank you, I have read the scale count information in a couple of places I think.
 
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