Pyxicephalus Differences

[tgampper]

It seems that many people who keep African bullfrogs are having diffiulties telling the two species apart. First, the popular names are confusing. In Africa, Pyxicephalus adspursus , the "African Bullfrog (in U.S.)" is known as the Giant Bullfrog, while its smaller cousin, Pyxicephalus edulis is known as the African Bullfrog. The second problem is the assignment of new scientific names.

Subfamily: Pyxicephalinae
Genus: Pyxicephalus
* Species: Pyxicephalus adspersus Tschudi, 1838
**Synonym: Pyxicephalus adspersus adspersus Parry, 1982
*Species: Pyxicephalus edulis Peters, 1854
**Synonym: Pyxicephalus adspersus angusticeps Parry, 1982

Source: Frost, Darrel R. 2010. Amphibian Species of the World: an Online Reference. Version 5.4 (8 April, 2010). Electronic Database accessible at Amphibian Species of the World
American Museum of Natural History, New York, USA.

OK, time to eliminate the confusion.

Pyxicephalus adspersus

1. Upper jaw withour irregular vertical pale bars
2. No white spot on tympanum (ear drum)
3. No pale interorbital bar
4. Distance from eye to tympanum is about twice the diameter of the eye

Pyxicephalus edulis

1. Upper jaw with irregular pale bars
2. White spot on tympanum
3. Distance from eye to tympanum is about the same as the diameter of the eye

There is a third species, Pyxicephalus obbianus (Calabresi's Bullfrog) that I have not seen in the pet tade and is endemic to Somalia. At one time, the genus Pyxicephalus had about 12 species, most of the smaller species moving into the genus Tomopterna (or sand frogs, native to Africa and India).

I hope this helps

[John]

Thanks for posting this Terry. I think the story is a lot more complicated than this though. I've personally seen several frogs of Southern African origin that are neither Pyxicephalus adspersus nor Pyxicephalus edulis, but are certainly members of the same genus but have yet to be described by science. It's rather frustrating because these make it into the pet trade all the time.

[Amphibians]

Some pictures would definetely help, maybe a section of the caresheet could be dedicated to this? It is a shame that a majority of people posting here asking if they got a giant are told after the fact that its a dwarf.

[Tofuman]

At what age does a Dwarfs stomach start to turn orange?

[tgampper]

Thanks for posting this Terry. I think the story is a lot more complicated than this though. I've personally seen several frogs of Southern African origin that are neither Pyxicephalus adspersus nor Pyxicephalus edulis, but are certainly members of the same genus but have yet to be described by science. It's rather frustrating because these make it into the pet trade all the time.

Thanks, John! The world of amphibians is becoming more complicated as time goes by. Many species are shifting to new genera and if one does not keep up with the changes it can be very confusing.

I found a fourth species, Pyxicephalus cordofanus (nomen dubium), not much is known about it. Also, Fejervarya rufescens, this species looks very much like P.edulis.

Hildebrandtia ornata is a nice looking frog from southern Africa that is also known as Pyxicephalus ornatus.

Most of the species in Tomopterna look like smaller versions of their Pyxicephalus cousins. I wonder if these "sand frogs" are being confused as color morphs of P. edulis?

[John]

I suppose that is quite possible. We need to get some photographs so we can compare them with what's showing up in the pet trade.

[Kevin1]

WOW Thank you so much for posting this. We (pyxie enthusiasts) really needed a good explanation between the two major species.

[tgampper]

WOW Thank you so much for posting this. We (pyxie enthusiasts) really needed a good explanation between the two major species.

I agree

I've kept an African bullfrog in the past and enjoyed it being a part of my life for 20 years. It is so important that people do a little homework before buying frogs or toads so they can plan a suitable habitat for their pet. The genera Pyxicephalus and Tomopterna are in chaos as there are new species being discovered that have not yet been identified by scientists.

[Paul Rust]

How about creating a full blown article Terry? I know it takes a lot of time and effort but it would be a superb piece if you wrote it!

[tgampper]

I have prepared an African Bullfrog Identification Guide. This will hopefully explain the differences between Pyxicephalus adspursus and P. edulis. Also covers some species in the genus Tomopterna, popularly known as sand frogs or "pyxies". Please click on the link below to access the document. I will be looking forward to your comments and suggestions. Thanks!

http://xenopus.freeshell.org/abig.doc

[onedge30]

Thank you very much, Terry! That is great to begin to see why the confusion exists. And if a seller does not have an interest in pixies, I can see how the confusion can easily pass by their inspection.

Yes, an article would be fantastic. We could even include it with a specific guide on sexing them as well. Pictures of the contrasting differences would really help. I am highly visual and love the visual reference.

Wow, if only studying a species in the field would actually pay something. Very sad that to get the information, someone must give up everything to dive completely into the study.

Question, Terry. Where does this funny 'species'(used very loosely) coming from Tanzania fit? It really looks like edulis.

[tgampper]

Thank you very much, Terry! That is great to begin to see why the confusion exists. And if a seller does not have an interest in pixies, I can see how the confusion can easily pass by their inspection.

Thanks for the comment, Jeff! I am sure that a few breeders/importers sell frogs without knowing what species they are. A local pet shop was selling a beautiful toad but didn't know what species it was, I was the one who did some research and identified it. Why should the buyer have to do the "dirty work"?

Yes, an article would be fantastic. We could even include it with a specific guide on sexing them as well. Pictures of the contrasting differences would really help. I am highly visual and love the visual reference.

I am not sure how to put the article on the forum, that is why I provided a link to my website. Maybe John or Kurt would be able to figure it out. I am also highly visual and love lots of pictures. John is the "pyxie guru" and could help out with the sexing issue. My main interest is in Pipidae and amphibian taxonomy.

Wow, if only studying a species in the field would actually pay something. Very sad that to get the information, someone must give up everything to dive completely into the study.

That would be so cool to do some real field research. The zoo I worked at has a close relationship with the Jo-burg Zoo and the South African Amphibian Conservation Center. I had an opportunity to work with Mantellas, Madagascar rain frogs, African reed frogs and several critically endangered/extinct in the wild amphibians. It was a great experience!

Question, Terry. Where does this funny 'species'(used very loosely) coming from Tanzania fit? It really looks like edulis.

You have to remember that the family Pyxicephalidae has some 67 species and to make it more confusing is that species are being assigned into mew genera. As DNA analysis improves, biologists are finding out that species they thought were related are in reality not related at all. That's one reason why Pyxicephalus was split into at least two genera. Some scientists consider adspersus and edulis to be subspecies. There is a third species, P. obbianus that is endemic to Somalia which I don't know much about right now. I understand that there are Pyxie hybrids around. Maybe that's your "funny species"!

[onedge30]

Arrgh! I think my brain is going to explode!

Ok, just looking around FF at pictures, I find what was thought to beobbianus and serveral that look like adspersus but with edulis coloring!!

I love all the information, but trying to look at the visuals with out a specific 'true' guide, your mind just begins to smoke.

I wonder with all the pictures and comments on FF, if we could begin to build a pic genius library with pictures from FF? And maybe some from crossover sites. If we could put together a verbal description for each species to start with.

Oh, just thinking out loud.

Cheers

[Jace]

I never realized the diversity within this group! I stumbled onto this species quite by accident-my first male was brought into the petstore a cute quarter-size froglet and not even the people selling him realized what he could grow into. It was a bit of a surprise to realize that my so-called "pyxie" was going to remain anything but!! Now my total is up to three P. adspersus and I have been searching in vain for a P. edulis to add to my collection with no luck.

I agree completely with Jeff-any sort of written and visual aide would be amazing. Thanks Terry!

[Kevin1]

Thanks a lot Terry This will help us all a great deal.


As for the "tanzanian subspecies" I'm thinking someone must have been very confused(me!). I was told about it when I first really started to research pyxies. So I started searching for information on it. Needless to say I didn't find much..For awhile I thought it might be P.Adspersus Angusticeps...Now I think the people that told me about this "Tanzanian subspecies" were just as confused as I. lol

[tgampper]

Thank you all for the kind comments. I used to keep P. adspersus a few years back and since moved on to other species. However, all the commotion going on among African bullfrog keepers has got me interested again. The guide is only a beginning. As I collect more information about this group, I will update the article. I would appreciate any assistance you can give me. Thanks

[tgampper]

Thanks a lot Terry This will help us all a great deal.


As for the "tanzanian subspecies" I'm thinking someone must have been very confused(me!). I was told about it when I first really started to research pyxies. So I started searching for information on it. Needless to say I didn't find much..For awhile I thought it might be P.Adspersus Angusticeps...Now I think the people that told me about this "Tanzanian subspecies" were just as confused as I. lol

Hi Kevin,

Ahhh, the famous P. adspersus angusticeps It seems that in 1982, some scientist named C. R. Parry decided to revise the genus Pyxicephalus. See if this is confusing:

Pyxicephalus adspersus edulis (Parry, 1982)
Pyxicephalus adspersus angusticeps (Parry, 1982)
Pyxicephalus adspersus (Parry, 1982)

So is P. edulis a subspecies or a distinct species or even the same species as P. adspersus?

Alan Channing (1994) says that P. edulis differs by its call, behavior, smaller size, shorter dorsal ridges and smoother skin. Lambiris (1989) considers P. edulis a subspecies and points out the following distinctive features: white spot on tympanum, bars on the upper lip and interorbital stripe (as mentioned in my article).

[onedge30]

Kevin,

Yea, that whole renaming with the adspersus in each name is crazy. I think in my research found that that is now considered obsolete and not listed in the current taxonomy. I think that was Red List.

[Kevin1]

Hi Kevin,

Ahhh, the famous P. adspersus angusticeps It seems that in 1982, some scientist named C. R. Parry decided to revise the genus Pyxicephalus. See if this is confusing:

Pyxicephalus adspersus edulis (Parry, 1982)
Pyxicephalus adspersus angusticeps (Parry, 1982)
Pyxicephalus adspersus (Parry, 1982)

So is P. edulis a subspecies or a distinct species or even the same species as P. adspersus?

Alan Channing (1994) says that P. edulis differs by its call, behavior, smaller size, shorter dorsal ridges and smoother skin. Lambiris (1989) considers P. edulis a subspecies and points out the following distinctive features: white spot on tympanum, bars on the upper lip and interorbital stripe (as mentioned in my article).

Ah..So according to Parry, P. A. Angusticeps was distinct from P. A. Edulis?.. I find that interesting.
I know that name is obsolete now..but do you know of any information that distinguished Angusticeps from the others?(adspersus, edulis, etc)

I appreciate all the information you have shared with us thus far, Terry.

Thank you all for the kind comments. I used to keep P. adspersus a few years back and since moved on to other species. However, all the commotion going on among African bullfrog keepers has got me interested again. The guide is only a beginning. As I collect more information about this group, I will update the article. I would appreciate any assistance you can give me. Thanks

Let me know if there's anything I can do to assist you. I'd be happy to help.

[tgampper]

Hi Kevin/Jeff:

Yeah, it's really confusing since much of the literature is obsolete. I think the confusion lies with the three distinct trends of thought concerning the genus Pyxicephalus. One side says that there is only two species in the genus: P. adspursus and P. obbianus; leaving P. edulis just another form of P. adspursus. Second, that P. adspursus and P. edulis are subspecies; and the third that there are three distinct species. I am going to side with Channing, Carruthers and Roedel and say that there are three species.

BTW, Pyxicephalus adspersus edulis (Parry, 1982) and Pyxicephalus adspersus angusticeps (Parry, 1982) are synonyms of P. edulus. My head is spinning