Pyxicephalus Differences

[John]

This bears out what I suspected, and that is that we rarely see edulis for sale. Therefore, what are we seeing for sale really?

And related to this, is this frog Pyxicephalus edulis? The photo is from my African Bullfrog article:


It seems likely to me that it is.

[tgampper]

Jeff,

Do we have permission to use her photo on post #45? If so, that would be perfect.

John,

The photo you just posted is P. edulis. I was confused at first with the coloration and markings and thought it would fit perfectly in the genus Tomopterna, but the spot in the tympanum identified it as P. edulis. Also, the other features like the bars on the upper jaw, the distance between the eye and the tympanum and also the faint interorbital or interocular bar. We could use that photo also.

I would say that the individuals in both pictures are females, am I right?

[John]

I would say that the individuals in both pictures are females, am I right?

That animal is from the San Antonio Zoo. They acquired several individuals about 2 years ago now that were given to them as P. adspersus and they were puzzled as to why they weren't growing bigger, since they already have an adspersus male on display.

The animal in my photo is a male, in my opinion - I had 2 others with which to compare him, and they seemed female. The size difference between the sexes was not as pronounced as P. adspersus, but the shape dimorphism was similar to P. adspersus. I may have more photos of this frog. I'll see what I can find when I get a shot at my other computer.

[Malachi]

Its also kinda Odd that the edulis in the book has a body more similar to say american bulfrog.. where my edulis is fat bodied like the giants.

possibly its starved

[tgampper]

Its also kinda Odd that the edulis in the book has a body more similar to say american bulfrog.. where my edulis is fat bodied like the giants.

possibly its starved

Most of the pix I've seen of edulis look more like bullfrogs then the fat-bodied adspersus. Maybe it was the fine cuisine you been feeding them.

[tgampper]

This bears out what I suspected, and that is that we rarely see edulis for sale. Therefore, what are we seeing for sale really?

IMHO, I think many importers/sellers of frogs and toads are just taking the word of their supplier and not really finding out for themselves what species they do have. Popular names seem to be a problem. If you notice the excerpts from the book that Darryn supplied a few posts earlier - Carruthers list P. edulis as African Bullfrog. In most other places, the African Bullfrog is P. adspersus. So when some suppliers list P. edulis as African Bullfrog, technically they are not wrong. We as buyers need to be more aware. That's why I thought putting together a Pyxie guide would be most helpful.

Also, many frogs and toads have been assigned new genera or even families. This no doubt leads to confusion. I noticed that some ads list frogs using old names or synonyms, for the example we had earlier, Pyxicephalus delandi, actually in reality it's Pyxicephalus delalandei, now Tomopterna cryptotis. Sand frogs in the genus Tomopterna are also known as "pyxies".

I think we are probably getting more P. edulis but being sold as P. adspersus (which may not be misleading either, since some scientists do not make the distinction between edulis and adspersus). In fact, I kinda like edulis, they are smaller and more colorful. (Please excuse my ramblings )

[onedge30]

Until I see differently, I have to agree that the two images of edulis in #45 and John's unknown are the 'true edulis'. And what has been labeled as edulis, in the pet trade, needs to be identified.

Terry, I have the credit info for the image in #45, but I will double check on usage.

Another question comes up, for me, and that is that the images in #45 and John's, for edulis, are juveniles and not adults. So, what does a full adult look like?

I just receive an email from Louis du Preez with the pages from his book, A Complete Guide to the Frogs of Southern Africa. First, shock as to my requests for help on clarification had reached him. Second that he took the time to send information. What I am getting at ..... I sent him back images of what we seen labeled as edulis and an image, that I believe, to be an adult African Bullfrog - edulis. So, I hope to hear from him, and get some clarification.

This is the image that I believe may be an adult African Bullfrog - edulis. We will see.

[tgampper]

Until I see differently, I have to agree that the two images of edulis in #45 and John's unknown are the 'true edulis'. And what has been labeled as edulis, in the pet trade, needs to be identified.

I agree with you. I think Malachi brought up the fact that edulis are more "bullfrog" shape than adspersus. That might be another clue in helping describe the species.

Terry, I have the credit info for the image in #45, but I will double check on usage.

That would be awesome! Thanks!

Another question comes up, for me, and that is that the images in #45 and John's, for edulis, are juveniles and not adults. So, what does a full adult look like?

Well, I think they are adults. There are very close similarities between juvenile edulis and adspersus. du Preez and Carruthers, in the book you mentioned, states that juveniles of both species are "distinctively marked bright green and black with a pale vertebral line from snout to vent." The photos in the book show that the vertebral line is a pale greenish color and that edulis has a white spot in the tympanum.

I just receive an email from Louis du Preez with the pages from his book, A Complete Guide to the Frogs of Southern Africa. First, shock as to my requests for help on clarification had reached him. Second that he took the time to send information. What I am getting at ..... I sent him back images of what we seen labeled as edulis and an image, that I believe, to be an adult African Bullfrog - edulis. So, I hope to hear from him, and get some clarification.

That is awesome. Dr. du Preez is professor of zoology at North-West University and heads the African Amphibian Conservation Group
http://www.puk.ac.za/fakulteite/natuur/soo/drk/aacrg/index.html

I hope he gets back with you soon.

[tgampper]

Until I see differently, I have to agree that the two images of edulis in #45 and John's unknown are the 'true edulis'. And what has been labeled as edulis, in the pet trade, needs to be identified.

I agree with you. I think Malachi brought up the fact that edulis are more "bullfrog" shape than adspersus. That might be another clue in helping describe the species.

Terry, I have the credit info for the image in #45, but I will double check on usage.

That would be awesome! Thanks!

Another question comes up, for me, and that is that the images in #45 and John's, for edulis, are juveniles and not adults. So, what does a full adult look like?

Well, I think they are adults. There are very close similarities between juvenile edulis and adspersus. du Preez and Carruthers, in the book you mentioned, states that juveniles of both species are "distinctively marked bright green and black with a pale vertebral line from snout to vent." The photos in the book show that the vertebral line is a pale greenish color and that edulis has a white spot in the tympanum.

I just receive an email from Louis du Preez with the pages from his book, A Complete Guide to the Frogs of Southern Africa. First, shock as to my requests for help on clarification had reached him. Second that he took the time to send information. What I am getting at ..... I sent him back images of what we seen labeled as edulis and an image, that I believe, to be an adult African Bullfrog - edulis. So, I hope to hear from him, and get some clarification.

That is awesome. Dr. du Preez is professor of zoology at North-West University and heads the African Amphibian Conservation Group.

I hope he gets back with you soon.

[tgampper]

Here is the link to the African Amphibian Conservation Research Group:

AACRG

[Malachi]

Perhaps mine isn't the "true" Edulis because he is defiantly round bodied like the pictures ive seen.
His legs are pretty small too, the Edulis in the book picture has American Bullfrogish legs

[onedge30]

Ok, my head hurts. And I am most likely too dense to understand all this, so help me out. These are the emails from a conversation. I will try to post all the links that match.


Dear Jeff,
You are correct - identification and species boundaries in Pyxicephalus are confused and are currently subject to research by several groups (although in general the biology of this group is well studied). There is no question that P. adspersus and P. edulis are different species, however, immatures and smaller individuals can be very difficult to identify. Also, it is likely that multiple species are hiding under each of these names, occurring in different parts of Africa, contributing geographic variation to the difficulties of identification. In general, in southern Africa, P. edulis occurs in the lower lying coastal and river valley savanna, with P. adspersus in the high-lying (>1000m asl) grasslands, inland savanna and semi-arid areas.

I suggest that you find a copy of:

DuPreez L & Carruthers V (2009) A complete guide to the frogs of Southern Africa. Struik-random House, Cape Town ISBN: 978-1-77007-446

for the latest overview (P. edulis & P. adspersus).

Also another great site for the sort of information you might need is AmphibiaWeb
http://www.amphibiaweb.org/index.html

for the link to Pyxicephalus see...


http://www.amphibiaweb.org/cgi-bin/a...re-submittedby

this extracts information from authoritative books.


regards,
michael

Dr Michael Cunningham
University of the Free State, Qwaqwa
Private Bag X13, Phuthaditjhaba 9866, SOUTH AFRICA
phone: +27-(0)58 718 5327, fax: +27-(0)58 718 5444

My comments back:

Michael,

Thanks for the heads up. Yes, the variation of the species populations across Africa could be a real problem in identification. And babies and juveniles are a nightmare to look for specific traits. Traits which may not be there yet or may be there but will fade to adulthood. Tough call.

Great info on the geographic location. I will make note of that. Any thoughts on P. obbianus?

Your last link leading to CalPhotos even shows some of the problems occurring with identification. In the first link, this photo is neither adspersus or edulis?
http://calphotos.berkeley.edu/cgi/im...1111+1111+1200

And in this second link, the photo on the left is very different from the photo on the right. What I am finding is the photo on the left is what is called edulis in the states, and the photo on the right is what is called edulis in Africa. What a mess.
http://calphotos.berkeley.edu/cgi/im...el-lifeform=ne

Thank you for your time.

Sincerely,

Jeff

Comments back: That I guess I don't see that they can be the same.

Hi Jeff,
At least in Southern Africa it isn't so hard to separate the two species - including the juveniles.

DuPreez & Carruthers give the following characters...
edulis usually has a white mark on the tympanum which is absent in adspersus
edulis has a pale interorbital bar (with pale transverse marks on the dorsal eyelid) which is absent in adspersus
edulis has the tympanum about 1 eye-width from the eye, in adspersus it is closer to twice this distance
edulis has irregular pale vertical bars on the upper lip which are absent from adspersus

in addition adspersus tend to have the orange axillary marks and mouth and elongate white marks along the dorsal skin folds

On all these characters the photos from CalAcad check out pretty well - I don't see that the edulis photos are necessarily from different species...it looks more like different individuals being photographed under different conditions and all correctly IDed.

P. adspersus is the type species of the genus (which is type genus of the family).

The type locality for P. adspersus is Cape Town (Cape of Good Hope) - which is actually ~400km SW of their distributional limit - meaning that this is where they were shipped or where the collectors were based (as were all collectors in Southern Africa of that period). At the time of description (1838) a few collectors had just reached as far as the Tropic of Capricorn but it is likely that this particular collection was made around Port Elizabeth on the South Coast.

The type locality for P. edulis is Tete on the Zambezi R in NW Mozambique.

These are the populations that must define the names and they are consistent with the above differences. The captive populations could be from anywhere and so their IDs may be dubious. I notice that one of the photos is referenced to Central South America - which is in error.

P. obbianus is an obscure taxon from Somalia - I've never read the literature on it and don't really know how it would compare.

The real problem is to discover whether P. anchietae from Mozambique near the Zambezi mouth is a valid species different from P. edulis and whether the species from Southern Africa are the same as those from North and West African savannas that are assigned to the same names.



End: Please let me know if there are any clarifying question you all would like me to send back.