Xenopus Borealis breeding

[TommyBoi]

Hey Terry, I am interested in knowing what "-ploids" my species are...like, tetraploid, octoploid, etc.... I have pairs of: Can you let me know, in regards to the species I have, thanks!!
I have Laevis; Borealis; Amieti; Boumbaensis; Clivii; Muelleri; and CO3. I would definitely like to attempt cross-breeding, just for my own colony, and who knows, we could end up with some beautiful frogs!

About 11 years ago, I had ordered several laevis x borealis hybrids, the males were sterile, and their spotting was washed out & elongated, but it was cool to have a hybrid...but, if I can breed a hybrid with the same "ploid" characteristics, then maybe the male offspring would possibly be fertile? And, I will def be attempting the amieti x boumbaensis spawn..I just have to wait and see if my boumbaensis are male or female, or 1 of each, etc... sincerely, DJ (Tom)

[tgampper]

Hey Terry, I am interested in knowing what "-ploids" my species are...like, tetraploid, octoploid, etc.... I have pairs of: Can you let me know, in regards to the species I have, thanks!!)

Interspecific hybridization among species in the genus Xenopus seems to be a rarity. However, there are some examples of a failure in reproductive barriers, allowing the occurrence of 3 known natural hybrids - laevis X gilli, laevis X muelleri and victorianus X borealis. The Station Experimentale de Zoologie at the University of Geneva (Switzerland) is the leader in producing a variety of Xenopus crosses. Hybrids are sterile.

I think the problem with producing viable hybrids goes beyond chromosome count, most of the Xenopus species has a very restricted range - laevis, muelleri, S. tropicalis and S. epitropicalis being exceptions. Restricted range increases the chances for reproductive isolation.

laevis: tetraploid (4 sets of 9 chromosomes = 36); laevis-subgroup
boeralis: tetraploid (4 sets of 9 chromosomes = 36); muelleri-subgroup
amieti: octoploid (8 sets of 9 chromosomes = 72); fraseri-like subgroup
boumbaensis: octoploid (8 sets of 9 chromosomes = 72); fraseri-like subgroup
clivii: tetraploid (4 sets of 9 chromosomes = 36); muelleri-subgroup
muelleri: tetraploid (4 sets of 9 chromosomes = 36); muelleri-subgroup
CO3: unknown taxa

It is possible that CO3 could be a newly described octoploid species from the Congo, sister taxon of X. vestitus:

Evans, B. J., Greenbaum, E., Kusamba, C., Carter, T. F., Tobias, M. L., Mendel, S. A. and Kelley, D. B. (2011), Description of a new octoploid frog species (Anura: Pipidae: Xenopus) from the Democratic Republic of the Congo, with a discussion of the biogeography of African clawed frogs in the Albertine Rift. Journal of Zoology, 283: 276–290. doi: 10.1111/j.1469-7998.2010.00769.x


Good luck with your breeding project

[TommyBoi]

Interspecific hybridization among species in the genus Xenopus seems to be a rarity. However, there are some examples of a failure in reproductive barriers, allowing the occurrence of 3 known natural hybrids - laevis X gilli, laevis X muelleri and victorianus X borealis. The Station Experimentale de Zoologie at the University of Geneva (Switzerland) is the leader in producing a variety of Xenopus crosses. Hybrids are sterile.

I think the problem with producing viable hybrids goes beyond chromosome count, most of the Xenopus species has a very restricted range - laevis, muelleri, S. tropicalis and S. epitropicalis being exceptions. Restricted range increases the chances for reproductive isolation.

laevis: tetraploid (4 sets of 9 chromosomes = 36); laevis-subgroup
boeralis: tetraploid (4 sets of 9 chromosomes = 36); muelleri-subgroup
amieti: octoploid (8 sets of 9 chromosomes = 72); fraseri-like subgroup
boumbaensis: octoploid (8 sets of 9 chromosomes = 72); fraseri-like subgroup
clivii: tetraploid (4 sets of 9 chromosomes = 36); muelleri-subgroup
muelleri: tetraploid (4 sets of 9 chromosomes = 36); muelleri-subgroup
CO3: unknown taxa

It is possible that CO3 could be a newly described octoploid species from the Congo, sister taxon of X. vestitus:

Evans, B. J., Greenbaum, E., Kusamba, C., Carter, T. F., Tobias, M. L., Mendel, S. A. and Kelley, D. B. (2011), Description of a new octoploid frog species (Anura: Pipidae: Xenopus) from the Democratic Republic of the Congo, with a discussion of the biogeography of African clawed frogs in the Albertine Rift. Journal of Zoology, 283: 276–290. doi: 10.1111/j.1469-7998.2010.00769.x


Good luck with your breeding project

Hey Terry, thanks for all the info! Of the frogs I have, what do u want to see me try to cross-breed, besides the amieti/boumbaensis? The boumbaensis are not sexually mature yet..maybe another couple months ;o) Right now, I have the x. clivii male by himself, and am gonna put a female in there tonight. Either the female clivii, or the female muelleri...what do u think?

[tgampper]

I would start out with clivii X clivii. That way you can have a pure breeding stock for the future. This particular species is quite rare on the market. Then you can cross breed them at a later time. You don't want to wear out the female on a venture that may or my not work.

[Geoff]

Of the frogs I have, what do u want to see me try to cross-breed, besides the amieti/boumbaensis?

In my opinion, for what it's worth, I don't think hybridisation is a sensible idea. If successful and the progeny get into the pet trade it carries the risk of people not knowing, or being confused about, what species they have. It just muddies the water unnecessarily (no pun intended). Hybridisation has created many identity problems in the tarantula hobby in the past (Brachypelma and Avicularia species). Likewise, international killifish societies discourage hybridisation for the same reason (Aphyosemion spp.). I believe also that poison dart frog hobbyists avoid hybridisation, particularly with D. tinctorius species. It's in the long-term interests of all these hobbies to make sure that species are kept as natural as possible.

[TommyBoi]

I was doing some reading, and tho a lot of hybrid-oriented articles refer to the males as being sterile, some mention that females are, or are very possibly fertile . If this is the case, then, my idea from many years ago, to produce as close to an Albino form of Borealis as possible, would be to Cross a Male X borealis w/ a female albino or retic...from the mature offspring, take a Female with albino traits, and breed her with a pure Male borealis, and those offspring would have heavier borealis traits, and include some albinos or reticulated form...a couple people over the years said they think that could be a possibility, not a definitive. But the only way to find out, is to attempt.
Btw, I want to let everyone know, the "cross-breeding" is not a full-time effort on my part...I want to achieve it a couple of times, partially for research, and partially out of curiosity, as to what those frogs would look like, and I would ONLY give them to friends,etc.
NO, I would not be taking the hybrids to petshops for that exact reason Geoff mentioned in the previous reply. All other breeding would be normal same-species breeding. As well, because Muelleri & borealis have such striking spotting & pigmentation, I am very curious to see what those hybrid offspring would look like, etc...I hope I haven't upset anyone by talking about it here..I apologize if I did.
Sincerely - tommy

[tgampper]

I was doing some reading, and tho a lot of hybrid-oriented articles refer to the males as being sterile, some mention that females are, or are very possibly fertile . If this is the case, then, my idea from many years ago, to produce as close to an Albino form of Borealis as possible, would be to Cross a Male X borealis w/ a female albino or retic...from the mature offspring, take a Female with albino traits, and breed her with a pure Male borealis, and those offspring would have heavier borealis traits, and include some albinos or reticulated form...a couple people over the years said they think that could be a possibility, not a definitive. But the only way to find out, is to attempt.

Sounds like you have an interesting project - getting an albino borealis. I haven't found any information on crossing a female albino laevis with a male borealis. What would be interesting to find out if the borealis sperm can penetrate the egg. Since the albino trait is probably recessive, you may get 100% heterozygous normal on the first generation. By breeding the male and female of generation one, it is likely you can have 25% albino and 50% heterozygous normal and 25% dominant normal, that is if Mendel is right Once again, your major problem will be overcoming generations of reproductive barriers.

Btw, I want to let everyone know, the "cross-breeding" is not a full-time effort on my part...I want to achieve it a couple of times, partially for research, and partially out of curiosity, as to what those frogs would look like, and I would ONLY give them to friends,etc.
NO, I would not be taking the hybrids to petshops for that exact reason Geoff mentioned in the previous reply. All other breeding would be normal same-species breeding. As well, because Muelleri & borealis have such striking spotting & pigmentation, I am very curious to see what those hybrid offspring would look like, etc...I hope I haven't upset anyone by talking about it here..I apologize if I did.
Sincerely - tommy

There is nothing wrong with being curious. I also have an interest in genetics and would love to breed my frogs, but just don't have the room or the time right now. However, it is important to maintain species integrity. There are now 19 species of Xenopus and 2 species of Silurana so far and several more yet to be described.