Unexpected (undesired) livebearer cross?

[Kat_Rigel]

Hi all, I have a question regarding livebearer crosses, specifically Limia perugiae and Characadon lateralis. I was chatting with a friend at my fish meeting yesterday and mentioned that my lateralis fry tend to have a spot of the dorsal fin, which my friend's did not have. When I got home and looked in my tank, I could see some lateralis that looked like the adults, and some with a paler complexion and that dorsal spot. I also realized that I have a single Limia perugaie male in there, and... there is a prominent dorsal spot on that fin. I didn't think twice about putting them in there together because they are in different genus, which means they should not be able to breed. I am wondering if the fry with the dorsal spots are crosses of lateralis and perugaie (I hope not!) I am trying to look up how many chromosomes each species have but haven't had any luck. (If they are different, there's no way the spotted fry could be a perugaie x lateralis cross.)
I'm a little upset because I have ZERO interest in crossing these species; lateralis is a goodeid. Does anyone have any insight into this? 

Tank contains: male Limia perugaie, Characadon lateralis colony, male Limia nigrofasciatus, Corydoras aeneus, Kyathit danio, heavily planted. There are no female limias.

Above: Adult Characadon lateralis

Above: A normal lateralis fry

Above: Limia perugaie male. Tough to see that spot on the dorsal fin but if you look closely, it's there.

Above: The suspicious lateralis fry with a dorsal spot. The pale body would be consistent with a cross. No lateral spots makes me suspicious as well.

[TheSwissAquarist]

@Fish Folk has been dabbling in rare livebearers; maybe he can help …?

[Fish Folk]

I suspect that your Limia perugaie is actually a female. She’s dropping fry here and there. They can hold on to milt from prior spawnings for a long time.

Male LPs have a black rim around dorsal and caudal fins. Female LPs have that black spot at the back of their dorsal fin — much like a Florida Flagfish.

[Kat_Rigel]

On 11/21/2022 at 3:37 AM, Fish Folk said:

I suspect that your Limia perugaie is actually a female. She’s dropping fry here and there. They can hold on to milt from prior spawnings for a long time.

Male LPs have a black rim around dorsal and caudal fins. Female LPs have that black spot at the back of their dorsal fin — much like a Florida Flagfish.

Hm, I don't think the limia I'm seeing is female, as it does have a very prominent gondopodium, and it has a shiny iridescence that I havent seen on females. (I'll check again og course- Ive been fooled before!) BUT that did give me another idea- this tank is VERY densely planted, so perhaps there is a female hiding in there that I just haven't seen?

I'll take another look at the suspicious LP to confirm its sex. But do yo uagree that it's very unlikely that the two species crossed?

[Fish Folk]

On 11/21/2022 at 10:18 AM, Kat_Rigel said:

But do yo uagree that it's very unlikely that the two species crossed?

I’m not positive. Greg Sage at Select Aquatics would be who I would ask.

The fact that they don’t share any binomials inclines me to think maybe not… but we do see hybrids between some Guppy / Molly pairs. 

[TheSwissAquarist]

On 11/21/2022 at 4:25 PM, Fish Folk said:

I’m not positive. Greg Sage at Select Aquatics would be who I would ask.

The fact that they don’t share any binomials inclines me to think maybe not… but we do see hybrids between some Guppy / Molly pairs. 

Endler/Guppy, Guppy/Swordtail, Platy/Swordtail are pretty common. 😕

[Odd Duck]

On 11/21/2022 at 9:26 AM, TheSwissAquarist said:

Endler/Guppy, Guppy/Swordtail, Platy/Swordtail are pretty common. 😕

I don’t think guppies can cross with swordtails.  Endlers and guppies are in the same genus, same with mollies despite the size difference.  Platies and swordtails are in the same genus.  Guppies and swordtails are different genus, highly unlikely for them to crossbreed.  I won’t say impossible since there are some species that can hybridize across genus - mostly in the Central American cichlid species or within South American cichlid species.

 @Kat_Rigel, I have zero expertise on these species, but it seems unlikely they would cross being different genus.  I think @Fish Folkis right about your fish and has the right idea about consulting an expert.  You could also have a pseudohermaphrodite, too, looking like a male, but internally female.  Or just a damaged anal fin that looks like a gonopodium?  Talking to someone with expertise in the particular fish species in question will get you a more definitive answer.

[TheSwissAquarist]

On 11/21/2022 at 7:42 PM, Odd Duck said:

don’t think guppies can cross with swordtails.  Endlers and guppies are in the same genus, same with mollies despite the size difference.  Platies and swordtails are in the same genus.  Guppies and swordtails are different genus, highly unlikely for them to crossbreed

I’ve observed it in one of my first tanks, and a couple of fish friends have also seen it.

[Odd Duck]

On 11/21/2022 at 11:46 PM, TheSwissAquarist said:

I’ve observed it in one of my first tanks, and a couple of fish friends have also seen it.

Do you have pics? That would definitely be a first.  I can’t find anything with a google search.  I did some searching triggered by a thread a while back about hybrids across genus and they are considered very rare among animals (less rare in plants) but certainly not unheard of.  They are typically across closely related genus, like the cichlids mentioned.  If you can document this hybrid of guppy and swordtail, you should write it up since it would be the first documented case as far as I can find.  Considering that swordtails and guppies have been kept in aquariums together for decades and decades, it would be unusual to suddenly find multiple cases.

[TheSwissAquarist]

On 11/22/2022 at 7:15 AM, Odd Duck said:

Do you have pics? That would definitely be a first.  I can’t find anything with a google search.  I did some searching triggered by a thread a while back about hybrids across genus and they are considered very rare among animals (less rare in plants) but certainly not unheard of.  They are typically across closely related genus, like the cichlids mentioned.  If you can document this hybrid of guppy and swordtail, you should write it up since it would be the first documented case as far as I can find.  Considering that swordtails and guppies have been kept in aquariums together for decades and decades, it would be unusual to suddenly find multiple cases.

I'll check with friends at school, but I'll willingly admit that back then (≈5-4 years ago?) we all wanted what the other one had and we all knew nothing about cycling 😂. For us it was: add substrate & plants, fill up, wait 2 weeks and add fish. Surprisingly we actually had success, but I'm the only one who's really delved deeper into the hobby. 🤷‍♂️. I'm really going to have to look for pics, as we were all about 11-12 at the time and we didn't have phones. 

Maybe swordtails are more interested in baby making on this side of the Atlantic ?🤣

[Odd Duck]

My guess is you actually had some swordtail guppies which are a guppy tail variety but not actually a hybrid of guppy and swordtail.  Might have been some endler in the mix, too.  But very unlikely to be a true intergeneric hybrid.  I’ll not say never any chance of it because stranger things have happened.  It’s just highly unlikely.  I’d sure like to see pics if you can find them.

I’ll help you right it up and put you in touch with the right people to get it published if you have proof.

[TheSwissAquarist]

On 11/22/2022 at 7:47 AM, Odd Duck said:

My guess is you actually had some swordtail guppies which are a guppy tail variety but not actually a hybrid of guppy and swordtail.  Might have been some endler in the mix, too.  But very unlikely to be a true intergeneric hybrid.  I’ll not say never any chance of it because stranger things have happened.  It’s just highly unlikely.  I’d sure like to see pics if you can find them.

Could be true...I distinctly remember some very muscular guppies though...intriguing!

[Kat_Rigel]

On 11/21/2022 at 10:42 AM, Odd Duck said:

 You could also have a pseudohermaphrodite, too, looking like a male, but internally female.

Thanks, all! Seems like we mostly agree that while quite unlikely, it is remotely possible that it's a cross. I'm intrigued by the idea that the Limia perugaie I have is a pseudohermaphrodite- that would be strange too, but somehow I think more likely. I'll follow up with some folks more educated than I to see if if I can garner some answers. Last question though, anyone know where I can look up how many chromosomes each species has? I keep finding a lot of papers on the Limia P., but none regarding their chromosome count. I'm certain someone out there knows; certainly the researchers writing those papers had access to the information. I thought there would be some sort of database.
Anyway, thank you all very much! I appreciate the insight.

 

[TheSwissAquarist]

On 11/22/2022 at 7:47 AM, Odd Duck said:

My guess is you actually had some swordtail guppies which are a guppy tail variety but not actually a hybrid of guppy and swordtail.  Might have been some endler in the mix, too.  But very unlikely to be a true intergeneric hybrid.  I’ll not say never any chance of it because stranger things have happened.  It’s just highly unlikely.  I’d sure like to see pics if you can find them.

I’ll help you right it up and put you in touch with the right people to get it published if you have proof.

No pics 🤦‍♂️🤦‍♂️🤦‍♂️! Feeling a bit stupid now… turns out it was a guppy with a sort of elongation on the bottom of their fin. Wether it was a hybrid is up for grabs. Sorry!!

[Odd Duck]

On 11/22/2022 at 10:13 AM, TheSwissAquarist said:

No pics 🤦‍♂️🤦‍♂️🤦‍♂️! Feeling a bit stupid now… turns out it was a guppy with a sort of elongation on the bottom of their fin. Wether it was a hybrid is up for grabs. Sorry!!

No worries!  Things are often different from what we remember from when we were younger.

There are guppies with sword tails and double swords (top and/or bottom), ribbon tails (super long sword like extension), spade tails, delta tails, etc, etc.  I might have a guppy variety pic saved, let me check.

Nope, must not have saved it and now I can’t find the one I was thinking about.  But I did find this easy graphic that shows various tail shapes.

 

 

[PineSong]

Big sigh of relief from me about the guppies and swordtails not being able to hybridize--I have four guppy males in my swordtail tank and would be shocked and dismayed if that combo produced fry. I used to have a lower-sword only swordtail guppy, so I can see how kids might think he was a mix of the two species.

[sebdeserio]

Not only are Characadon and Limia different genera but the males in both species have different sexual organs with goodeids having andropodiums and Limia having gonopodiums. IMO there's 0% chance it's a hybrid between the 2 species.

 

[Kat_Rigel]

On 11/22/2022 at 8:08 PM, sebdeserio said:

Not only are Characadon and Limia different genera but the males in both species have different sexual organs with goodeids having andropodiums and Limia having gonopodiums. IMO there's 0% chance it's a hybrid between the 2 species.

 

AHA! I knew there must be more proof than just the genus. Thank you so much for this info, I will definitely be looking into the organs you mentioned to educate myself further.

Oh, and side note to @TheSwissAquarist- I have much more respect for people who say, "whoops! I made a mistake!" than people who dig in their heels. No harm here!

[TheSwissAquarist]

On 11/23/2022 at 6:32 AM, Kat_Rigel said:

AHA! I knew there must be more proof than just the genus. Thank you so much for this info, I will definitely be looking into the organs you mentioned to educate myself further.

Oh, and side note to @TheSwissAquarist- I have much more respect for people who say, "whoops! I made a mistake!" than people who dig in their heels. No harm here!

Rather do that than anything else…otherwise it tends to ruin stuff!

[sebdeserio]

On 11/23/2022 at 12:32 AM, Kat_Rigel said:

AHA! I knew there must be more proof than just the genus. Thank you so much for this info, I will definitely be looking into the organs you mentioned to educate myself further.

Oh, and side note to @TheSwissAquarist- I have much more respect for people who say, "whoops! I made a mistake!" than people who dig in their heels. No harm here!

No problem! Limia are known to hybridize with endlers and guppies so although being in a different genus usually means they can't hybridize there's some exceptions. They're both cool uncommon livebearers it's good you're having success with the Characadon.

[mountaintoppufferkeeper]

@Kat_Rigel I am of course slightly late to the party again but ..... to me it seems plausible that an interfamilial hybrid between the family Poeciliidae (limia) and the family Goodeidae (characodon) could occur since the way they reproduce is similar combined with the rare instances were interfamilial hybrids within an Order of fish have occurred in the past. Nature will find a way so to speak. I have no direct experience in this type of event but what you are observing is not that far off of what unintentionally created the "sturddlefish" in 2020 within the Order Acipenseriformes.

The "sturddlefish" was the result of an unintended hybridization of Russian Sturgeon (Acipenser gueldenstaedtii) and American Paddlefish (Polyodon spathula) and was reported in Genes magazine (original peer reviewed article: https://www.mdpi.com/2073-4425/11/7/753 ). The scientists involved were not intending to produce this hybrid and did not expect it would be possible within an order following a genetic break between the families approximated 184 million years ago. 

I would assume it is a matter of the genetics combining within these two families of the Order Cyprinodontiformes to make surviving offspring. It would seem unlikely that any hybrid offspring would be fertile unless some crazy level of genetic mix worked out but I wouldn't totally dismiss it as a very rare but not totally impossible outcome. Genetics is fairly fascinating topic when you get to looking at it even casually.

 

Links

 https://www.livescience.com/impossible-hybrid-fish-created.html

Mexican goodeid fishes of the genus Characodon, with description of a new species. American Museum novitates ; no. 2851
Smith, Michael Leonard.; Miller, Robert Rush, 1916-
https://digitallibrary.amnh.org/handle/2246/5248

Reproductive failure of dominant males in the poeciliid fish Limia perugiae determined by DNA fingerprinting.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC47076/

 

Edited November 23, 2022 by mountaintoppufferkeeper

[Kat_Rigel]

@mountaintoppufferkeeper Thank you for the additional insight! I did have some uncertainty about the possible cross, even with the genus difference, as you mentioned. A lot of the goodeids are getting reclassified over and over again as we learn more about them, which made me wonder about how closely related the fish actually are.

VERY interesting example with the sturddlefish, I'll definitely be reading that article! Shocking that such different species would cross!