Cory ID

[itiwhetu]

And it may just be the longfin C.paleatus and so just breed away. It is more likely to be that than a hybrid between two species, I feel.

 

[gabrielgalhano]

Species within a genus should be descended from the same ancestor, in which case the genus is termed monophyletic. The genus Corydoras is polyphyletic, which means the 160-odd species (not including the C and CW numbers) now classified in this genus are not all descended from the same ancestor according to phylogenetic analysis. There are nine lineages in the genus as it now exists, and one of these has four clades. The issue here is that C. paleatus and C. longipinnis are in lineage 6. Species within the same genus (or lineage here) can easily hybridize. Generally they will not do this in nature because they either are not living in the same geographical habitat, or if they were, they tend not to hybridize (there are examples proving this among other fishes, like the two lineages of Carnegiella strigata (Marble Hatchetfish) that do occur together in only one area but have never cross-bred). Stuffed into an aquarium, things can be different. If you have males and females of both species (of Corydoras) they will not cross-breed, but if there is/are only one gender of one of the species and the other species has the alternate gender, hybridization is much more likely to occur. I have had this a couple of times. I will just make sure the fry never get into the hobby outside my tanks.

Ian Fuller's reasoning why this hybridization is not a good thing...

In nature some species do occasionally cross, especially at a time when severe conditions bring species together that would not normally be found in the same place. This is known in science as speciating.​

​

In the Hobby it species would have to be purposely put together and that would create unnatural crosses, and then we would end up with these hybrids expanding into the hobby and ultimately spoiling the two crossed species.​

​

There are probably in excess of 300 naturally occurring Corydoradinae species, many of which are in danger of becoming extinct in their natural homes and I would like to see efforts being made to preserve these species. I realise that it will be an almost impossible task to try and reinstate aquarium bred specimens back into their natural homes, mainly because these are being or have been destroyed.​

I am not going to allow this to be a drawn out discussion. I do not agree with hobby or commercially produced hybrids so such discussions here are banned.​

Another aspect of this is that with the increasing destruction of fish habitats, the day may well come when the species in aquarists' tanks are all we have left of that species. It would indeed be sad if we had not only destroyed their habitat but then polluted the species through our own ignorance or greed. Just look at "balloon" fish, or "glo" fish to see the extent of this greed.

I just came across my notes with more from Ian on these two species, so I will add this paragraph.

One example we have C. longipinnis, which has long extending dorsal and pectoral fins, and C. paleatus that has what we would call normal proportioned fins. C. longipinnis was only described by Knaack in 2007 and prior to that both species would and were considered as C. paleatus and as such both species are now in commercial breeding stocks, this is why we see short and long finned varieties in the same batches of young.​

Yup, I totally agree that it would be sad the destruction of species through our ignorance and greed. Thank you for what you shared! I'll be taking everything in consideration!

 

[itiwhetu]

With all of that information from Byron. The best thing you can do is cull the fish. As you don't want it breeding and if you have other Cory's you won't be able to prevent this fish cross breeding.

 

[DoubleDutch]

Ian Fuller has responded, and as I suspected, the pictured fish involves another species, Corydoras longipinnis Knaack 2007. Here are Ian's comments, and a follow-up question from another member.

C. longipinnis, they are almost identical on colour pattern, but C. paleatus does not naturally have the extended dorsal fin rays.​

Before C. longipinnis was described both species were mixed in breeding stocks in fish farms and subsequently produced what are actually hybrids. This is why there are short and long finned specimens appearing in commercially bred stock.​

Do not make the mistake and think that this is the same as the man made mutant long straggly finned fish being mass produced. All the fins of these fish are long and straggly.​

​

Ian, how does one differentiate between longipinnis and paleatus hybrids?​

​

You don't. The only way is to get wild stock of each.​

The one in the pic is a longfin C.paleatus though. Longipinnis don't have such elongated pelvic fins.

Personally I don't like longfins. Some even have difficulty to swim and to get enough food.

But there seems to be an urge to breed longfins (or balloonvariaties) of every species nowadays.

C.paleatus are great fish !!

 

[itiwhetu]

The one in the pic is a longfin C.paleatus though. Longipinnis don't have such elongated pelvic fins.

Personally I don't like longfins. Some even have difficulty to swim and to get enough food.

But there seems to be an urge to breed longfins (or balloonvariaties) of every species nowadays.

C.paleatus are great fish !!

Thank you @DoubleDutch. My thoughts exactly

 

[gabrielgalhano]

The one in the pic is a longfin C.paleatus though. Longipinnis don't have such elongated pelvic fins.

Personally I don't like longfins. Some even have difficulty to swim and to get enough food.

But there seems to be an urge to breed longfins (or balloonvariaties) of every species nowadays.

C.paleatus are great fish !!

I'm very confused now
I'll try to post a picture of these 2 along with the ones I already had before I buy these ones. Maybe it helps.

Mine don't seem to have much difficulty in swimming or getting food. On the contrary they seem to be the more active swimmers in that tank

They're amazing! The second species of cory catfish that I own

 

[gabrielgalhano]

With all of that information from Byron. The best thing you can do is cull the fish. As you don't want it breeding and if you have other Cory's you won't be able to prevent this fish cross breeding.

I will not cull my fish. If they turn out to be hybrids I'll just set up a smaller tank for them with some guppies or something, since I believe they're both males they wont be breeding.

 

[itiwhetu]

I will not cull my fish. If they turn out to be hybrids I'll just set up a smaller tank for them with some guppies or something, since I believe they're both males they wont be breeding.

How will you ever really know, just enjoy your fish. Let them do what they want to do. On the big scheme of things your two fish aren't going to make any difference.

 

[gabrielgalhano]

Here are some pictures of my supposedly C. paleatus.

 

[DoubleDutch]

Here are some pictures of my supposedly C. paleatus.

View attachment 142930

View attachment 142931

View attachment 142932

All C.paleatus with one linebred longfinvariaty to me. Could definitely be, as Byron mentioned, C.longipinnis was used to breed the longfin in them, but the pelvic fins of longipinnis are not as long as these.

 

[itiwhetu]

You are never going to know exactly their genetical make up so just let them breed if they want to and enjoy.

 

[itiwhetu]

Species within a genus should be descended from the same ancestor, in which case the genus is termed monophyletic. The genus Corydoras is polyphyletic, which means the 160-odd species (not including the C and CW numbers) now classified in this genus are not all descended from the same ancestor according to phylogenetic analysis. There are nine lineages in the genus as it now exists, and one of these has four clades. The issue here is that C. paleatus and C. longipinnis are in lineage 6. Species within the same genus (or lineage here) can easily hybridize. Generally they will not do this in nature because they either are not living in the same geographical habitat, or if they were, they tend not to hybridize (there are examples proving this among other fishes, like the two lineages of Carnegiella strigata (Marble Hatchetfish) that do occur together in only one area but have never cross-bred). Stuffed into an aquarium, things can be different. If you have males and females of both species (of Corydoras) they will not cross-breed, but if there is/are only one gender of one of the species and the other species has the alternate gender, hybridization is much more likely to occur. I have had this a couple of times. I will just make sure the fry never get into the hobby outside my tanks.

Ian Fuller's reasoning why this hybridization is not a good thing...

In nature some species do occasionally cross, especially at a time when severe conditions bring species together that would not normally be found in the same place. This is known in science as speciating.​

​

In the Hobby it species would have to be purposely put together and that would create unnatural crosses, and then we would end up with these hybrids expanding into the hobby and ultimately spoiling the two crossed species.​

​

There are probably in excess of 300 naturally occurring Corydoradinae species, many of which are in danger of becoming extinct in their natural homes and I would like to see efforts being made to preserve these species. I realise that it will be an almost impossible task to try and reinstate aquarium bred specimens back into their natural homes, mainly because these are being or have been destroyed.​

I am not going to allow this to be a drawn out discussion. I do not agree with hobby or commercially produced hybrids so such discussions here are banned.​

Another aspect of this is that with the increasing destruction of fish habitats, the day may well come when the species in aquarists' tanks are all we have left of that species. It would indeed be sad if we had not only destroyed their habitat but then polluted the species through our own ignorance or greed. Just look at "balloon" fish, or "glo" fish to see the extent of this greed.

I just came across my notes with more from Ian on these two species, so I will add this paragraph.

One example we have C. longipinnis, which has long extending dorsal and pectoral fins, and C. paleatus that has what we would call normal proportioned fins. C. longipinnis was only described by Knaack in 2007 and prior to that both species would and were considered as C. paleatus and as such both species are now in commercial breeding stocks, this is why we see short and long finned varieties in the same batches of young.​

So the purpose of this post is exactly what. What are you trying to say.

 

[DoubleDutch]

Problem with a lot of species is that several were long be seen as the same species and got seperated species later.

C.aeneus - C.venezuelanus - C.schultzei were earlier considered as C.aeneus. When they mated it wasn't considered crossbreeding.
That's the way green Aeneus were bred (there is a natural type also btw).

The seperate species C.macrosteus (huge Corys) is now C.aeneus again.

Same with C.paleatus and C.longipinnis.
Now the offspring of these are considered crrossbreds / hybrids. Earlier they weren't

So some fish got crossbred without the intention to do so.

 

[itiwhetu]

Problem with a lot of species is that several were long be seen as the same species and got seperated species later.

C.aeneus - C.venezuelanus - C.schultzei were earlier considered as C.aeneus. When they mated it wasn't considered crossbreeding.
That's the way green Aeneus were bred (there is a natural type also btw).

The seperate species C.macrosteus (huge Corys) is now C.aeneus again.

Same with C.paleatus and C.longipinnis.
Now the offspring of these are considered crrossbreds / hybrids. Earlier they weren't

So some fish got crossbred without the intention to do so.

And the problem with this is??

 

[DoubleDutch]

And the problem with this is??I don't reval

It is an explanation on Byron's post about "hybrids". Several fish that we now see as hybrids weren't a few years back.

Green Corys in fact are hybrids (aeneus × venezuelanus) but weren't seen as such earlier.

The longfin C.paleatus might be a hybrid (paleatus × lingipinnis) but wasn't seen as such some years back.

Coryfan's try to keep the species "clean" which is rather impossible cause of this legacy.