Question for the Corydoras experts

[cawnov]

Since C.aeneus is the most commonly encountered Corydora in aquarium trade I'm assuming that most are captive raised/aquacultured.
My question is this; From which regional type (species?) is the most common form of C.aeneus most likely derived from?
Venezuela? Trinidad? Elsewhere?

Do you think that cultured C.aeneus are true species (not human created hybrids)?

I'm thinking that earlier in the aquarium trade species may have been mixed but later they were cultured from a form easily available from a specific region.

What do you think?
Anybody have pics of wild types of C.aeneus?

[Richard B]

I am certainly not a cory expert but the type specimen is from Trinidad & a wild photo is here
http://www.planetcatfish.com/catelog/im ... ge_id=7529

It is a wide ranging species & no doubt there are some regional differences. Wild specimens are occasionally imported but the vast majority of specimens in the trade are commercially bred. I believe the commercially available ones are genuine aeneus & not hybrids at all. Many successive generations of commercially bred fish may produce something that has differences from wild fish even though they are the same species - look at goldfish as an example.

[MatsP]

I'm by no means an expert, but I would say that it's unlikely that we can find out where the original species of the current tank-bred fish are from. The current tank-bred fish are probably 20-40 years worth of tank bred generations away from the wild-fish - possibly with the odd injection of wild-caught specimens [and whether these are from the same source or not is of course a bit of an interesting question - perhaps not].

--
Mats

[cawnov]

Using mtDNA and microsatellite sequences from natural populations and fish collections we might be able to find out the primary source population. It can be done. But most likely that will not happen.

[MatsP]

Using mtDNA and microsatellite sequences from natural populations and fish collections we might be able to find out the primary source population. It can be done. But most likely that will not happen.

Oh, yes indeed. It is technically possible, but as you say, very unlikely that it will actually happen.

--
Mats

[CoryWally]

As you're probably aware there are a number of aeneus types from across S.America, which could be separate species (e.g. 'schultzei', 'venezualanus', 'macrosteus' etc), the only one which can strictly be called aeneus are those from the type locality (Trinidad). I suspect most of the commercially bred ones are a Brazillian type similar to the true aeneus. If you're interested in getting a true strain there are a number of breeders who hold Trinidadian aeneus or venezualanus. Check CorydorasWorld (sorry for the blatent plug) for more information and contact with dedicated Cory keepers across the world.

There will be a lecture at the Catfish Study Group convention from Marcos Alexandrou of Bangor University (U.K.), where a lot of Corydoras sequencing has been carried out. I'm sure he could help address the question, and they may have sequenced shop bought aeneus as a comparison with 'known' species.

Cheers,
Mark.

[cawnov]

Excellent. Thank you so much for that information.
Does the Catfish Study Group typically publish conference papers?

[medaka]

Sorry to move off topic but!
cawnov wrote:

Does the Catfish Study Group typically publish conference papers?

The quick answer here is no.
The problem is that most of the committee have on going duties over the course of the convention weekend, coupled with the speakers only having refresher type notes with them when then are addressing the delegates, makes it extremely difficult to come up with a written report that can be published in the groups journal.
What the CSG needs is a member that has some sort of experience in doing reports from events to volunteer and a person that is also willing to give their time, etc; to attending group and committee meetings during the coarse of a year; for only satisfaction as a job well done as reward/payment.

However; this has been mooted loosely around at committee stage in the last year.
Years ago such notes were taken at club meetings but these were mainly taken at a normal group meeting, and then released to members via its quarterly journal. But once that person stopped taking notes, no volunteer with the necessary aptitude could be found to carry on doing so.