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My LFS acquired, last Wednesday, a batch of Corydoras that were sold to him as 'Bronze Corys'. And, to the uninitiated, they looked like Bronze Corys - they had the colour pattern that one would associate with a typical Bronze Cory.

However ...

First of all they appear to be much more delicate than a 'normal' Bronze Cory. And in particular seem to be very sensitive to pH swings - my LFS has experienced something like a 25% attrition rate over the past few days, while normally, Bronze Corys come in and are tough as old boots.

Second, I took a closer look at some of these 'Bronze Corys', and something doesn't sit right. So, I made a point of taking a couple of photos for comparison. And the results are quite interesting.

A 'normal' Bronze Cory has a fairly rounded snout and is quite tall at the 'shoulder', as this shot from PlanetCatfish illustrates quite nicely. However, several of the 'Bronze Corys' at my LFS have noticeably sloping and more angular snouts, and are elongated in comparison with the typical 'chunky' Bronze Cory body plan.

My shots are here]http://community.webshots.com/photo/336378434/522034785LHqUlu[/link] and [link=here ... in the second of these shots, we have a normal-ish Bronze Cory on the right, and what appears to be a "stretched" Bronze Cory to its left. Hmm, weird.

Any ideas anyone?


Last edited by Calilasseia at 12-Dec-2005 11:06

Panda Catfish fan and keeper/breeder since Christmas 2002

It is possible that it is related to the "Gold Shoulder/Stripe" corys, which are close relatives of Corydoras melanotaenia. Can you ask the LFS if they were wild-caught, and if so from where?

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I'm not your neighbor, you Bakersfield trash.

Hmm, I don't think offhand that they were wild caught, but I'll ask and see if I can gain extra info on the provenance of these fishes. It is weird though that [1] they're much more delicate seeming than the usual run of "Bronze Corys" (which, let's face it, have been domesticated for ages) and [2] have these visual differences upon closer examination. The fact that there are some genuine Bronze Corys mixed in there is also puzzling ...


Panda Catfish fan and keeper/breeder since Christmas 2002

If they are not wild caught, I'd say they are just inbred Corydoras aeneus from Southeast Asia. Inbred fish tend to be fragile due to their genetic weaknesses, and they can also appear very different from well-bred corys (having different color and shape).

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I'm not your neighbor, you Bakersfield trash.

I'm going to have to agree. Inbred fish will be weaker than your typical specimen, and can exhibit external differences as well. They are breeding Corydoras aeneus for different color morphs, so I wouldn't be surprised to see slight variations on body form as well.

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And when he gets to Heaven, to Saint Peter he will tell: "One more Marine reporting, Sir! I've served my time in Hell."

They do seem to be pretty variable as a species, heres a random selection of mine.

http://i12.photobucket.com/albums/a245/longhairedgit/IMG_4618.jpg

http://i12.photobucket.com/albums/a245/longhairedgit/IMG_0289.jpg

I even got this little fella free with a batch of bronze corys about 4 years ago.

http://i12.photobucket.com/albums/a245/longhairedgit/smallcory.jpg

They seem like happy little critters. That's a nice C. sodalis you have there, it seems like I always see sad-looking ones in the stores.

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And when he gets to Heaven, to Saint Peter he will tell: "One more Marine reporting, Sir! I've served my time in Hell."

Yeah , Ive never been able to find him a mate, they just dont stock them near me,but he lives with the 8 bronze cories as one of them, he goes where they go, he seems to have become extended family.They even do the touch all over with barbels thing, he even attempts mating. Gotta make do with what ya got

That's Corydoras napoensis, not Corydoras sodalis...

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I'm not your neighbor, you Bakersfield trash.

We've recieved llanos collected aeneus before(though labelled Venez., obviously not), and I noticed similar differences in head structure. I would consider it to be a variation admist the species, not particularly indicative of inbreeding.

Heh, serves me right for not paying attention. And he didn't even ask for an i.d.

Last edited by sirbooks at 13-Dec-2005 06:30

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And when he gets to Heaven, to Saint Peter he will tell: "One more Marine reporting, Sir! I've served my time in Hell."

LOL , easy mistake to make, they look pretty similar. I wasnt totally sure on the id myself considering Ive seen variants that look almost identical from both species. Whats the key identifiying characteristic BTW? I was a little in doubt as to is being a napoensis myself because ive seen temps recommended for them in the low 70's , but the tank its in is consistantly around the 80f mark, and its never had a sick day in its 4 year lifespan with me so far.



Last edited by longhairedgit at 15-Dec-2005 09:00

"Whats the key identifiying characteristic BTW?"

Mainly the shape of the fish... Corydoras napoensis is in the Elegans group and Corydoras sodalis is in the Julii group. They are shaped completely different.

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I'm not your neighbor, you Bakersfield trash.

Cheers for that, I guess I still have to get my eye in on corys a bit better.I can tell individual related snakes from the same species apart, can tell a rainbow species at 40 yards, but not corys from different species. Typical.