Imported as C. eques, but they aren't...

[bekateen]

Hi All,

Just got 15 of these corys from my LFS. They were imported from Czech Republic as

Corydoras eques

; ordered as 4-5cm TL, but arrived max 2.5cm TL.

Their body profile is low for an aeneus-type cory and their head is long, although their snout is not; their eyes seem large relative to head size. As they settle into quarantine, I see they are quite colorful: Their lower rear body has a distinct yellow-orange base color and the anterior half of the body has a strong green-gold iridescence. They also have gold/peach colored iridescent opercular plates and an iridescent spot above the pectoral fins. Finally they have an off-white (almost peach) iridescent eyebrow and a hint of an off white “laser”-like stripe across the top of the body.

Their color pattern reminds me of

Corydoras schultzei

, the Peru gold-stripe Cory. They also remind me of

Corydoras venezuelanus

, which in some places has been captive-bred into an unusually colorful strain that bears a loose resemblance to eques.

Although they are max 2.5 cm TL right now, even on this first night in my QT tank they are swimming together along the glass as if they might spawn... That would be a surprise as I expect they need to grow a lot before they mature. I can tell you my regular

Corydoras aeneus

don't look like this at same size and would never breed this small.

Attached are two photos, one with camera flash, the other without. Any ideas on ID?

Thanks, Eric

[MarlonnekeW]

Hi Eric,

I can't help you with identifying your cory's, but swimming together along the glass isn't necessarily spawning behavior. At lot of cory's do this when they are introduced to a new tank (it's a kind of stress behavior). So I wouldn't use that as a criterium to determine what species they are.

Marlonneke

[MChambers]

First picture has some resemblance to CW041, but those don't really match your description or the second picture.

[Karsten S.]

Hi,

it's always difficult to tell if they are not yet fully grown. I would exclude CW041 as well as C. eques.
I tend more towards to CW007, this species/form was considered to be C. eques in the past and also sold under this name.

Cheers,

[bekateen]

Thanks for your inputs. From CorydorasWorld, Ian suspects these are likely an aeneus-type or an aeneus hybrid. I'm going to allow them to grow out and see how they change.

Cheers, Eric

[Jools]

They look like the commercially bred form of C. venezuelanus.

Jools

[Karsten S.]

Hi Jools,

not really. Only by going with second picture I understand what you mean.
However, C. venezuelanus IMHO always shows some light area (not always brightly orange) between head and the dark body marking which also never extends till the caudal fin. This is the also valid for juveniles.

However, when they have fully grown it should also become more obvious by means of body proportions that they are something different. As they're coming from Czech Republic they could also be hybrids like Ian said, then we will possibly never know...

Cheers,

[Tony4143]

Man, this sucks for sure

[bekateen]

Recently heard from Ian, who examined a photo of fish from the Czech wholesaler (source). He said that the photo shown on the wholesaler's website is C. schultzei. I'll go with that until I have reason to do otherwise (e.g., if color pattern changes as they grow).

Thanks everyone for your input.

Cheers, Eric

[bekateen]

And they spawned today. Didn't collect the eggs. I'm letting the parents eat them. The adults are still really small. I want to allow the adults to grow up and develop full body shape and color before I even consider letting the eggs survive.

Why couldn't these have been real eques?

[bekateen]

New pictures. The fish are developing a yellow-orange underbelly, reminiscent of the yellow pectoral fins of

Corydoras sterbai

corys. The caudal fin also has a faint hint of this yellow-orange color, but not as brilliant as the lower body. The area behind the operculum is taking on a reddish color. The white/peach dorsal stripe is darkening up and is being obscured by a deep dark reddish hue over the top of the body. My photos probably won't do the fish justice.

[jac]

An old picture, about 10 years back when I kept en bred corydoras, of my group of C. Schultzei. You can see the adults have a much more pronounced laser stripe then the juveniles The breed like rabbits, I often had hundreds of fry. Didn't keep the long, just for that reason.....

[bekateen]

Thanks for sharing, @Jac. In real life (not just photos), did your fish have a reddish color?

And how long are your adults (SL) in that picture?

Cheers, Eric

[bekateen]

Here are several side-by-side photos of one of my Czech

Corydoras schultzei

(tentative) and a comparably sized

Corydoras aeneus

raised from eggs spawned in my own tanks about a month ago. To tell which is which, the aeneus has a lighter colored face, a taller body, and the melanized side blotch doesn't extend the length of the body. The stronger yellow-orange belly on the schultzei and the overall -darker and somewhat-dark-velvety-rusty-red dorsum of the schultzei is also evident in some of the photos but not all. The pale posterior area of my aeneus contrasts so strongly with the dark-bodied and yellow-bellied schultzei that the aeneus looks almost pink, although in real color it is not. Note also that the schultzei are already spawning at this size, but my aeneus is only a one-month-old juvie, nowhere close to sexually mature.

[jac]

Thanks for sharing, @Jac. In real life (not just photos), did your fish have a reddish color?

And how long are your adults (SL) in that picture?

Cheers, Eric

To be honest I can't really remember... They where big fish. I think around 6-7cm SL.
Mine didn't look like yours (on your latest pictures), and they had a really distinct laser stripe on their backs.

[bekateen]

Okay, thanks Jac.

[jac]

Your fish remind me of these

Corydoras venezuelanus

;)

[bekateen]

Your fish remind me of these

Corydoras venezuelanus

;)

Me too (that's why I mentioned it in my first post, LOL). And I can also see elements of schultzei as well. And to make matters worse, somebody else has suggested

Corydoras melanotaenia

, and I can see some of the yellow ventral color in that too, but I think the size is wrong and the body won't grow that long.

I think I won't know for sure until they are grown up. They are still very small. But what puzzles me is that at least one of them has already laid eggs. Are they going to stay small? Or did they just mature early?

Time will tell...

[bekateen]

Not too long ago I traded these odd schultzei back to the LFS and I picked up six melanized (black morph)

Corydoras schultzei

instead. They were rather sickly, scrawny and feeble when I got them, so I didn't post pictures at the time. They've been in quarantine a couple of weeks now, and they have really filled in nicely and grown a bit since I got them, so I captured a short video of them today.

I'm not very interested in strain-bred fish (that's why I got rid of the "questionable" regular schultzei), but I gotta say these black schultzei are really stunning. I wonder what a tank filled with (non-breeding) black schultzei and albino aeneus would look like. I bet it would look really neat (better than any glowfish! LOL)

Cheers, Eric

Direct link to Youtube: Corydoras schultzei black morph - new acquisition



And on a lighter note, it's time to celebrate. My YouTube videos just surpassed 10,000 views (collectively) today... Can't really call the videos "viral," but I'm pretty sure I'm infected with a few viruses myself, if that counts! Anyway, thanks for watching!

[Carolus]

I actually have albino aeneus and black schultzei in my community tank, and it is pretty neat

[bekateen]

I actually have albino aeneus and black schultzei in my community tank, and it is pretty neat

What color substrate do you have them on? I would imagine going to either extreme (black or white), or to a neutral medium gray sand might be good. But not a mixed-color gray sand, rather a very homogeneous color sand. Otherwise, it just looks like camouflage.

Cheers, Eric

[Carolus]

I have a very pale sand substrate, sort of like a broken white. Although in hindsight, I think regular pale brown sand would make the albino's pop out more than they do in my tank atm. Then both the albinos and blacks would really jump out at you I think.