Not Corydoras agassizii? Is it C. schwartzi?

[bekateen]

Hi All,
I recently purchased a catfish (shown in the two pictures), sold as C. agassizii, from a pet store that I've previously considered pretty reliable on fish names. But I already own several cats which I believe are agassizii (shown in a group of 3) and this new cat does not look the same.

My newly purchased cory - not agassizii?

Another view of my newly purchased cory - not agassizii?

What I believe actually are C. agassizii

Is my new fish possibly an odd looking agassizii? or is it more likely a different species, perhaps C. schwartzi, C. pulcher, C. ornatus, C. sp. (C133) (or something else)? Like my other agassizii, this new cat has the upside-down black V through the eyes and face, and the yellow-tan streak just behind that. But unlike my other agassizii, the new cat has three distinct stripes on the side and relatively little spotting over the body; also the new cat has a white front dorsal spine (not black), it has a much-reduced black spot on the dorsal fin, and that dorsal black spot does not extend down very far onto the body. Thanks for any help you can offer!
Eric
P.S. If it is a different species, is there any chance that they would interbreed? How common is that among the Corys?

[FerocactusLatispinus]

To me it looks most like a C. ornatus: it has that stout, white dorsal spine; preceeding that, a better-defined, brighter stripe leading behind the eye when compared to C. agassizii; the snout is also slightly more elongated and compressed than an agassizii's; the three distinct black lateral stripes definitely aren't found in C. agassizii or C. parallelus.

As for corydoras hybridization, I don't really know how common that is. I have a C. sodalis and a C. paleatus, and both prefer to hang around, chase, and nudge each other, rather than be with my C. aeneus, together or apart. They are all about the same size, and it makes me wonder what a sodalis x paleatus hybrid would look like; I'd give it a "saleatus" or "podalis" common name!

[CoryfanAad]

It looks like a Schwartzi-variaty mentioned in my Aqualog-book (I lnow this isn't very accurate) BTW : are you 100% sure the others are agassizii ???

[FerocactusLatispinus]

I've kept one C. agassizii, but he has passed away several months ago. Personally, I think the ones in the photo of the first post are actual specimens of that species; in most cases, pattern isn't quite as stable, when it comes to identifying a species, as morphological characteristics; when it comes to Callichthyids, I tend to focus on snout length and shape, caudal fin form, dorsal profile, and pattern. I've found this to be the most reliable method (for me anyway).

[CoryfanAad]

Okay. I know the pattern-ID isn't very reliable. My thoughts went to Ambiacus (the other ones !) but I defo could be wrong. Hoping specialists will jump in!

[bekateen]

As for corydoras hybridization, I don't really know how common that is. I have a C. sodalis and a C. paleatus, and both prefer to hang around, chase, and nudge each other, rather than be with my C. aeneus, together or apart. They are all about the same size, and it makes me wonder what a sodalis x paleatus hybrid would look like; I'd give it a "saleatus" or "podalis" common name!

Not counting my new unknown, I have a total of five C. agassizii. In the same tank I have three C. trilineatus and four albino C. aeneus. Both of these species have spawned many times in this community setting. The agassizii don't show any interest in the aeneus, but they constantly follow the trilineatus, especially when the trilineatus are spawning (and the trilineatus seem to like the company) - even though the agassizii are much larger than the trilineatus. Unfortunately, the agassizii have never spawned with each other, or, as far as I can tell, actually tried to spawn with the trilineatus when the female is laying eggs. At least so far, all the young I've gotten grow up to be typical trilineatus.

[Karsten S.]

Hi,

I don't think that the pictures show C. agassizii, I would also favour C. ambiacus.
The problem with these species is that they are very variable and many species/forms/numbers are sold under these names and that you don't have much of really reliable picture reference.

The other ones are certainly no C. agassizii, I don't think they are actually C. ornatus which are afaik rather seldom and far away from the commercial fishing location. So it's very unlikely to get them accidentally.
I tend more towards C 141.

Cheers,

[bekateen]

Hi Karsten, Your idea that the mystery cat may be Corydoras sp. (C141) is a be good possibility. One thing that bothers me about the other likely spp. (ornatus and schwartzi) is that the photos tend to show them with two lateral stripes (well, ornatus has 3, but the uppermost is very high on the fish's flank and doesn't reach the tail), but my fish and C141 have three stripes that reach the tail.

Left: mystery Cory; Right: mystery Cory (below) and agassizii (above)

As for my other cats (agassizii), I'm not convinced that they are ambiacus and not agassizii. At seriouslyfish dot com (am I allowed to mention their web name in a PlanetCatfish post?) they give Steindachner's original descriptions of both spp.; these are sufficiently ambiguous as to be unhelpful. The original description of agassizii lists the anal fin as unmarked, but then the original drawing shows small spots on the anal fin. My fish have similarly spotted anal fins; moreover, the pics of agassizii on planetcatfish.com show the same anal spots. So I'm still leaning toward these being agassizii.

Two views of agassizii

[FerocactusLatispinus]

For comparisons regarding the unidentified cory, I particularly refer to the second/central image posted in the original post. Utilizing all images on each species' respective page, I feel that this is a very nice (and convenient) photo from the Cat-eLog comparing C. ornatus and C. sp. (C141):

http://www.planetcatfish.com/common/ima ... e_id=14949

If you compare the longitudinal position of the eye in relation to the operculum (gill cover), you'll see that in C. ornatus, the anterior edge of the operculum does not proceed as far anteriorly as it does in C. sp. (C141). Also, in C. ornatus, the operculum has a slightly more elongated profile in comparison. Snout (rostrum) contour in C. ornatus is typically distinct: the snout itself projects outward to a greater degree, giving it more of a "shoveled" appearance. The caudal fin in C. ornatus is not as deeply forked.

In contrast, C. sp. (C141) does have a stouter dorsal fin spine, is a bit longer, and is usually covered by paler skin than is seen in C. ornatus. As far as pattern on the caudal fin goes, the dark longitudinal bars are far more prominent here in C. sp. (C141). Finally, the dorsal fin base is shorter here than in C. ornatus.

There really isn't much difference in the dorsal profile of either species.

If I could, I would love to say yours looks like a hybrid of these two species, but I am sure it isn't. Patterning definitely goes in favor of C. sp. (C141), as you observed; the longitudinal and lateral band formations are clear in your cory. Your cory's dorsal fin spine is pale and stout.

I must say, your cory has many of the characteristics found in both species; after all these comparisons, I give it as my personal opinion that your cory is more likely to be C. sp. (C141).

[bekateen]

Thank you FerocactusLatispinus, and everyone else, for your feedback. Unless anybody has something else to offer, I will consider this C141.

Now that I've reached this point, I'm thinking, "Well that's just peachy!" Even if I know what it is, I also know three other things - 1) it's NOT agassizii (which I suspected all along), 2) the LFS where I bought it doesn't have any more (this one came mixed in with a shipment of other wild caught cats), so it's not like I can go back and buy anymore to try and breed them, and 3) I still don't have more agassizii to add to my current group, which I had hoped to get in an attempt to invigorate them to spawn (I've had the five agassizii for a year now and so far, they've done nothing but look pretty).

Sigh. Oh well, while I don't need to add more random fish to my tank (I don't want to overpopulate it, or disturb the community harmony that already exists for those spp. that are breeding), I guess I'll just enjoy this new addition for what it is, a fun-to-watch fish.

Thanks again.
Eric

[FerocactusLatispinus]

No problem!

That is really cool to hear that your cory came in randomly in a shipment; I got a Bunocephalus colombianus that way, and he/she's a real fun fish to watch interact with my other B. coracoideus! My banjo cat's situation was unique, but your find is really something! Congrats!

Wish you the best with raising your cats!

-Kaegen

[bekateen]

After looking at recently added photos of

Corydoras robustus

, I'm starting to rethink the identification of my mystery Cory as

C141

. Please compare the following photos to each other and to the photos of my Cory.

C. robustus:
http://www.planetcatfish.com/common/ima ... e_id=15596
http://www.planetcatfish.com/common/ima ... e_id=15669

C141
http://www.planetcatfish.com/common/ima ... ge_id=6717
http://www.planetcatfish.com/common/ima ... ge_id=9935

Also, notice in the photos ( 1, 2, and 3 ) of my Cory that its dorsal fin is oddly triangular, with a tall dorsal spine and a steeply sloping posterior edge, which then changes angle towards the bottom and goes down very slowly thereafter, as it extends posteriorly to its end. By contrast, my

Corydoras agassizii

possess dorsal fins with a more gentle, but gradually increasing descending angle, curving downward more as they slope posteriorly to their ends.

What are the specific differences between C. robustus and C141? As far as I can see, there's no locality info on C141 listed, so I can't go by that. The two traits standing out to me are (1) that full-grown C. robustus is a lot larger than C141 (3.5" SL vs. 2.4" SL), and (2) that male C. robustus have the huge white flare to the dorsal fin. My unknown doesn't have that huge projection, but its dorsal fin does have the distinctly steeper slope (as I described above; but note: The total height of the dorsal fins are not much different between my mystery Cory and my C. agassizii.), and currently my unknown is exactly the same size as my C. agassizii. But as such, it does bear a strong resemblance to small C. robustus.

Any thoughts?

[Jools]

AFAIK, the origin of C141 is unknown. Perhaps a German friend can dig out the article and see if there are any clues in it.

You also asked me via PM the undernoted, I will reply here so others can see what's going on.

Hi Jools,

Yesterday (using my phone) I noticed some new image updates for c049, the Cory with a white dorsal spine. My recollection was that this species had 3-4 total photos, one of which is still visible on the sp. description page, and 2-3 additional photos which bore little resemblance to the first; they struck me because they resembled a Cory of my own, which I believe to be c141. Since my phone's display is small, I had trouble studying the photos, so I came back today to reexamine the photos on a larger computer monitor... but now the additional photos are gone.

Is my memory just bad, or did you folks pull those photos down? Were they not of c049? If not, what is their i.d.? I'd really like to see them again and compare them to my Cory's photo.

At present I am going through a list of corrections Ian Fuller @coryman sent me. Bear in mind some of the pictures on this site are really old and the IDs made based on what we knew 5, 10, 15 or even more years ago. The pictures we had in

C049

were incorrect IDs and probably juvenile

Corydoras robustus

. One of the original four images was moved to that species, the other three removed (they were all of the same group of fishes). Hans has helpfully given me permission to use the original DATZ image for C049 which is what remains there.

Hope that makes sense.

One day, it may not be soon, I will re-start and finish my Corydoras identikit project. Don't hold your breath!

Jools

[bekateen]

Jools,

Thanks for the response. That explains what I saw (and didn't see later) regarding c049. I'm still left with the dilemma of how to discriminate c141 from C. robustus, and how my cat fits into that mess . Hopefully others can provide more insights.

Cheers,
Eric

[Karsten S.]

Hello Eric,

juvenile C. robustus are indeed similar. Once they are fully grown you can tell for sure.
However, I don't think that yours are C. robustus.

Cheers,

[bekateen]

juvenile C. robustus are indeed similar. Once they are fully grown you can tell for sure.
However, I don't think that yours are C. robustus.

Hi Karsten,
Thanks for the feedback. I would like to know what leads you in this direction - what are the fish's traits that you are cueing on.

That asked, even without additional comment I'm inclined to agree with you for a couple of reasons:
First, I've had this Cory for a couple of months now, and it hasn't grown at all, not one little bit. That leads me to believe that it is full grown; and at its current size, its right for C141 but not for C. robustus. Second, based on its pectoral fin shape, I suspect it's a male. If it were a male C. robustus, where is that dorsal fin flare? True, female C. robustus lack the dorsal fin flare, but the pectoral fins aren't right for a female. Besides, if it were female, wouldn't it be larger than the males, and thus (again) shouldn't this be a much larger fish? From these points, I believe that mine is a full grown male C141.

But here's part of my uncertainty: My fish has that dorsal fin with the odd curvature.

Photos of the dorsal fins of my unknown Cory and my agassizii, cropped and outlined

I realize that some of this might be an optical illusion, e.g., if its dorsal fin is slightly compressed in the photo. But even when fully extended, it has this same steep curvature. I've seen this in some other PC members' photos of different Corys (e.g, see Eric Bodrock's photo of his own C090). I imagine that this fin shape is a species specific trait. Looking at the PC photos of C141, some of the photos seem to depict a pointy dorsal fin, but many don't. Based on the photos of C141 and C. robustus, I would think this is more a C. robustus trait.

Dang, this is not easy.

[Jools]

The shape of dorsal fins is not a great characteristic for working out species, for starters it varies with maturity and between sexes. It's also very hard to get comparative photos from live fishes in water.

Jools

[bekateen]

The shape of dorsal fins is not a great characteristic for working out species, for starters it varies with maturity and between sexes. It's also very hard to get comparative photos from live fishes in water.

Double dang! This is now less easy.

[Borbi]

Hi,

AFAIK, the origin of C141 is unknown.

I just had a quick look at the original introduction of C141, and no location is provided in it.
It is presented as an occasional by-catch which is frequently erroneously ID'ed as C. ornatus.
C141 is supposed to have the markings of C. ornatus, but with a white first dorsal spine and it is a long snouted species.

I´m not much of a Corydoras-guy, but at least to my untrained eye, the snout of the fish in question is shorter than that of the fish introduced as C141.

Cheers,
Sandor

[bekateen]

I just had a quick look at the original introduction of C141, and no location is provided in it.
It is presented as an occasional by-catch which is frequently erroneously ID'ed as C. ornatus.
C141 is supposed to have the markings of C. ornatus, but with a white first dorsal spine and it is a long snouted species.

I´m not much of a Corydoras-guy, but at least to my untrained eye, the snout of the fish in question is shorter than that of the fish introduced as C141.

Hi Sandor,
Thank you for looking this up for me. Regarding the nose on my unknown Cory, you might right, but so far I have not been concerned with the snout being too short, for the following reason: the first photo at the top of this page isn't a good representation; although my Cory doesn't have a particularly long snout, it is entirely consistent with most of the PC photos of C141.

Cheers, Eric

[bekateen]

Fun update of how

C141

change with age. Here is the same fish, two years later. First two photos taken within days of purchase. The last photo taken today. Today the fish sat still for a clear picture, so you get a more accurate view of the shape/length of the snout.

Cheers, Eric

[Karsten S.]

Hi,

the cory is for sure no C. robustus, the holotype of C. ornatus also looks quite different.
I would still go for C 141, very nice one !

Cheers,

[bekateen]

Thanks, Kirsten! Yes, I agree, definitely not robustus. My only regrets are (1) the three I have now are very shy (along with my ambiacus), and (2) they haven't spawned again.

Cheers, Eric

[bekateen]

Another fun update: It's been nearly four years since I first bought the "agassizii" which were later ID'd as

Corydoras ambiacus

. Tonight I took a couple of photos of one of the males. He's over 65mm SL, getting close to 70 (he's big!). This fish is one of the specimens shown in an earlier post in this thread; I reproduced the same old photo here (he's the fish on the far right of a pair of photos showing three fish).

These are the first cats I've had long enough to raise them to max SL. I like these.

Cheers, Eric