A

[NYG]

A

[Silurus]

The last one is

Corydoras blochi

.

[bekateen]

Yes, the one on the right in the first photo (I'll call this fish #2) is indeed

Corydoras trilineatus

.

The last one is

Corydoras blochi

.

Silurus, I hesitate to question your judgment, but IMHO the snout on the third fish (in the second photo) doesn't look long enough for the fish to be blochi. Perhaps it's just the camera angle, but I'd be inclined to look for a cory with a medium-length snout.

What about

Corydoras delphax

,

Corydoras ambiacus

(see this photo),

Corydoras brevirostris

, or

Corydoras melanistius

(see this photo)? Most of the images of melanistius have snouts which are shorter than on the fish of the OP, but the image I linked has a medium length snout, similar to what is seen on the fish in the OP's photo. Also, what about C075? (sorry but there's no photo of C075 here, so you'll have to look at Corydorasworld.com). Actually, I like C075 for the third fish better than I like melanistius because of the shape of the snout, but the C075 photos at Corydorasworld.com don't show black extending up onto the dorsal fin as much as in the OP's photo.

As for the first fish, it looks somewhat immature and I'm having a difficult time judging. I'd like to hope that the first fish is just a less mature version of the third fish, but I doubt it's that simple. But if I had to pick something else, I think I'd pick

C021

, C034 (again no photo here), or

C054

... To be honest, I have no idea about that fish. It looks like everything and nothing, all at the same time. LOL

Cheers, Eric

[NYG]

A

[Karsten S.]

Hello Eric,

you are absolutely right, this definitely no C. blochi.
I think C. delphax is a good call. This is certainly not the most frequent species in stores but also not impossible to find.

The other one is difficult to tell, it looks very/too pale. I would be interesting to see it with colours .
I looks to be related to C. ambiacus or C. agassizii, there are lots of similar species/forms.

Cheers,

[bekateen]

The other one is difficult to tell, it looks very/too pale. I would be interesting to see it with colours .
I looks to be related to C. ambiacus or C. agassizii, there are lots of similar species/forms.

I was also thinking that this is a very ambiguous fish. It's interesting that you think this fish could be ambiacus or agassizii, because I was considering ambiacus for the third fish, and agassizii is very similar, so that would be a good choice too (and the snout is about the right length for both of those). Maybe, if the OP is lucky, this fish is just a less mature or washed out individual of the same species as the third. I have not seen subadults of these spp. to know how similar/different they look. Karsten, do you have an idea on this?

I'm guessing it is safe to assume that I will not be able to find any of the corys in a store ever again, so should I just focus on increasing the amount Corydoras trilineatus in the tank?

Hi NYG,

Yes, that would be my expectation too. What surprises me at all is that you got all three of these from Petco in the first place. It's been my experience that the corys at Petcos in my region are all captive bred and thus when a store gets trilineatus, they get only trilineatus (not a mix of trilineatus and other spp.); I've never seen oddballs at my local Petco or PetSMART (of course, the intermixing occurs all the time at LFSs, where they are more likely to get wild-caught fish of mixed and questionable origins).

I suppose there is always a slight chance that if your particular store is getting its fish from the same supplier each week/month (which it probably is), then you have a minor chance that these oddballs will show up again. Just keep your eyes open; now that you know what these guys look like, you can study new arrivals for slight differences.

Cheers, Eric

[rmc]

In my opinion the pale one is C.ambiacus, in the same (top post) picture the other fish is C.trilineatus, and the fish in the 2nd picture (top post) is C.delphax. These are all fish that I have seen at Petco and they (all Petcos) are supplied by the same national fish supplier according to the Fish area Manager at the Petco near me.