Can we examine the photos of C. agassizii and C. ambiacus for confusion?

[bekateen]

Hi Jools,

In a recent forum thread on CorydorasWorld.com (http://www.corydorasworld.com/forum/?forum=9&post=245, if you are a member and have access to their forums), it came to my attention from Ian that

Corydoras agassizii

should have the dorsal fin black coloration extend all the way to the edge of the fin, but in

Corydoras ambiacus

the coloration does not. According to Ian, this is the single-most reliable trait for distinguishing these two species from one another. However, the photos of these species, as displayed on PC, seem to show a mix of this trait for both species.

Specifically, I'm looking at images #9 and #14 of ambiacus, which appear to have the agassizii-style dorsal coloration, and images #1, 2, 3, 4, 5, 8, 13, (and maybe #10 and #12, but these are far more "iffy") of agassizii, which seem to have the smaller spots of ambiacus.

I realize that some of this may be due to age/maturity, or individual variation, but is it possible for someone with authority and who is familiar with the sources of these photos to review the photos and make sure that they are properly assigned to the right species? Although I've singled out specific photos above, I would suggest that in the interest of thoroughness, all of the photos should be reviewed at once, not just the photos I mentioned above.

Thanks. Cheers,
Eric

[Jools]

Yes, we've not reviewed the entire genus since around 2006, so a good look at new material is not a bad idea at all. On these two it would be useful, I think, to have the original two descriptions and compare that to our current understanding expanded on above.

Jools

[Jools]

I will have some time tomorrow morning and hopefully tonight to look at this again.

Cheers

Jools

[bekateen]

Thanks, Jools.

Cheers, Eric

[Jools]

So, I agree. But there are some in there that have no black in the dorsal, and we will need a home for them too.

This is not helped by stressed fishes, I happen to know what is currently in slot 1 in C. agassizi had the full black first few dorsal fin rays before I chased it for a couple of minutes and dunked it in a photo tank.

Jools