Cory I.D. questions

housewren · Post by **housewren** » 30 Dec 2004, 16:42

I have three different species of catfish, each sold as C. punctatus, and none of which are the true punctatus. I am having a hard time identifying them using the catalog, because there are several similar species, and I don't know what subtle or not so subtle characteristics differentiate them.

For two of my species, I think I have narrowed them down to one of two species. How does one distinguish between these species pairs--visual, fin ray counts, behavioral characteristics, etc.)

1. C. napoensis and C. bilineatus

2. C. melanistius and C. leucomelas (the ones I have spend a considerable amount of time swimming in midwater compared to my other cories. Is a major different that leucomelas has spots between the mask and the dorsal black mark, and melanistius does not? There was only one picture of the latter, so I am not sure if that is just individual variation, or a good character. Also, I noticed that the individual pictured as melanistius doesn't appear to have spots on the tail.

The third species -- it is spotted, with some of the spots arranged in rows, has a faded mask (not a dense black)that doen't extend below the eyes , a plain face (not spotted on the snout), a dark blotch (not a dense black) at the base of the dorsal (does not noticeably extend into the dorsal, and a spotted tail. I am leaning towards C. agassizii (the shape is more like that than C. ambiacus), but the dark spots are faded and there is no black on the dorsal. Are there other species I should consider?

Is there a source where I can go to find the differentiating characteristics?

Thanks for the help.

Cheri

Post by **Coryman** » 30 Dec 2004, 20:07

All known described species of Corydoradinae can be found here including the C numbers 1 -136. Not every species is covered with a picture, but i am working on it.http://www.corycats.com/
To help here are pictures of the species you are having problems with, I hope they help.

C. agassizi

C. ambiacus

C. bilineatus

C. napoensis

C. melanistius

C. leucomelas

Ian

housewren · Post by **housewren** » 31 Dec 2004, 06:18

Thanks Ian for those pictures. It was nice to have them "side-by-side" for comparisn. I have studied those and the one's in the catelog, however,and am not sure what to look for to differentiate some of them.

I managed to get some pictures. They're not the greatest, but hopefully they will do.

Here is the first species: looking at your pictures, the only difference I clearly see is that the lines on "napoensis"
start farther back. On mine, however, it looks somewhat in between. What should I be looking for?

The fish on the left has the lower line starting a ways back, and the fish in the middle has the upper black line broken up a bit.

I am leaning towards "bilineatus"

For the second species, I think it it "leucomelas" because it has the barred tail, whereas "melanistius" doesn't.

For the third species, I am still at a loss. It doesn't seem to be like either of them. On two of the three that I have there is no black spot on the dorsal, but on one of them, the outer part of the second and third rays is black. The shape is not like that of "ambiacus".

Here is another picture, so you can see the profile.

What do I really have?

Thanks,

Cheryl

Post by **Coryman** » 31 Dec 2004, 17:09

C. bilineatus
C. leucomelas
C. agassizii

Would be my selection.

Ian

housewren · Post by **housewren** » 09 Jan 2005, 20:38

Thanks for the I.D.'s It's nice to have proper names to pin on them.

In a search on the Internet, I have seen references to breeding C. leucomelas and C. bilineatus, but have come up blank with C. agassizii. Has the latter been bred in the aquarium?

Cheryl

Post by **Coryman** » 10 Jan 2005, 01:47

C. agassizii as far as I am aware has not been bred in captivity.

Ian