Cory quiz!

[Shivjindal]

Hi All

I bought 4 corydoras a while back and 3 look the same and one slightly different, the pic below shows one of the 3 and the one slightly different. They were bought as 'Corydoras nanus'. Are the two in the pic the same species? If you pop the pic out you can see the fish on the right has a much stronger dark line along its body although its face is reminiscent of the fish on the left, male and female maybe?...



I then recently spotted a lone catfish in my local fish shop which I felt sorry for being on its own and thought would go nice with the four cory's I have and bought it as 'Corydoras jullii'. I then saw a photo in my fish bible (Baensch Aquarium Atlas) that looked exactly the same as the fish I bought but was 'Corydoras trilineatus' (three line armoured catfish) and not julii but there is no photo of julii so wondering if i have C. trilineatus or julii? Photo as below....



They are all getting along great by the way

Cheers, Ade

[fr499y]

My knowledge of Corys isn’t that great so I’m no help. @Stephen, @Martinspuddle, @plankton might well know

[Stephen]

The cory in the foreground of the top picture looks like Corydoras nanus, the one in the background is likely a Corydoras napoensis.

The bottom picture looks like Corydoras trilineatus which are often mis-labelled as Corydoras jullii.

All the best

[plankton]

The top two may both be c.napoensis, there are some variations and the more background one is smaller and probably younger, although I'm not saying @Stephen is wrong.
The bottom one is definitely c. trilineatus.

[Martinspuddle]

The one the right could be Corydoras Elegans, the rest I agree with @Stephen

[Stephen]

The one the right could be Corydoras Elegans, the rest I agree with @Stephen

@Martinspuddle
It does look similar to Corydoras elegans but does not have the markings on the dorsal fin that Corydoras elegans has.

Corydoras nanus


Corydoras elegans

The top two may both be c.napoensis, there are some variations and the more background one is smaller and probably younger, although I'm not saying @Stephen is wrong.
The bottom one is definitely c. trilineatus.

@plankton
The one in the foreground is not a Corydoras napoensis as it does not have the dorsal fin marking.
I believe it is a Corydoras nanus (as bought).
The one in the background does have the markings of Corydoras napoensis and the dorsal fin marking too.

Corydoras napoensis


The markings are more visible when the original image is enlarged (as below).

[Martinspuddle]

@Martinspuddle
It does look similar to Corydoras elegans but does not have the markings on the dorsal fin that Corydoras elegans has.

Oh I agree with you @Stephen but I questioned it because if you enlarge the picture fully, you can see there are faint markings on this fishes dorsal fin.

[Shivjindal]

Thats brilliant everyone - thanks for your replies and very helpful. So it looks like i have one C. nanus, 3 C. napoensis and 1 C. trilineatus, interesting stuff. One last question, how do you tell the difference between C julli and C. trilineatus?

[Gingerlove05]

I believe Julii are spotted where as trilineatus have reticulated markings

[Stephen]

One last question, how do you tell the difference between C julli and C. trilineatus?

(click image to enlage)