Corydoras Species

[Mattyzz]

Hello there! Sorry if this has been answered before but I want clarification that between Julii, Trilineatus, and Leopardus are three different species. My own research points to:

1: Julii have finer spots on their head, rounded face?

2: Trilineatus have connected patterning along side the the three stripes that they have, from my own fish tank they have a rounded face as their barbels point more straight down.

3: Leopardus maybe have some connected patterning but their face comes to a point which is signified by the longer face and their barbels point more at an angle to the ground.

I'm trying to figure it out because I did buy 6 corys about a month ago and had a hunch that they are not Trilineatus but actually Leopardus. Which if they are would make more sense why my 2 Trilineatus(?) don't really follow them around as much. It's hard to tell because they are comfortable meandering about the tank most of the time.

Here are the two I believe to be Trilineatus as I've had them the longest. (8 Months)

 

Now here are some of the 6 I got a month ago.

 

Sorry about the clutter on the supposed Leopardus corys I had just dropped food in for them. I'm seeing a longer face?

Are there any long term effects of 6 Leopardus and 2 Trilineatus?

[CorydorasEthan]

On 6/13/2021 at 4:36 PM, Mattyzz said:

Hello there! Sorry if this has been answered before but I want clarification that between Julii, Trilineatus, and Leopardus are three different species. My own research points to:

1: Julii have finer spots on their head, rounded face?

2: Trilineatus have connected patterning along side the the three stripes that they have, from my own fish tank they have a rounded face as their barbels point more straight down.

3: Leopardus maybe have some connected patterning but their face comes to a point which is signified by the longer face and their barbels point more at an angle to the ground.

I'm trying to figure it out because I did buy 6 corys about a month ago and had a hunch that they are not Trilineatus but actually Leopardus. Which if they are would make more sense why my 2 Trilineatus(?) don't really follow them around as much. It's hard to tell because they are comfortable meandering about the tank most of the time.

Here are the two I believe to be Trilineatus as I've had them the longest. (8 Months)

 

Now here are some of the 6 I got a month ago.

 

Sorry about the clutter on the supposed Leopardus corys I had just dropped food in for them. I'm seeing a longer face?

Are there any long term effects of 6 Leopardus and 2 Trilineatus?

Hey there! Yep you got the facts right in your key identification points! However, I believe that not just two of the cories are C. trilineatus, but all of them. They all have the trademark trilineatus patterning on their body - reticulated pattern of bold black markings on the head with a distinctive black line going down the center of the body. The cory that you showed in the second picture doesn't seem to be full grown to me, so it might develop its full patterning sometime in the future.

Additionally, all of their snouts are somewhat rounded. The reason why some have longer snouts is purely genetic - I think it just varies depending on the individual. For example, my two albino cories are both definitely C. aeneus, yet both their snouts have different lengths.

Another thing is that Corydoras barbels are flexible. They sometimes point down and sometimes straight, depending on what the fish is doing. Of course, it does vary between different species, and it is true that with longer snouted cories, the downward facing barbels are more pronouced.

However, your cories seem to have similar barbels and snout shapes to other short-snouted species (like C. paleatus, C. sterbai, C. habrosus, etc.), suggesting they are indeed C. trilineatus, which is also a member of the short-snouted group.

Here is an article on the different types of Corydoras-type catfish. It is really interesting in understanding of behavior and identification. I highly recommend it. https://corydoras.zone/fish/corys/corydoradinae-corydoras-lineages/

Example of C. paleatus (close relative of C. trilineatus) with a similar snout shape.

So with this I can conclude that your cories are all C. trilineatus. The reason the two may not follow the others around is because they are older and don't play as much with youngsters (they look bigger more mature from the pictures). Also, from what I can tell, at least one of them is a female who might drop eggs soon, so it might be the smaller males following her instead!

Here is an updated identification list in case you need it in the future:

1. C. julii have a more dotted pattern around their full body, with sparser markers, giving them the appearance of having a slightly lighter coloration overall. Their lateral line is not solid, but rather a series of black marks. Round snout.
2. C. trilineatus have a reticulated pattern of black marks around their head. Thick dark line going down the middle of the body (lateral line). Many vertical strips along the back and flanks, giving the impression that they have three lines going horizontally down the body. Round snout.
3. C. leopardus has very fine markings along the head, and reticulated pattern on the upper half of the body. Slightly golden coloration. Very pointy snout.

Wow it was fun and refreshing answering this Corydoras identification post. Sorry for the semi-long read. Anyways, I hope this helps, and good luck!

[Mattyzz]

@CorydorasEthanThank you so much for the detailed post! I love all of it. This will definitely come in handy for the future and I will see what the 6 younger ones turn out to be in the coming months. Seems like I got to used to my adult-sized corydoras and forgot what they were like before they uhhh... chonked up.

[Colu]

Great book is Ian.m fuller  identifying corydoradinae catfish  great identification guide

Edited June 13, 2021 by Colu