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Got some cories sold as nanus, but to me they lack the black bar at the base of the dorsal that the photos of nanus here show.

Gotta get them home, will post photos of them during acclimation, but until then I'm curious whats the difference between these species?

The fish.
Possibly bilineatus? They were sold as nanus but given how rare nanus are... lol

Those look like slightly stressed to me. is from a remote area that is not routinely collected from, and looks very different.

But ugh, ID'ing some of the elegans group can be challenging. It does look like one or more fish of yours might have a black blotch on the dorsal fin, so perhaps a very young should also be considered.

Cheers, Eric

bekateen wrote: ↑26 Oct 2020, 19:09 Those look like slightly stressed

Corydoras(ln5) elegans

to me.

Corydoras(ln5) nanus

is from a remote area that is not routinely collected from, and

Corydoras(ln5) bilineatus

looks very different.

But ugh, ID'ing some of the elegans group can be challenging. It does look like one or more fish of yours might have a black blotch on the dorsal fin, so perhaps a very young

Corydoras(ln5) napoensis

should also be considered.

Cheers, Eric

The whole group makes my head spin haha

Theyre small, all between 1.5-1.7" so far, but I dont factor size if I dont know the age, could be juveniles of a larger species for all I know based on size.

Was reading over on Scotcat too to see a variety of photos from there and here and there's so much variation.
But one thing that stood out is the yellow fins on the one with the black dorsal blotch.

The dorsal on the one is a big dark blotch, the other not as much.

Stressed yes because was just acclimating them to the new water as just got them home. I add them to a container and slowly add the tank water to the container over the course of 30-45 minutes to allow them to adapt reasonably. Then I pour them into a net and add them to their new tank, avoiding any water from the bag from going in my tanks. But acclimation is always gonna have paler fish, they take some time to colour fully. But in store they were very nice and dark.

Knowing how rare nanus are, I definitely doubt that identity haha, elegans or napoensis were my first thoughts, but some images of bilineatus were similar in some aspects too. What a complicated group of cories.

Napoensis can have yellow fins.

Alrighty so the blotchy ones with yellow fins are more likely napoensis. The other still good for elegans?

Wait till they color up and grow some, then reshare pics please.

Cheers, Eric

bekateen wrote: ↑27 Oct 2020, 13:34 Wait till they color up and grow some, then reshare pics please.

Cheers, Eric

Okay! Sounds good!

Now question, what age do they develop male or female colours? Do they change from fry colour to their respective coloring or do they all look female until maturity?

I dont know much about this group for that, I just saw them at the store and they were just really cute and that was the end of that lol

Hi,

you will never find C. nanus (Suriname) or C. bilineatus (Bolivia) in ordinary pet shops, if you ever should be so lucky to find them in specialised shops they should be very much more expensive than other Corydoras.
Both species are coming from countries from which there are no regular exports so there is basically no chance that they are imported accidentally. I know of one commercial import of C. nanus and none of C. bilineatus and in this case they did know that they are importing a very rare fish.
If those should be someday available from breeders I would expect that those will also know that these two species are rare and would rather first distribute them among other breeders and not give them to pet shops.

However, the colouration is definitely also not fitting to C. nanus.

Cheers,

Karsten S. wrote: ↑28 Oct 2020, 23:23 Hi,

you will never find C. nanus (Suriname) or C. bilineatus (Bolivia) in ordinary pet shops, if you ever should be so lucky to find them in specialised shops they should be very much more expensive than other Corydoras.
Both species are coming from countries from which there are no regular exports so there is basically no chance that they are imported accidentally. I know of one commercial import of C. nanus and none of C. bilineatus and in this case they did know that they are importing a very rare fish.
If those should be someday available from breeders I would expect that those will also know that these two species are rare and would rather first distribute them among other breeders and not give them to pet shops.

However, the colouration is definitely also not fitting to C. nanus.

Cheers,

I figured as much about the nanus, always a grain of salt. I dont trust their identifications. They labeled their pandas as wotroi, enough said haha. Ah I bought some expensive pandas that day, but hey they were cute and not many shops in my area even sells pandas anymore.

But I digress.

I figured more likely in the elegans type as they all look so close to one another.

Couple more photos

bekateen wrote: ↑27 Oct 2020, 13:34 Wait till they color up and grow some, then reshare pics please.

Cheers, Eric

Added some newer photos, stronger colour. See above comment too theres more there

Well if napoensis is the one that has the black blotch in the dorsal, im thinking all mine are napoensis as now fully colored up, they all have the dark thick blotch.

Except for possibly the top photo in your last post, I don't see any C. napoensis there.

This group (lineage 5) is a tough group to ID sometimes

Cheers, Eric

bekateen wrote: ↑31 Oct 2020, 19:15 Except for possibly the top photo in your last post, I don't see any C. napoensis there.

This group (lineage 5) is a tough group to ID sometimes

Cheers, Eric

What are some good clues to look for between all of the species? And which are the most common to come across?

These guys are stinking cute. I love how dainty their faces are compared to other cories. Its like they tried to be pygmies lol

MissNoodle wrote: ↑21 Nov 2020, 09:04Its like they tried to be pygmies lol

There's some truth in that. Fishes, generally, evolve into smaller species, and when you look at the faces of you can begin to see how they split out into different lineages. The one that this is most obvious in (for me) is it's halfway between. It used to be considered a subspecies of C. elegans BTW.

Jools

Fish A, lacks tan stripe on head and back, has white/grey fins Fish B, has tan stripe on head and back, slightly yellowed fins.
Same species (different genders)?

Or 2 different species?

Would say fish A does look male and fish B, female.

Jools

Jools wrote: ↑31 Dec 2020, 08:18 Would say fish A does look male and fish B, female.

Jools

Both elegans? Male elegans are more checker patterned, yes? Or is there even variation in that?

Any plausibility these could be CW064?
https://www.planetcatfish.com/common/sp ... species_id

Looking at a German site, the images posted that mr fuller shared look super close to the pattern and shape to the ones I have.
Won't post the link unless asked though as I dont know if posting other sources is against the rules or not.

I will also say both of these fish have nothing to do with one another. They ignore each other in favour of hanging around other species.

Fish A Fish B

They look like regular, variable, C. elegans to me. The middle one is a great pic!

Jools

Awesome, then knowing for sure what they are, then I can look for more
Thank you!