C. Aeneus or lookalike?

[MissNoodle]

Probably Aeneus but figured id ask anyway.

One has yellow fins rather than clear.
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[bekateen]

Most corys sold in the USA (and I'd imagine in Canada) as bronze corys

Corydoras aeneus

are farmed. As such they are some kind of aeneus-like cory, but are probably not aeneus as it was originally described (a species native to the island of Trinidad, separated from the mainland). There are many aeneus-like corys throughout South America. Some have other scientific names (like

Corydoras schultzei

) and others have C- and CW- numbers. It's unknown whether these all should get unique scientific names or if any should be considered real aeneus since they afte so widespread across South America
(and thus unlikely to be genetically the same) and yet nobody to my knowledge has studied them to figure it out.

In the meantime, unless you specifically know you're buying wild- caught fish from Trinidad, you're probably getting farmed fish. And if you don't know how the fish farm was established and how careful that farm was to ensure the purity of their parent breeding stock, you are left wondering if the farmed fish might be an unintentional hybrid of aeneus-like fish collected from different sources.

Besides all that, it's normal to expect slight color variations between individuals, especially juveniles like yours, even within a species.

Cheers, Eric

[MissNoodle]

Most corys sold in the USA (and I'd imagine in Canada) as bronze corys

Corydoras aeneus

are farmed. As such they are some kind of aeneus-like cory, but are probably not aeneus as it was originally described (a species native to the island of Trinidad, separated from the mainland). There are many aeneus-like corys throughout South America. Some have other scientific names (like

Corydoras schultzei

) and others have C- and CW- numbers. It's unknown whether these all should get unique scientific names or if any should be considered real aeneus since they afte so widespread across South America
(and thus unlikely to be genetically the same) and yet nobody to my knowledge has studied them to figure it out.

In the meantime, unless you specifically know you're buying wild- caught fish from Trinidad, you're probably getting farmed fish. And if you don't know how the fish farm was established and how careful that farm was to ensure the purity of their parent breeding stock, you are left wondering if the farmed fish might be an unintentional hybrid of aeneus-like fish collected from different sources.

Besides all that, it's normal to expect slight color variations between individuals, especially juveniles like yours, even within a species.

Cheers, Eric

Itd be hard to say exactly if farmed or wild caught. I know their trilineatus are wild caught. Ive gotten both weitzmani and agassizii by catches in with them.

And their paleatus are very iridescent, as per this site's comment that wild caught tend to be this way, theres a chance their paleatus are too.

So these ones are probably from the same source as this locality has limited fish stores, but can't say if wild caught or farmed.

I do know they dont really stick together, kinda go off with the other cories more than with each other.

[MissNoodle]

So updating... theyve coloured up. One is pale, one is grey, and one is a lovely bundle of colour.

These two above are the same fish, nice colouring.

This one is super small so no clue. Im still nursing this tiny guy to good health.

[bekateen]

The failure to grow may mean there's something intrinsically wrong with the small individual. That would also explain its lack of color. I don't mean to suggest it's diseased, but rather perhaps a birth defect or genetic defect or hormone imbalance - who knows what - is preventing it from taking off and growing robustly. You could try raising it separately. Sometimes being with bigger corys can stunt the growth of smaller individuals.

Good luck, and happy new year.

Cheers, Eric

[MissNoodle]

The failure to grow may mean there's something intrinsically wrong with the small individual. That would also explain its lack of color. I don't mean to suggest it's diseased, but rather perhaps a birth defect or genetic defect or hormone imbalance - who knows what - is preventing it from taking off and growing robustly. You could try raising it separately. Sometimes being with bigger corys can stunt the growth of smaller individuals.

Good luck, and happy new year.

Cheers, Eric

Its been a little over a week with this guy, so i dont expect a dramatic surge of growth yet. But im watching him. He was really really thin when i took him in. Sunken belly and withered away. Hes got a belly now and hes filling in more, just tiny. Ive done one treatment for parasites and the skin flukes he had have cleared up and hes looking clear of internal parasites too, so thats good. But i could tentatively allow him into another tank to grow him out if necessary.

This is him beside my largest, my female paleatus.

And nibbling my hand with one of the other "aeneus"

Theyre not shy at all, curious and love to come check me out when im doing tank maintenance.