Kenneth Carl

The important thing with panda corydoras (or any species for that matter) is buying from reputable breeders. They are often mass-produced and are considered overbred, so their genetics and their health are often questionable. Good breeders will have a diverse gene pool within their breeding stock, they source multiple groups of fish from multiple sources to increase the chance of unrelated fish breeding with each other. Bonus points if their breeding stock consists of F1 (or fish recently bred from wild-caught fish) or some thoroughly quarantined wild fish. I found some breeders on Vivvy, aqua bid, and get gills. Don't be afraid to ask these breeders questions about their breeding stock, they should be more than happy to provide you with information.

South America has a diverse cast of biotopes, there are multiple species that can be kept unheated with relative ease, with some species handling 60F just fine.. Blanket statements like "cichlids like their water warm so like 80-82" should be taken with a grain of salt, this is more applicable to tropical species in the Amazon and other warmer territories. But species found in argentina, brazil, and other semi-temperate zones can be kept without a heater if your house doesn't get super duper cold (below 60).

Paleatus come from Uruguay and many other cool parts of South America. Some of those areas can dip into the 50s, so you are well within range of keeping them unheated. You can even do aeneus, mine are doing well at 62F this winter. Just make sure to feed them a little less during the winter. They aren’t digesting food as fast.!

Looks like melanoma, something that ember tetras seem prone too. This is likely the result of too much inbreeding, whoever is breeding these, I would suggest finding wild specimens and adding them to your breeding stock. Clearly this is becoming more common.

If you are going to breed ember tetras, please purchase from multiple sources to ensure some genetic diversity.. You have to think about the problems of inbreeding that are plaguing fish today, and how you can improve the gene pool when you breed a species in captivity. The ember tetras I got from LiveAquaria were of poor quality, they were hardy but they were prone to a type of melanoma cancer. Black lumps would grow inside them and spread, the fish then develops popeye, and dies shortly after. Most of them died after the 8 month mark, my only survivors are only a year old under my care. This could have been avoided if they were outcrossed to unrelated individuals.