Not sure why one side of gills is red.

[AllyzKatt]

Hello, I bought fish from Dan's and I have never been disappointed by his care and quality of fish. I bought a batch of neon tetras and after acclimating them a few days later, I noticed one had red gills but only one side. I put it in a hospital tank and did a regiment of paracleanse, maracyn, and ich-x. For a whole week. But the red wound-like thing in its gills look the same. Not worse nor better. I am not sure what to do next. Please help.

[TOtrees]

I don't have the why, but what you're seeing looks like a missing or shortened gill cover, aka operculum. The gills should be covered by the gill cover, which I assume is the case on the fish's other side. Gills are always (should always be) be bright red. The reason we never see them is the plate-like covering that grows back from the face over the gills. This plate or operculum is what bellows in and out when fish appear to be breathing heavily, because it helps to increase water flow over the gills, therefore gets more oxygen to the gills and from there into the blood. 

[AllyzKatt]

On 4/25/2024 at 10:39 AM, TOtrees said:

I don't have the why, but what you're seeing looks like a missing or shortened gill cover, aka operculum. The gills should be covered by the gill cover, which I assume is the case on the fish's other side. Gills are always (should always be) be bright red. The reason we never see them is the plate-like covering that grows back from the face over the gills. This plate or operculum is what bellows in and out when fish appear to be breathing heavily, because it helps to increase water flow over the gills, therefore gets more oxygen to the gills and from there into the blood. 

Thank you so much, that makes sense. So, would it be okay to place him back in my 20 gallon with the other neons? The other side is fine and looks normal. Picture attached.

[MattyM]

If the fish is behaving normally and eating (he may be a bit stressed), I think you should be OK to acclimate him back to the original tank. 

[AllyzKatt]

On 4/25/2024 at 1:44 PM, MattyM said:

If the fish is behaving normally and eating (he may be a bit stressed), I think you should be OK to acclimate him back to the original tank. 

Thank you, I will do that today because he is eating fine and acts like any normal fish. Thanks again!