Something is very wrong here bought 6 channa bleheri 3 days back
day one looks healthy
day two 2 died
day three 1 died and i start to notice something on the skins.
what can i do to keep them healthy
What temperature? It looks to me like bacterial infection
They look like they're in pretty bad shape, I'm not sure if they will make it. I would drop the water level to 3 inches so they can reach the surface without expending too much energy.
can you post a full tank pic?? snakeheads are very hardy fish generally and it seem they all have the issue in the same place. maybe they are burning on a light or something.
+1 let's see the full tank incase and What are your temps ?
I'm also thinking it's an infection brought on by high temps , Did the dead fish show similar symptoms? Is it something that is starting on the head then spreading or or does it cover the full back like that suddenly ?
Either way the treatment is the same but it's important to determine the cause and correct it.
For treatment as mentioned it'll help to lower the water levels,make sure the temps are correct and darken the tank so they feel secure. melifix/pimifix combo very effective on channa and is safe as a blanket treatment.
If it's physical damage they will recover. If it is an infection I hate to say it but at this stage it may be too late. I've seen this before in bleheri, it hits hard and fast very similar to the dreaded "eroding disease" that often kills Aurantimaculata.
VERY common with bleheri. I lost about 15 of them years ago due to same issue. The batch after I treated as soon as they hit my tank ( never showed signs of illness and did't want them to devolope). UNFORTUNATELY, nothing works at this stage of illness.