Fish look dusty!

[melypr1985]

Out of curiosity why does ich kill some fish but others live? Is it because the immune system is lowered so they are susceptible to other diseases/general weakness and that ich can attach behind the gills lowering oxygen supply?

I did come across this when I was looking into marine fish diseases, I've not tried it because so far I've not had to deal with ich. It's about hydrogen peroxide bath.

Ick can certainly be deadly, but most -otherwise healthy- fish will be able to build up a resistance to it and live for a while with the parasite in the tank. There are several types of fish that just can not handle ick on their own due to their lack of defenses (thin slime coat), while others are able to withstand it seemingly with no problems at all. Those fish typically have a very thick slime coat which affords them lots of protection from ick and other parasites.

Fish who die from ick probably die from one of two reasons: Suffocation from the parasite being in the gills and fluid building up in the gills to try to fight it off. Infection: Ick burrows under the outer layer of skin to feed off of the fish. The white spots you see are the slime coat, again, attacking the parasite from the outside. Most of the time, ick stays in the gills, but when the outbreak is bad enough you'll see it on the body. These points where the parasite has burrowed into the skin create an opening for bacteria. The parasite feeding off of the fish creates a lowered immune system and can allow for the bacteria to take hold instead of being fought off by the fish's body.

There are many reasons a fish dies from ick, while others don't but these two are the main ones.

Peroxide is being looked at for a dip to treat velvet, but not ick. Being that ick is protected inside the fish's skin (burrowed like it is) I highly doubt peroxide would have much effect on it while being attached to the fish..... at least while still being safe for that fish to survive in. I hope that helps

 

[Brew12]

Ick can certainly be deadly, but most -otherwise healthy- fish will be able to build up a resistance to it and live for a while with the parasite in the tank. There are several types of fish that just can not handle ick on their own due to their lack of defenses (thin slime coat), while others are able to withstand it seemingly with no problems at all. Those fish typically have a very thick slime coat which affords them lots of protection from ick and other parasites.

Fish who die from ick probably die from one of two reasons: Suffocation from the parasite being in the gills and fluid building up in the gills to try to fight it off. Infection: Ick burrows under the outer layer of skin to feed off of the fish. The white spots you see are the slime coat, again, attacking the parasite from the outside. Most of the time, ick stays in the gills, but when the outbreak is bad enough you'll see it on the body. These points where the parasite has burrowed into the skin create an opening for bacteria. The parasite feeding off of the fish creates a lowered immune system and can allow for the bacteria to take hold instead of being fought off by the fish's body.

There are many reasons a fish dies from ick, while others don't but these two are the main ones.

Peroxide is being looked at for a dip to treat velvet, but not ick. Being that ick is protected inside the fish's skin (burrowed like it is) I highly doubt peroxide would have much effect on it while being attached to the fish..... at least while still being safe for that fish to survive in. I hope that helps

I would only add to this that not all fish of the same species are exactly the same. Just like the flu can kill some people and others shrug it off, fish are no different. Some just have better immune systems and are in healthier shape when they are subjected to something like ich.