fish scratching itself on the rock????

[joniterrett]

hi
i have just brought a mexican rock wrasse. it has just started rubbing itself on the rocks as it swims is this normal???

[chopsuey]

If it continues to do this it is not normal. Usually you will see this happen when your fish is sick. It is trying to scrap the parasite from it scales by scratching against the rocks. Move the fish to a quarantine tank and medicate him. Or get a cleaner shrimp in your tank before the parasite kills your new fish and spreads to the rest of the fish in your tank.

[Travis L. Stevens]

No, this is not normal. This behavior is called "Flashing". This is when the fish flashes against the rocks. It does this in an attempt to dislodge any parasites on the skin. But sometimes, they will do this when there are internal problems. Most often when this happens in the marine hobby, it is usually because of Marine Ich (Cryptocaryon irritans). It should be placed in quarinitine so it cannot infect other fish. While in quarintine, make sure that you choose a method of dealing with the problem and do so in a seperate hospital tank. This way your treatments stay confined.

[ScoobyDuu24]

So how do you Quarantine a larger fish such as a Naso? I don't have a tank big enough to QT him.

[Travis L. Stevens]

This is where you would encounter a problem back in the planning stages of your aquarium ;) If something was to happen and you needed to treat with copper, you couldn't do it in the display because it will kill all invertebrates and corals. You could always get a kiddie pool, a large trash can, large tubberware/rubbermaid bins, or some horse troughs for huge fish. You can pick up a 300g trough for about $300 ;)

[boxfishpooalot]

osmosis-is the way fish balance ions outside of their body. Salt is constantly being secreted by salwater fish. The fish has to remain osmotically balanced, or they become dehydrated from water loss.

Living creatures have many types of salts/ions and other substances dissolved in their bodily fluids. If their concentration is different from their concentration in the surrounding fluid, the organisms has to maintain or withhold the difference for its normal function.

Changing the salinity rapidly puts osmotic stress on the fish, allowing disease to affect them.

Watch your salt content, make sure your not dumping in fresh water to replace evaporated water. That is very stressfull to fish. IT has to be added slowly.