My black shark is getting spots on its body and is acting

Question
Hello,
I have had a small black shark (catfish) for over 2 years, and a couple days ago, it started acting crazy.  It is a usally quiet fish that likes to hide in the tank.  Recently, it started swimming around furiously in the tank (going round and round in circles).  When I cleaned the tank the other day, I noticed that a small piece of it's tail had come off.  I'm not sure if this is from it swimming around like crazy, because when he does this, he is also ramming into the plants and rocks in the tank.  Just today, I'm starting to see white spots on his body.  Can you tell me what is going on.  I'm a little worried.  I've had this fish for awhile and I don't want to lose it...Thanks!
P.S.  Should I remove him for the other fish in the tank?  

Answer
Dear Monica,
It certainly sounds like your Black shark has ICK or white spot parasites affecting him. This common parasitic infection always appears as fine white dots on the fishes body as if that fish were sprinkled with salt. This would also explain the odd behavior he has been exhibiting of dashing around the aquarium and even into things. The parasites could be bothering him and making him itch-we're not really sure how the fish feels when infected with ICK. But I'm sure it makes them feel very uncomfortable.
Treatment should begin right away. White spot is VERY contagious and sometimes it's best if the whole aquarium (all the occupants) are treated as it's highly possible they all can come down with it. The heat/salt method of treatment should work out fine for you. Medications are so hard on fish and they also can destroy your beneficial bacterial colonies which would result in rising ammonia and nitrite levels.
After doing a 50% water change-
Slowly raise your aquarium's temperature to 82-84F will really help in treating many fish diseases. Illnesses like Ick can be eradicated by such treatment. Raise the temperature slowly though. One or two degrees every hour or so.
And with salt use Aquarium salt at -1tablespoon every 5gals-
Remember to add the salt slowly to watch for any reactions on the fishes part. Most fish tolerate salt just fine but others become stressed by it. Observation is the key.
*This tends to be the better and less stressful alternative to medication use. This treatment should continue for up to 2-3 weeks.

~Also, do 50% water changes every day to every other day. This really helps relieve stress on the fish. Add salt for the amount of replacement water you took out only! Just to note- Salt does not evaporate. Always remember with your replacement water to always dechlorinate it with a good water conditioner and be certain to equalize the temperature of the replacement water as well. A tad bit warmer is fine but cooler water is risky.

I'm really sorry to hear your shark has white spot. Fortunately this is probably the easiest of fish illnesses to treat and most fish make it through just fine. Feel free to write if you have anymore concerns!!

Best wishes and Best of luck!
Karen~