My Freshwater Shark Keeps Simming In Circles

Question
Can you explain to me the weird behavior with my shark. I'm not sure what type of shark it is. But I have noticed that sometimes my shark will spend hours swimming in circles from the top of the tank to the bottom. My shark will continue to do this for hours maybe even days. Is there something that should be done when this happens. Is it a sign that my shark is hungry. Is the water temp not set right. Please tell me what this is.

Answer
Hi Sissy;

Without any information about your tank and more about the fish, I really can't help.

Is the tank large enough for him? What size is it?
How big is the shark?
How long have you had him?
How long has the tank been set up?
What kinds of decorations does it have?
Are the other inhabitants bothering him? What kind are they?
What do you feed him? Does he eat readily?
What is the water temperature?
How often do you change water?
Let me know anything else you think will give me more clues.....

At Your Service;
Chris Robbins