Disease

You soon learn to intuitively see if the fish has become ill, although there are large individual differences from fish to fish. Sit completely still and watch carefully what the fish do. Get to know the animals and you'll soon get a feel for whether they're doing well or not.

The following lists can hopefully provide a clue.

Signs of good health

• Natural elegance.
• Good appetite.
• Curiosity.
• Clear colors.
• Alternates between being active and resting (some are very active).
• Shows aggression and is territorial (take into account individual differences).
• Reacts or flinches at sudden movements and sounds.

Signs of poor health

• Jerky, strained or otherwise strange movements.
• Balance loss.
• Passivity at the water surface or on the bottom.
• Lacks appetite or regurgitates food.
• Bad skin/fins.
• Lethargy; does not react to sudden movements and sounds.

Other signs of poor welfare

• Hiding between plants or at the bottom.
• Pale colors.
• Panics or becomes very frightened by sudden movements and sounds.
• Extreme aggression.
• Longitudinal stripes (indicates submissiveness).

If you find that your fish is sick, you should look in an aquarium book or contact the pet store or similar, to find out what is wrong with it. You can often save a fish's life if you give it the right treatment at the right time.