Elevated stress levels are at the root of most health problems in fish. Short-term stress will cause an increase in heart rate, blood pressure, and respiration. Fish can only maintain these altered states for a short period of time and then they will adapt or the stress will become chronic. Chronic stress can have a negative effect on growth, reproduction, digestion and will also compromise the immune system ultimately allowing parasites, bacteria, and fungi to infect a stressed fish and cause disease and death.
Most common causes of stress: poor water quality, low oxygen levels, inadequate hiding places, overstocking, improper nutrition and disturbances. While it is impossible to eliminate all stress, we do have the ability to limit or prevent many of the causes. Provide the highest quality water, nutrition and suitable tank environment. Introduce new fish carefully and always use a quarantine or treatment tank when necessary.