Stress in Aquaria: Acute Stress and Osmorespiratory Compromise

Acute Stress in Aquaria
- Netting, Shipping, Tankmates, Water Quality, Nutrition, Tank Space and Turning Radius can all play a factor in what they call 'acute stress.' Acute Stress is considered a small amount of stress over a long period of time, or minor stresses that are a regular occurrence. Acute Stress can suppress the immune system in fish. All of these issues that I have listed in this thread contribute to 'acute stress' in Stingrays. Many people have deemed stingrays a delicate animal, but more often than not many of these 'acute stress' factors play a major roll. The more of these stresses you eliminate, the more successful you will be.

Osmorespiratory Compromise:

1. Stress hormones released into the bloodstream cause an increase in heart-rate and an increase in blood flow to the gills.
2. The increased blood flow to the gills results in the dilation of blood vessels in the gills.
3. As the blood vessels in the gills dilate the surface area of the gills is expanded.
4. The expanded gill surface causes an increased influx of ions and water loss in saltwater fish. Conversely, freshwater fish experience an increased influx of water and loss of ions.

Adrenaline disturbs ion transport at the gill membrane, and both adrenaline and cortisol cause temporary changes in gill permeability which, in fresh water, results in dilution of the blood by excessive gain of water. Avoid handling your fish at all cost. Spooking or stressing the fish, such as tapping on the glass or playful nibbles from tankmates, will cause this surge in adrenaline.