Countless fish become stressed and fall ill, get injured or die as a result of accidents and environmental pollution in the aquarium.

In fact, most of us don't practice what we preach. We are all guilty of neglecting a loved one or even taking him or her for granted at some point, especially when everyday stresses take over.

If you want to avoid the nasty shock of chancing upon your fish lying on the floor, dead or otherwise, ensure that your aquarium has a close-fitting hood. Some species like arowana are capable of jumping to great heights, and can thus easily leap to their deaths from an uncovered aquarium.

When transferring your fish out of the tank, handle them carefully. The net you use must be large enough to hold the fish comfortably. You must also block the top of the net with your hand or a suitable covering to prevent the fish from leaping out. Use a good quality net to avoid damaging the fishes’ delicate skin.

To prevent your fish from getting cuts or abrasions, check gravel and decorative items carefully before placing them in your aquarium – they should have no sharp edges. Species like goldfish and carp often sift through the substrate in search of food, and in doing so, may accidentally get pieces of stone or gravel lodged in their mouths.

When changing the water, most fish hobbyists use a plastic tubing to siphon water from the aquarium into a pail. The suction force of the tube can sometimes be strong enough to injure the fish that swim too close to the open end that’s submerged in the aquarium.

Small fish could even get sucked into the tube and end up in the pail. If the fish is fortunate enough, it may remain unscathed; if not, it could either sustain minor scrapes or serious internal injury.

Countless fish die of oxygen starvation due to poor water hygiene or overstocking. When oxygen levels in the water become too low, fish (especially the larger ones) will experience breathing difficulties. Fish suffering from oxygen deprivation will exhibit these symptoms: very rapid gill movements and gasping for air at the water surface. In severe cases, the fish may die, often with their mouths agape and gill covers flared.

Your fish could fall ill because of diseases brought in by the addition of new fish or plants that have not been quarantined, or through water contamination caused by equipment and accessories that were not properly sterilised before being put into the aquarium.