Once all sign of gill movement has stopped, placing the fish in the freezer until fully frozen will make double sure the fish is dead and can be disposed of safely. Clove oil, like the anaesthetics MS-222 and benzocaine hydrochloride, is effective in achieving euthanasia.
Next time your fish are sick, the remedy might not be farther away than your kitchen table. Ordinary table salt (Sodium Chloride or NaCl) is a useful remedy for the prevention and treatment of several freshwater fish diseases.
Most fish are slightly denser than water, so sink immediately after death. However, like a drowned human, they become more buoyant over time as bacterial decomposition produces gases inside the body. Usually, enough gas builds up in body cavities to make the corpse float, like an inflated balloon.
If fish are experiencing acute stress (i.e., gasping up at the surface, lying on the bottom and not moving, or darting around the aquarium), you can be pretty sure that the water has been poisoned in some way. Maybe cleaning sprays got into the aquarium, or something released toxins into the water.
The Water Flow Is Too Strong
Many fish species prefer a calm water environment. If the tank water current is too strong, the fish might struggle to swim or eat comfortably, preferring instead to gravitate to the bottom of the tank to escape the water flow. That leads to stress, and the fish might even starve.
Dead fish float upside down because they fill with light gases. The muscles and bones of the spine are heavier, so fish float belly up.
Check the fish's eyes.
If they're sunken, your fish is dead or near death. Look for cloudy pupils, which is also a sign of death in most aquarium fish. If your fish is a pufferfish, walleye, rabbit fish, or scorpionfish, occasional eye cloudiness might actually be normal.
A dead fish cannot stay long in a tank before it contaminates it, and it should be removed as soon as possible. The longer the dead fish remains in the tank, the more it will pollute the water. It's advisable to remove fish within a few hours of its death.
There are many reasons why fish in your tank keep dying. A few reasons include stress, incorrect tank setup, overfeeding, diseases, and much more. To a beginner, it could look like your fish died for no reason whatsoever.
Place the goldfish in a container filled with cool water from his tank. The cool water contains oxygen and will help to revive your fish. Some experts also suggest placing your goldfish right back into the water in his tank, even if he appears dried out.
When Disease occurs: The most appropriate time to consider euthanasia, is when a disease occurs. In cases when diseases are highly contagious, or very hard to treat or even untreatable, then the old adage of one bad apple in the barrel, can be synonymous with one sick fish in the tank.
Loss of appetite. Weakness or listlessness. Loss of balance or buoyancy control, floating upside down, or 'sitting' on the tank floor (most fish are normally only slightly negatively-buoyant and it takes little effort to maintain position in the water column) Erratic/spiral swimming or shimmying.
Add 1 tablespoon (Tbsp) of salt per 3 gallons of water. You can pour the salt directly into the aquarium or hospital tank, but some people like to dissolve the salt in a small cup of water first. This level of salt is like using Neosporin topical ointment for a small cut (in other words, it's not very strong).
Neurobiologists have long recognized that fish have nervous systems that comprehend and respond to pain. Fish, like “higher vertebrates,” have neurotransmitters such as endorphins that relieve suffering—the only reason for their nervous systems to produce these painkillers is to alleviate pain.
A dying fish might have some obvious external symptoms like cut-up fins, abrasions, inflamed gills, or other signs of parasites. Some behavioral changes might include erratic swimming around the tank, laying sideways on the substrate, gasping for air at the water's surface, or scratching against hard surfaces.
The most common cause of fish kills is suffocation due to lack of dissolved oxygen. Most dissolved oxygen is produced by algae and aquatic plants through photosynthesis. A lesser but also important source of oxygen in water is diffusion from the atmosphere, which is enhanced by wind-induced surface water turbulence.
After the fish dies there is no more DO being ingested and the air in the bladder starts to dissipate, causing the fish to sink to the bottom. After a few days, the internal organs of the dead fish decompose and a gas is formed. This gas causes the fish to once again float.
If your goldfish is swimming sideways or upside-down, it may have swim bladder disorder. Constipation, enlarged organs, or infection can all cause the swim bladder to stop functioning properly. Swim bladder disorder refers to issues affecting the swim bladder, rather than a single disease.
My fish is floating on its side but still breathing. What do I do? It sounds like your poor little fish friend may be having a swim bladder issue. I had a few fancy goldfish (mostly lionhead Orandas) and one in particular, Stewart, had a swim bladder problem.
Other possible causes are overfeeding and improper water quality. Sitting on the Bottom: If your fish is spending lots of time at the bottom of the tank, it may be normal behavior. Many fish, like catfish, are bottom-feeders and spend their time there. Fish also often sleep at the bottom of their tank.
This can be easily done using an air pump, performing large water changes, manually stirring the water, or placing a fan near the aquarium. Oxygen, in particular, dissolved oxygen (DO), is one of the most important indicators of water quality, as it is essential for the survival of fish and other aquatic organisms.
This can be due to overeating, overconsumption, low water temperatures, bacterial infections, parasites, or other impaired organs affecting the bladder. In these particular cases, the fish can end up with a distended belly, curved back, impaired swimming, or even death leaving them floating on top of the water.
Positive buoyancy disorder, where the fish floats at the surface or on its side, is the most commonly presented form of swim bladder disease, especially in goldfish. Most likely, the cause is overinflation of the swim bladder. Overinflation usually takes place in the posterior chamber.