Betta Fish is one of the various genera in the family Osphronemidae, and comprises small, colorful, freshwater ray-finned fish. Betta fish feature a unique organ called the labyrinth, which enables it to breathe atmospheric air. Thus, these fish are able to thrive in low oxygen water conditions such as rice paddies, drainage ditches, large puddles and slow moving streams. In all there are 28 known species of betta, of which the B. splendens or the Siamese fighting fish is very popular in aquariums. Since these fish are easy to care for, they are popular aquarium fish. When feeding and water conditions are not maintained properly, then the fish is likely to develop an illness. There are several diseases that can affect this fish. Here's an overview.Fin Rot disease: The first noticeable signs of this disease are the presence of tiny holes on the surface of the fin. The betta fish appears drowsy and hovering over the water surface. Dirty and poorly maintained water causes this disease. Moreover, it can also get itself damaged on certain obstacles in the fish tank, such as plants, etc. Any such obstacle must be cut or removed. Using fungal medication to treat the fish will be helpful. To avoid this problem, one must make sure that the water in the fish tank is changed regularly. Ich: White spot disease or ich is a disease associated with ongoing fluctuations of water temperature. The betta fish appears to have tiny white spots resembling white [Betta fish Fighter Fish] grains of sugar on its body and fins. This disease is caused by a ciliated protozoan parasite named Ichthyophthirius multifilis. These protozoans are present in the water of all aquarium tanks, except those tanks which are filtered through ultra-violet sterilizing units. They are introduced into tanks along with new fish, plants, nets and equipment. When the temperature drops below 27 °C (80 °F), their outbreak occurs. Maintaining a constant temperature helps prevent ich outbreaks. Adding salt or sodium chloride to the water helps reduce the infection. Medications such as malachite green or methylene blue are available for more efficient control. Fungus diseases: Poor water conditions or damage to the fish leads to fungus diseases. White fluffy growth appears on the mouth, fins and eyes of the betta fish. This disease is contagious and can spread rapidly. To reduce the infection, addition of common salt or sodium chloride is recommended. Malachite green or methylene blue are available for more efficient control. Fish with torn tails and fins, are prone to be attacked by a fungus called Saprolegnia. Velvet disease: This disease causes yellowish, granular, patchy marks along the body of the fish. The fish appears to be sprinkled by golden sand or pepper. This disease spreads rapidly and is the result of poor quality water, water changes, stress or chilling caused by transportation. The infected tank must be drained, washed in copper sulfate solution and then rinsed. Dropsy: This disease is the result of internal bacterial infections and causes the sides of the fish to bulge and the scales to protrude. High nitrate levels, over feeding and poor water conditions are the probable causes for this illness. Treating this illness is difficult and require veterinary advice. Besides the above mentioned illnesses, there are also some other diseases such as Popeye, and swim bladder disorder which affect this fish. How do I know if my Betta Fish is Dying?Appearance: The illness causes alterations in the appearance of the fish. The body may show the presence of red spots, white cottony patches, lumps, etc. One or both eyes may appear to be swollen or protruding, and the gills may not close completely, remaining open halfway. The scales may be raised resembling pine cones. The belly may appear abnormally swollen and protruding. The tail and fins may appear blackened or spotted. Overall, the fish may appear paler, duller and darker. Appetite: Betta fish are voracious feeders and eat properly daily. Lack of interest in food implies something is wrong. Sick fish may even spit food out of his mouth. Behavior: Healthy fish are active swimmers. When something goes wrong, the fish becomes lethargic and may lie at the bottom of the tank, coming up only for air. They may also stay at the surface in a corner. If the fish is infected by a parasite, then the fish will appear to rub its body on any hard object, in order to scratch itself. Diagnosing a sick betta fish will become easier as one spends more time examining the fish. Daily examination will train one's eyes to detect even the slightest change in the fish's body language and appearance.